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Hell, those aren't big ! (Read 138878 times)
Steve Deckert
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Hell, those aren't big !
12/25/02 at 18:02:48
 
It was a cold winter night just before Christmas, a hot fire in the wood stove... lots of power tools, wood and beer with too much snow for anyone to bother you.  Good tunes in the background and no phone or computer.  DECWARE's self-prescription for a badly needed vacation - results pending.

Paul and I have been building a new pair of speakers for ourselves.  You may remember from taking the visual tour of Decware, the Bendi speaker(as it has come to be known)?  

Just thought it would be fun to share some pics of our recreational activities as they happen.  

I'll be adding more pics as things progress over the next few days..

Cheers  ;D



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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #1 - 12/25/02 at 18:15:00
 
COOL!  8)I can picture Terry making a pair of these for his EV's. Grin I'd love to have big efficient horns in my living room, but I don't really want to lose my wife at this time, so it'll have to wait.
Look forward to more pics.
Dave Smiley
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Terry
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Re: Hell, those aren't big !
Reply #2 - 12/26/02 at 01:08:09
 
Hey flip those babies over with the speakers on top and they would be perfect!  I wish I lived closer to someone that would help me build speakers, I have to make jigs to hold the other end most of the time.  Takes me as much time making things to take the place of another person than to make the speakers.  I can now cut a piece of MDF by myself with great precission.

Keep us posted Steve, I like this kind of project.  If only I had the room for the Jensen Imperial Horns, that project sure looks a like the Imperial horn, but a little smaller.

TG Grin
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« Last Edit: 12/26/02 at 08:45:38 by Terry »  
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chrisb
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Re: Hell, those aren't big !
Reply #3 - 12/26/02 at 17:09:48
 
Steve: aside from the obvious weight factor, do you find any sonice advantages to plywood over MDF.  

If that's Meranti ply, watch out for slivers - they'll dig deep and fester for a week if you let them

Is that power bar UL approved?

Can't wait to see the grill covers (inspired by the famous Ed Shilling leopard skin "twins"?)

Nice work on the updates to the listening room page, and thanks for the peak at the business end of the Dechorn.  Have you already named the driver(s) utilized in the main section?



cheers, and happy New Year's  all
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Steve Deckert
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Re: Hell, those aren't big !
Reply #4 - 12/26/02 at 18:11:43
 
Chris,

The only obvious advantage is strength.  MDF has more mass.  I've made these imperials from MDF before.  The weight is lucid.  These are being built from Luan (sp) a form of Redwood.  It can lay outside in the rain for the entire summer and will not warp.  I have gotten so many splinters from this stuff I just quit taking them out.

Terry,

These are the 1956 Imperials, however we have redesigned them to be twice as strong and twice as easy to build.  If you've ever seen the original 1956 plans, they are a joke.

We will be running these with the woofers on top.  I had planned to run coax drivers but I ran into a few things, 1) not very many to choose from, 2) pricey, 3) most have limited low freq. response.   I have decided to go with conventional pro woofers and load a horn with a good 2 inch compression driver.   We already know that this requires a serious horn lense for the compression driver to keep up.  With two 15's in each cabinet it will be even more difficult.

I needed a challenging project while Paul was gone so I decided to build the horn lenses myself.  I've done this before, but they were only 20 inches wide.  This time I'm going to make them bigger Smiley




The trick to building these is self-inflicted temporary ignorance of the compound radius angles involved.  Once you reach that state you may begin. (beer helps) Then once you've spent the entire day cutting parts the realization that there are severely complex angles to cut is balanced by the time you've invested and you really have no choice but to press on.



We've got both speakers together now, just working on the cleating and trim.  I'll post some more pics tonight or Friday.

Steve
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« Last Edit: 12/28/02 at 03:02:31 by Steve Deckert »  
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Terry
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Re: Hell, those aren't big !
Reply #5 - 12/26/02 at 23:32:34
 

[quote author=Steve Deckert  link=1040842968&amp/0#4 date=1040926303]

These are the 1956 Imperials, however we have redesigned them to be twice as strong and twice as easy to build.  If you've ever seen the original 1956 plans, they are a joke.

[/quote]

Steve,

Why are those plans a joke?  I think I have those plans.  Good idea on the plywood, I know redwood is very light for its size and strength.  If the wood you are using is similar it should be great.  To me the lighter more porous the wood the lower its resonance, and if it resonates below the usuable frequency of the driver all the better in my opinion.  Let us know what drivers you have chosen, and what efficiency you expect.  How about those horns Albert has Altec 811's 117 1w/1m?  They might keep up with two 15" bass drivers.

TG Grin


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Steve Deckert
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Re: Hell, those aren't big !
Reply #6 - 12/27/02 at 17:00:58
 
[quote author=Terry  link=1040842968&amp/0#5 date=1040945554]


Steve,

To me the lighter more porous the wood the lower its resonance, and if it resonates below the usuable frequency of the driver all the better in my opinion.  TG Grin



[/quote]

Terry,  actually the lighter the wood (less mass) the higher its resonance will tend to be.  You could not get a speaker cabinet to resonate below the usable frequency of a woofer unless it was concrete.  Most objectionable panel resonance in speaker cabinets can be found between 140 and 600 cycles.  As we add bracing or increase the panel stiffness (by adding another panel for example) we push the resonance up past this area so that it no longer effects the mid bass and lower mid range of the woofer. Grin

The plans are a joke because they are dimensioned like a puzzle with conflicting measurements and angles that don't jive.  Also it is obvious by looking at the original design that is was intended to be as light as possible.  The joinery is weak, as is the cleating technique.
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« Last Edit: 12/28/02 at 02:57:32 by Steve Deckert »  
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Terry
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Re: Hell, those aren't big !
Reply #7 - 12/27/02 at 17:20:40
 


That is interesting, that contradicts an experience I had here recently.  I use MDF in all my protype cabinets, because of ease of workability, but prefer plywood as it has a more natural sound to me.  Could it be I like the resonance of plywood?

Sooooooooo, what drivers do you have in mind?  I have been looking at several lately for bass horns and am extremely curious.

TG  ;D
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Steve Deckert
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Re: Hell, those aren't big !
Reply #8 - 12/28/02 at 02:45:20
 



Terry-  Yes, that's exactly what it is.  Plywood resonance can add objectionable OR pleasing colorations to the sound.  In the case of these Imperials, the bottom and top are double thick, as are the sides of the enclosure area (source of energy).  The horn is intentionally left as a single thickness and supported by large stiffening cleats.  This allows the large rear panel to resonate in a complimentary way.  Not unlike a musical instrument, careful design and control of panel resonance can make or break the signature of a loudspeaker.  It's an esoteric and ambitious way to build speakers making it obvious why so many just go for inertness.  Here is a photo of the rear panel and stiffening members from looking down the horn.

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« Last Edit: 12/28/02 at 02:52:16 by Steve Deckert »  
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Steve Deckert
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Re: Hell, those aren't big !
Reply #9 - 12/28/02 at 02:51:03
 


Here is another picture of the construction.  I think we're at around 5 sheets of plywood for each cabinet.  Basically around $300.  This will grow to about $500 by the time everything is said and done.  

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Corpsdriver
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Re: Hell, those aren't big !
Reply #10 - 12/28/02 at 03:07:16
 
I can hear the "Tim the Toolman" grunts from here...
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Steve Deckert
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Re: Hell, those aren't big !
Reply #11 - 12/28/02 at 03:10:29
 


Here is where we're at so far.  The cabinets are largely completed and ready for sanding, trim and finishing.  As you can see we couldn't stand it so we dug some old 15 inch woofers out of the bone yard and hooked them up.  I'll have a story about what happened when we turned it on.  Give me some time to write it - for now lets just say it was memorable!
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Steve Deckert
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Re: Hell, those aren't big !
Reply #12 - 12/28/02 at 03:23:21
 


Just kidding !  Okay back to working on the story!

Cheers,

Steve Grin
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« Last Edit: 12/28/02 at 03:35:25 by Steve Deckert »  
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thedude
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Re: Hell, those aren't big !
Reply #13 - 12/28/02 at 03:47:36
 
hehehe, weeeeeee
remember to wear ear protection when blasting those monsters, those high frequency horns look awsome, what is the low cuttoff, and i like the way you made them, just cut, bend and glue right? Smiley -Matt
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« Last Edit: 12/28/02 at 03:49:57 by thedude »  
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Steve Deckert
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Re: Hell, those aren't big !
Reply #14 - 12/28/02 at 04:28:00
 
The story about a first test listen to one cabinet in mono.

As I mentioned, we couldn't stand the anticipation and even though drivers have been ordered we just wanted to hear something come out this new horn.  We dug around and each of us found a woofer.  One was an old bass musical instrument speaker and the other was more along the lines of a PA driver.

The idea was that we would play the radio through one cabinet while we continued to work on them.  We thought we'd kind of get an idea how these cabinet alterations and improvements effect the bass.  To drive them I simply unhooked a floor monitor that was in the room and replaced it with an Imperial.  The amplifier behind it is a 400 watt Ross - the equivalent of a decent audiophile solid state amp.  

The source was a $70.00 Pioneer tuner with no antenna fed into the mixer behind my drum kit.  I listen to this stupid tuner through the monitors all the time when I work out here and have never once stopped and said, "gee that sounds really good!".  

As soon as we turned it on, Paul and I both stopped for about a minute and stared at it.  The sound I heard was so tight that I made the comment I thought maybe the two woofers were wired out of phase.  We listened to it for a few minutes frankly not sure what to think.  

Continued...

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Steve Deckert
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Re: Hell, those aren't big !
Reply #15 - 12/28/02 at 04:56:18
 
Continued...



The bass was very dry and super tight.  We quickly decided to change the send from the monitors to an aux channel where the output was not high-passed and more listenable.  At the same time both channels were mixed to mono so we wouldn't be hearing just one channel anymore.  From this point forward, the speaker was pleasing to listen to.  That was motivation to put on a CD and loose the crappy radio and so it was done.  

We listened to a couple of songs on CD at a high playback level looking for that familiar "Imperial Power" that wrecks the room also known as bass notes from hell and well you get the idea.  Remember, all prior models (about 6 pair) had all been done with a single 15 inch driver and built like the original plan.

I think we were both floored at what we were hearing.  First of all you forget the effortless power these speakers have - at least we did.  The most prominent thing that was different from prior models was the tightness.  The only speaker I've ever heard with bass that tight is my Acoustats.  They can play at 115 dB with less than 1% total system distortion and are the definition of tight.  This single Imperial sounded exactly like it but on steroids.  

When you attend a live rock concert with a sound crew that knows what's going on and is having a good night, you find yourself amazed by the power and the tightness of the kick drum.  Stereo speakers at home simply do not do that.  If you can picture this kind of sound in your mind, what we head come out of the Imperial was over twice as tight and extremely flat with bottomless extension that can and did shake the concrete floor.

Paul noticed that nothing in the room was getting wrecked.  By that he means vibrating.  Usually there are 20 things in the room that have to be quieted down because they buzz or rattle when you play the Imperial.  We just always thought this was normal but this time the sound pressure level was way louder than what it usually takes to start wrecking the room and not one peep from anything.  

Good room you say?  Not from this perspective, no.  There should have been 20 or more things that needed moved or weighted down.  We learned that the velocity and transient response (tightness) was so superior that it didn't give anything in the room time to be wrecked.  More like shooting a bullet through a door vs. someone pounding on it.  For both of us, this was some genuine enlightenment that basically means the nasty resonances of objects in your room are excited by distortion not pressure.

continued....
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« Last Edit: 12/28/02 at 05:00:46 by Steve Deckert »  
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Steve Deckert
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Re: Hell, those aren't big !
Reply #16 - 12/28/02 at 05:31:19
 
We ran through several more songs with different type of music and before you know it we weren't finishing the cabinets like we planned to.  

I think we both found it interesting that two grossly mismatched woofers could hit so precisely as one, not to mention sound even listenable in the midrange and high frequencies.  We simply ran them full range with a flat signal.  Now, unlike the original design that took months of playing musical woofers until we found ones that worked, this new cabinet design is obviously not going to give a shit what you put in it!

The horn lenses you see in prior pictures setting on top are not hooked up.  We don't have the drivers for them yet.

I expected to turn this speaker cabinet on, crank it a few times and reduce it to a background listening level so I wouldn't become tired of crappy mismatched speakers.  Instead we spent the rest of the evening from I guess around 7pm to 2am listening to it with bigger than life grins on our faces!

What clinched it was around 8pm when Paul flipped the crappy little tuner to our local public radio station that played jazz and blues.  It was the first time I heard the tuner sound good.  But it goes way beyond that...  Good is okay for about an hour.  Anything longer than that usually has to be great.  We had it cranked, but it was so clean that it didn't seem the 120 db it probably was.

Song after song, the cabinet just sitting there in the middle of floor and no good reason why it should be sounding this good.  Hour by hour and beer by beer we simply couldn't turn the damn thing off.  I started to have disturbing thoughts about the fact that I'm listening to "inferior" electronics when compared to our Zen Triodes, yet somehow this was sounding incredible.

Towards the end of the night, still listening to the radio in mono cranked to the wood on great jazz and enjoying it as much as stereo I had a good idea.  I decided no one would believe this if we told them, so I was going to get some proof.  All I had to do was go over to the computer by the mixer and start the recorder.  I used the two boundary mics also known as room mics (CROWN PZM) fed into the board in stereo.  

The songs kept coming and I recorded 4 of them.  Then we took a break and I just had to hear what the recording sounded like so I hit play.  Now, here we were sitting in the same room listening to a recording of the Imperial - ON the Imperial.  It was playing a recording of itself.  That was interesting.  There was a noticeable difference in the sound of the recording.  It was less detailed and less tight and slightly smoother sounding.  But considering we recorded the room and the speaker was 90 degrees off axis to the mics this effect is normal.

I have saved the recordings because I think you'll want to hear this.  Even though a conventional stereo will never be able to fully recreate it, you will get a taste of it, perhaps 50% which is enough to hear what is so special about it.

I'll post a link to a 30 second clip of song 2.  It is about 2.5 meg in size.  The whole song is 43 meg, and I'm trying to figure out what is the best way to present it.
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Steve Deckert
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Re: Hell, those aren't big !
Reply #17 - 12/28/02 at 05:39:14
 



Here is the sound clip.  It is a recording of us listening to Jazz on the radio in mono using one of the new Imperial cabinets exactly as it is shown in the picture.  

In short this is a recording of the new Imperial speaker in the room as pictured.  It is a 44.1kHz 16 bit stereo wav file.  

This is a stereo recording of one Imperial playing in mono.

Be sure to burn this to CD and play it on your real stereo.  Don't waist your time trying to listen to it on your computer.

http://www.decware.com/imperialsample.wav

Durring the recording I had Joe (who was also there- a friend of ours) take some shakers and walk by the mics so everyone could see this was not a faked recording.  In the complete recording you can hear all of us from time to time in the background.  

Steve


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« Last Edit: 12/28/02 at 05:53:03 by Steve Deckert »  
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Terry
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Re: Hell, those aren't big !
Reply #18 - 12/28/02 at 07:43:35
 
I can't believe it, I gotta hear the full song.  I have never heard 15" woofers produce such treble before.  What are those crappy woofers you dug up, you might be disappointed in the ones your ordered.  Which you haven't told us what drivers they are yet!!  One thing I have learned is not to under estimate vintage drivers, and pro drivers, they can do more than we imagine.

Cool suff keep it comming!  I think I might just have to make a pair of these, when will the plans be available?  But it have to wait until I get done with another project.

TG Grin

P.S. Looks like someone else has a Shopsmith.
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« Last Edit: 12/28/02 at 07:46:58 by Terry »  
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Peter
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Re: Hell, those aren't big !
Reply #19 - 12/28/02 at 11:44:39
 
Shocked
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Albert
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Re: Hell, those aren't big !
Reply #20 - 12/28/02 at 15:21:39
 
Ok now wouldn't it be wild if when you put in the "correct" speakers that you lost all the magic! I know you guys have thought about that Grin
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #21 - 12/28/02 at 15:37:47
 
Maybe the secret to the "magic" is the mis-matched speakers. Each could be correcting the flaws of the other.
Dave Grin
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Corpsdriver
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Re: Hell, those aren't big !
Reply #22 - 12/28/02 at 16:01:33
 
No way! That wonderful High End was your buddy with the shakers, right?  :o
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Re: Hell, those aren't big !
Reply #23 - 12/28/02 at 16:08:12
 
increadible... even the top of the ride and the splash were there... Once again, i am on my knees, facing east, bowing to the Deckert. you need to hang a sign on your shop door that says "Welcome to Mecca"
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Steve Deckert
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Re: Hell, those aren't big !
Reply #24 - 12/28/02 at 16:48:39
 
Yes, Paul and I had this exact conversation.  I personally expect to like the miss-matched pair better.  We plan to install the fresh woofers in the second cabinet and compare once they come in.  To keep costs down I'm going to be using some no-name woofers from China.  They might be a flop, if there are you will all know about it --- as the Imperial turns.

Like I told Paul, don't laugh, we may have to find another pair of miss-matched woofers that match these!

I agree, you all need to hear the entire song.  I will post the 43 meg file on the site soon.  I will also remove it shortly afterwards.  Perhaps a few days.  Those without high speed Internet could possibly do an all night download while they sleep.

I thought many of you would find the highs interesting... we did!  Hell, why don't you all drive or fly over here and we'll roast a pig on the wood stove and have another go at it!

I'll be honest here for a minute... what is really sick is the fact that a single cabinet playing in mono with a poor source, crappie wire, and so so solid state amp can be as rewarding to listen to as the high end gear in stereo.  And in many ways it goes well beyond it.  At least that is what went through my mind at least 40 times on Thursday night Smiley

Of course the main course still awaits.  A finished pair set up properly being run by Zen amps.
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earwax
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Re: Hell, those aren't big !
Reply #25 - 12/28/02 at 17:47:42
 
Stevie!...Sweetie! I can believe you and Paul put another set of Imperial's together. And I can believe your finding something magical about them...but, did I read this right..you let Joe within striking distance of them! You know Japan has Godzilla, and well, from past experience, Godzilla has met his match. I have no doubt Japan would reward us handsomely if we were to keep Joe safely contained here in the U.S.

I shall have to stop by sometime and give them a listen to.
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Re: Hell, those aren't big !
Reply #26 - 12/28/02 at 17:53:00
 


I posted this a while back, it is all about tone.  The only reason for trying to get a stereo set up correctly put together is to get the right tone.  Phase coherency is just one aspect of that.  What you are saying is not surprising to me in the least, we have been so misguided by manufactures.  In the realm of speakers, one thing has proven true, BIGGER IS BETTER.  I have got to make a pair of these speaker for my garage.  No matter how nice I make them look, I don't know if my wife will let them in the house, but I will try.  Perhaps when she is seventy and doesn't care any more I could hire a moving company to move them in the house then, but I gotta have a pair now.

I think those china cheapies might just work fine, but you have got to try a few different speakers in them to help us understand what will work and what will not.  I find pro-drivers and vintage speaker drivers to be more forgiving of enclosers.  I mean in the scale of 12  cubic feet, what is one foot here or there.

I guess Steve doesn't have to worry about WAF when his business is audio, you just go to work and enjoy.

TG Grin
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Re: Hell, those aren't big !
Reply #27 - 12/28/02 at 21:40:50
 

One more thing, I am real curious how 15" drivers sound when set up in proper stereo imaging, as they tend to beam start at round 600Hz.  So you would probably have a narrow sweet spot, and I wonder if they would sound as good on axis as the would slight off axis.  Just some thoughts I am wondering if a person can overcome.

TG Grin
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Re: Hell, those aren't big !
Reply #28 - 12/29/02 at 02:42:43
 
Wel that just proves, there's no substitute for a big a-s-s pair of speakers. I listened to the WAV file, and it sounded pretty good, but that's because I've got my WebTV box hooked into my home theater/surround rig.

Why do I bring this up? Well, my processor has five LEDs that glow with varying brightness to indicate the relative strength of the signal going to each channel. And even the TWO channel recording Steve made does have some embedded ambient/surround information.

When the recording started, it was like being transported into the room that the big ol' Imperial was playing in. I even played the thing a few times through, just to confirm it wasn't a mistaken impression. It was like I was in the room with the speaker. If any of you decide to burn a CD, try listening to it in a surround rig, preferably in a matrix mode with NO room simulations. You may be suprised.
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Re: Hell, those aren't big !
Reply #29 - 12/29/02 at 03:19:56
 
Hi Steve,
I am IMPRESSED... wow.  With junk drivers,even.  So when will the plans for the Decware Imperial become available?
Steve F
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Re: Hell, those aren't big !
Reply #30 - 12/29/02 at 05:00:46
 
C'mon now Steve let's have some plans and I will develope a 3D solid model of them on the computer; it would be a nice evening project. Oh if it was just as easy to build cabinets in real life as it is on the computer!
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Re: Hell, those aren't big !
Reply #31 - 12/29/02 at 12:15:03
 
Not real suprised:

I've always contended that speakers make the biggest difference in an audio system.

The top octave is highly over-rated (as is the bottom octave, but you have to have it on the recording and have the right room to listen in).  This is one reason why single driver speakers can work.

IMO, there's still a lot of life left in the single channel concept (cheaper, smaller, more coherent, many recordings don't support a decent stereo image anyway).

BTW, Wayne Parham from Pi speakers suggests filling the voids behind the panels with expanding foam.

Don't have a CD burner so I'm missing out on the recording.

I'm eyeing the end of my living room right now, looks like there's enough room to fit one on either side of the window.  You know, I've been wanting to reside the house anyway, maybe I could build them into a bump out and not lose floor space (the room fits the golden room dimension ratio as is).

Steve, please provide some specifications.  Could these be driven by a Select?
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #32 - 12/29/02 at 13:46:33
 
>Steve, please provide some specifications.  Could these be driven by a Select?<

Those things look efficient enough to be driven by anything, even a headphone amp. Shocked 8)
Dave Grin
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Re: Hell, those aren't big !
Reply #33 - 12/29/02 at 23:42:37
 

Steve,

What about drivers for the horns, what do you plan on using for the top end?  Looks like those lenses should be good down to about 800Hz at least.

TG Grin
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Re: Hell, those aren't big !
Reply #34 - 12/30/02 at 02:13:34
 
JLM,

In the original design filling the voids with foam would have really helped things.  This new version has no voids except in one spot.  It is cleated in five places.  Time will tell.

I will publish the new plans once I feel we are done with these cabinets and happy with the results.  Sounds like a pair built into your walls would be interesting!

Can these be driven by a Select?  I can think of no better speaker.  

Terry,

I've ordered some 2 inch compression drivers by Selenium for the horn lenses.  The drivers have an fs of 400 Hz.  The lenses should easily reach 500 Hz if I wanted to go that low. I plan to work on them sometime this week once the drivers arrive.

Steve

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EZ_Angus
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Re: Hell, those aren't big !
Reply #35 - 12/30/02 at 03:05:45
 

hi steve: awesome speaks! I have a pair of altec 416-8b's that I want to mate with my 802-8d drivers on 511-b horns. do you think your cab design could be adapted for a single 15 inch woofer? I'd like to build something fantastic for these great old parts, maybe even a wooden horn too?

envious angus
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Steve Deckert
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Re: Hell, those aren't big !
Reply #36 - 12/30/02 at 04:05:40
 
Here is the complete song from which the clip was taken.  It is 46 meg.

http://www.decware.com/imperial1.wav

This should be interesting!

Cheers,

Steve
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Terry
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Re: Hell, those aren't big !
Reply #37 - 12/30/02 at 08:00:03
 
Darn, I downloaded it and I can't play it, with anything I have I have four programs that say they can play wav files, and none of them recognise it.  :'(

TG Grin

P.S. Steve, can you point my to where on your web site i can see a photo of the Imperial horns, with Bendi in it.  I just wanted to compare this one a bit.
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« Last Edit: 12/30/02 at 08:58:32 by Terry »  
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Peter
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Re: Hell, those aren't big !
Reply #38 - 12/30/02 at 10:03:17
 
Steve, I dont' mind since I'm on Broadband anyway, but mightn't it be more convenient (and less costly in terms of bandwidth) to zip the file or compress with some lossless audio packer?
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Corpsdriver
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Re: Hell, those aren't big !
Reply #39 - 12/30/02 at 14:32:01
 
I burned a copy of the recording, and took it to my HT room, and played it in several configurations beginning with stereo w/o sub on my KLH model 17s, then my model 4s. then my a/d/s l-1590s and so on. THOROUGHLY IMPRESSED! I think i am going to put my 3 main pairs up for sale and build a pair of Imperials! And no, Elvis, (my HWK-15) aint leavin the building! I will deliver anywhere in the Pacific NW!
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Albert
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Re: Hell, those aren't big !
Reply #40 - 12/30/02 at 17:03:58
 
I can't play it with Windows Media Player or Real Player..oh well...
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Corey
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Re: Hell, those aren't big !
Reply #41 - 12/30/02 at 18:23:36
 
Terry,

Bendi can be seen laying in the Imperial during the start of the visual H. Fidelity tour as well as in an article about hi-fi and home theater.

Corey
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Peter
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Re: Hell, those aren't big !
Reply #42 - 12/30/02 at 21:42:04
 
I think the file's corrupt, media player et al don't like it, I was able to put it into cooledit though.  Perhaps you need to burn it to CD or open it with a program that doesn't require it all in memory at once?

I had a play with it, it does sound amazing, there's basically nothing in the registers abouve 16,000 Hz except a band of noise between 18KHz and 20KHz which probably comes from the recording media.  I did a high-pass filter at 14KHz and it still makes very little difference to the sweet ride cymbal.  This is what we'd expect from a pair of 15" drivers, I suppose, but it just goes to show that timbre and voluminous bass can make such a huge difference.   I was surprised to note that there seems to be a stereo image, Bass is where it should be... along the bottom.  The sax is somewhere right of centre and the ride cymbal seems to be off to the left.  Very odd.

The spectral analysis shows the track to be absolutely saturated with below 100hz.  Who needs subwoofers!?  That's rib-crushing bass Cheesy I suspect the real thing sounded more tight than the recording, and it especially suits that music, but I was also surprised to hear the quality of the announcer's voice, too.

I think this beast is going to sound amazing with the top end drivers in.

For those of you who couldn't hear the file, I took the liberty of putting a high-quality mp3 up here.  I don't want to damage anyone's self-calibrating hearing  :P but it's super-high quality variable bitrate and to me sounds easily as good as the original.  It's the bandwith I'm more worried about Grin

PS - I'd love to hear those beauties belt out some piano when they've got their top bits in.  Even without, I bet they sound about as close to the real thing as you can get.

erratum: high-pass should read low-pass.

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« Last Edit: 01/01/03 at 03:54:18 by lindseyp »  
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DrN
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Re: Hell, those aren't big !
Reply #43 - 12/30/02 at 23:00:11
 
On Steve's file Win Media Player opens but it come up "data is invalid".

Peter, the MP3 works. Thanks!

Den
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« Last Edit: 12/30/02 at 23:07:20 by DrN »  
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Terry
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Re: Hell, those aren't big !
Reply #44 - 12/30/02 at 23:28:15
 


That is what my computer keeps saying that the file is corupt.  Thanks for the mp3 file Peter, I was able to play that, although I don't know if I want to waist a CD for it though I haven't decided.

This is what I think, the shakers, high hat, cymbles, and tamborine, were all being played by Steve and company.  The rest was comming from the Imperials, even at that the imperials sounded great.  You can not beat high efficiency drivers.  I of course on my computer did not get the sense of huge bass, but the rest of the tonal quality was great.  I suspect these speakers will be much happier with vintage high efficient woofers such as Electro-Voice (that would be my first choice), and Altec drivers.  I also would think many modern pro and high efficient drivers would sound great as well, but just not quiet as tonally balance as the vintage drivers, much like the ones Steve has in their now.  In fact the on driver looks like an EV driver.  Steve can you tell us the mismatched pair you have in their now.  I also think having a mismatched pair would have some advantages, as you could get a little better tonal balance.   Both are feeding the same horn, but are separated by their own enclosers aren't they?

Anyway  shows to go ya, you can't really change universal laws,  what men did 60 years ago to make music sound good still will today, we just made a few changes but we really didn't make much more progress.  We just figured out a whole bunch more about what won't work.

TG Grin
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #45 - 12/30/02 at 23:34:33
 
>Anyway  shows to go ya, you can't really change universal laws,  what men did 60 years ago to make music sound good still will today, we just made a few changes but we really didn't make much more progress.  We just figured out a whole bunch more about what won't work.<

To judge by some of the speakers being made today, some people still haven't figured out what don't work.
Dave Grin

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Peter
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Re: Hell, those aren't big !
Reply #46 - 12/31/02 at 05:49:25
 
If you haven't got studio speakers or good headphones with a suitable soundcard or audio interface on your computer, I highly recommend burning a CD.  It's difficult to appreciate the sheer depth of the recording.  -- and these day's a blank CD sells for less than 50c.

The cymbals sound like they're in the room, it's true, but I'm 99% sure they're part of the original recording.

The voice at the end's a dead giveaway, all the S's and T's are clear as a bell.
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« Last Edit: 12/31/02 at 05:50:02 by lindseyp »  
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Terry
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Re: Hell, those aren't big !
Reply #47 - 12/31/02 at 14:32:52
 

You think I will get all that from the mp3, as the original file will not work with any of the programing I have here.  mp3's are Ok, but they are somewhat compressed and don't give you a good sense of imaging.   The original wave file if it worked proabably would do a little bit better, don't you think?

TG Grin
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Peter
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Re: Hell, those aren't big !
Reply #48 - 12/31/02 at 15:05:06
 
To be honest, I don't think so.  (addendum: I mean I think you will get all that, I don't think you'll lose the imaging Cheesy) The source of the recording is one speaker cabinet, so other than the background shakers etc, most of the 'image' is artificially created.  Whether it was caused by the recording or by the mismatched drivers who's to say.  What I will say, though, is that the mp3 is recorded at a very high variable bitrate.  i.e. when not needed, the bitrate is low for better compression, when needed, the bitrate goes up to 240bps, which is easily high enough for 'cd quality' recordings and way higher than most anything you'll find on the internet.

On my studio sound module and fairly good sony headphones I couldn't tell the difference and was satisfied with the quality and the imaging (inside my head), or I wouldn't have posted it.

After all, what the original file contained was a noisy recording done (I'm assuming) on PA kit, of FM radio played through mismatched 'cheapo' 15" drivers with no tweeter.   Blank between 16-18Khz and full of recording noise between 18-20Khz.  I even left the recording noise in!  Believe me, mp3 or original, you don't lose the jaw-dropping disbelief in what you're hearing.
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« Last Edit: 12/31/02 at 15:06:53 by lindseyp »  
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MagMan
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Re: Hell, those aren't big !
Reply #49 - 12/31/02 at 15:41:11
 
I love my Walsh 4's but thave had them for many years and have the bug to change to some kind of horn. (4's are for sale) they are in my basement rec room which is quite large. I have about 12 hours of searching the net in the past few days (I know get a life) for some rear loaded horn plans EXACTLY like these (single 15 would be better). All I found was more PA stuff.  I just scored a pair of old Frasier wood horn lenses on e-bay. And I just ordered some Selenium drivers. I have a very old set of EV drivers as well along with the matching EV tweeters, ST35's I think they were. I was almost settled in on some Altec 816's till I found this thread, Steve, post the plans, please. I just ordered the crossover parts.
Mike
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Cayenne
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Re: Hell, those aren't big !
Reply #50 - 12/31/02 at 15:52:03
 


[quote author=DrN  link=1040842968&amp/30#43 date=1041289211]
On Steve's file Win Media Player opens but it come up "data is invalid".

Peter, the MP3 works. Thanks!

Den
[/quote]

Hmm...perhaps this is a DRM issue? Particularly if it was recorded with Windoze...??

I think the last version that came out, had it as an 'option' that you can turn off....

I'm guessing soon, that this will no longer be an option....

Anyway, you might check on this?

C
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mikes
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Re: Hell, those aren't big !
Reply #51 - 12/31/02 at 18:25:37
 
Regarding Steve's adaptation of the Jensen Imperial, perhaps some of you would find these links interesting:

Jensen Imperial horn drawings:
http://home.earthlink.net/~lotusblossom/_wsn/page3.html

some Imperial pics:
http://community-1.webtv.net/KerrB/VINTAGETUBEAMPHORN/page6.html

Peace,
MikeS
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Steve Deckert
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Re: Hell, those aren't big !
Reply #52 - 12/31/02 at 23:51:37
 
Peter,

You are right about piano.  And Terry,  I did not touch the drum set.

As for the links, this is the "cut-corner" home version of the Imperial.  It was designed for a single 15 as was the original model Paul and I built.  Paul and I have built a pair of these also, still have them.  They do not compare to the full size imperial with one 15.  They really do not compare to the new models.  They do not go much lower than 37 Hz, and they sound sloppy compared to these new ones.

I got the compression drivers yesterday and one was dead out of the box.  I installed the good one on the cabinet with the two 15's and was pleased to find I need do nothing else.  I simply hung a 15 uf SOLEN cap on it and wired it up.  

The Solen compression driver is claimed to be 107dB with 1 watt.  I kinda expected to have to pad that down a bit, but that is not going to be the case.  In fact it could be 1 or 2 dB louder.  Adding it completely cleaned up the 15 inch woofers, now that the highs have a place to go.   After hooking it up, I realized in just a few minutes that all my suffering with the bent wood lenses was well worth it.  WELL worth it.  Amazing.

Today, a few of us found ourselves sitting around in the shop listening to public radio again.  I don't think anyone moved  for about 2 hours.  It really is amazing how just one cabinet can fill the room and have "stereo imaging" be the farthest thing from your mind.  It sounds so real, so live.  The incredible power it has even at low levels let you feel every note.  Besides piano, I have found horns to sound incredible, and acoustic bass on this speaker simply wastes Pauls 200 watt CLASS A all tube bass rig - also using 2 15 inch drivers.  Imagine that for a  minute.  Imagine an acoustic bass growling with textured low notes that are tight and powerful enough to make a good sounding electric bass sound stupid.  Well, this is what is happening.  

Got to go, we have a big get together tonight.

Steve
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Brian
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Re: Hell, those aren't big !
Reply #53 - 01/02/03 at 03:01:32
 
Peter said: "The source of the recording is one speaker cabinet, so other than the background shakers etc, most of the 'image' is artificially created. Whether it was caused by the recording or by the mismatched drivers who's to say."

This makes me think the speakers may sound best with mismatched drivers when listening to only one, but when listening to both of them well matched drivers may be neccesary to create a sound stage.  
Not an important point since Mr. Deckert will do an empirical test rendering my speculation moot, but I love to speculate.  
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« Last Edit: 01/02/03 at 03:38:31 by Brian »  
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Audioillusion
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Re: Hell, those aren't big !
Reply #54 - 01/03/03 at 09:09:28
 
Mr. Deckert,

You certainly tell a good story. I'm skeptical of the sound I'm hearing out of the horn speaker you've built. It's sounds simply amazing. I know you had a stereo microphone set-up due to the background noises I'm hearing (some howling?, shakers, talking). That's not what amazes me. It's how 3D the jazz music I'm hearing sounds.

I listened through a pair Sennheiser HD590's directly out of my sound card so I'm certain I'm receiving a relative realistic presentation of these particular recording. Direct to DSD recording sound eerily realistic while using these headphones so I'm confident I'm hearing the full potential of this recording due to the potential I know these cans contain.

I'm very skeptical of these horns sounding as "life like" as the (short) wave file I've heard.  The full length wave file has been official labeled as a lost cause. I've tried the MP3, it does sound like an MP3 compared to the wave file, in other words it sounds like a four letter word. However I think the MP3 and the wave file are of the same source so I'll say these recording came from the same source. I also will say that the shakers prove the recording is legit.

What I don't understand, why does the jazz sound stereo and life like through only a mono 15" bass guitar drivers. What makes a horn sound so life like?
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« Last Edit: 01/03/03 at 09:12:07 by Audioillusion »  
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Jimmy
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Re: Hell, those aren't big !
Reply #55 - 01/03/03 at 11:53:22
 
I'm glad I poked my head in to take a peek at what you guys have been up to.  I liked the shakers myself.  Real purist recordings are so nice sometimes.  None of the over compressed flatness of the "finished" products offered as music.

As for the sound from the horn...  I think its pretty cool that you could capture a reproduced source with such finess.  I do however question the accuracy of all of us listening to a reproduction of an event through our own colored speakers and equipment.  I know you mentioned that we would only be exposed to the concept of the event and that we wouldn't have the true experience reproduced for us because of this inconvienence, but I do wonder if what we're all hearing is the same thing?
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Terry
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Re: Hell, those aren't big !
Reply #56 - 01/03/03 at 16:10:07
 

I don't know about you Jimmy, but I hear a lot, even though this is not what I would listen to everyday for pleasure.  I have done enough recording that I know the dynamic range protrayed in this recording is incredible.  I wonder how loud it it is, sounds pretty loud to me, with the voices in the back ground being faint.  But then I have this vision of the Mic being about ten feet from the speakers too.

Dynamics in recordings are what make it sound natural, otherwise the back ground noise comes up to a level that it is appearent.  Dynamics are a very important part of sound reproduction, and the weakest link are our speakers most of the time.  When I was in the industry our studio monitors were 104dbs 1w/1m, they put speakers in the studio like that for a reason, and it wasn't because they didn't have enough power.

TG Grin
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Jimmy
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Re: Hell, those aren't big !
Reply #57 - 01/03/03 at 18:32:36
 
Oh, and I forgot to mention...  Steve, Those things kick ass!  :D  Very impressive horn's you've built.

Granted I've been out of the scene around here for a while, but we've always seemed to be pretty happy with what we're using.  So I'm just curious as to how much of the actual horn we're getting across on this little file.  I'm very pleased with the sound from the file, but it does remind me of radio quality in dryness. (which is why I was enjoying the moving shakers so much)  Volume is another issue as you correctly stated the background voices are very faint.  I'll admit I only listened to the file once and was playing it straight through my sound card into my preamp.  So right there is a source of variation from the source I'm using vs what most of you probably did. (I don't have a burner on this comp)  I can say that the soundcard i'm running is rather neutral for the most part. (I've tested it as an RTA with software and a decent mic)

I like the premise of the experiment.  I thought it was neat hearing a very dynamic set of doomed speakers perform like champs, but I just wonder how much of the experience is lost in transmission.
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Peter
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Re: Hell, those aren't big !
Reply #58 - 01/03/03 at 19:54:26
 

[quote author=Audioillusion  link=1040842968&amp/45#54 date=1041584968] I've tried the MP3, it does sound like an MP3 compared to the wave file, in other words it sounds like a four letter word. [/quote]

I strongly dispute this.

Firstly, what soundcard are you using?  There are not many soundcards whose amps are good enough for your headphones.  I was using a Roland SD-90 24/96 studio audio interface, and I couldn't tell the difference.  Admittedly I wasn't using 'audiophile' headphones, since I didn't have them with me,  but even so...

If it really does sound that bad, then surely you can tell the difference easily between clips if I post a/b of the original file, and the mp3 converted back into WAV.  Fancy a challenge?   Grin I wasn't using LAME, just cooledit (another studio-quality piece of software btw), I'm sure you could not tell the difference if I used LAME, and I'm pretty sure the guys at syntrillium would be upset if you could even with cooledit.  

Or maybe it's just your mp3 software which you need to change, but that too I find odd, most software is capable of accurate playback.  What software are you using?

Damn I need my 'real' gear.  I'm fed up of making compromises.

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Peter
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Re: Hell, those aren't big !
Reply #59 - 01/03/03 at 20:39:14
 
I take that dispute back. I was going to put a 'mp3 challenge' up as a new thread to see if you really could tell the difference so easily, despite that I previously couldn't.  So I prepared a clip, and then when I A/Bd my specially prepared clip the difference was indeed obvious -- even with my laptop soundcard.  I should have used LAME to encode it.  Sorry about that folks.  It must be the syntrillium plugin.


--Addendum:  Even so, the crazy imaging is still there.  Where did that come from?
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« Last Edit: 01/03/03 at 20:41:20 by lindseyp »  
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steve_f
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Re: Hell, those aren't big !
Reply #60 - 01/03/03 at 21:13:29
 
Hi Everyone,
I,m just wondering if all of us are hearing some kind of attractive phasing anomoly from using two mismatched woofers in the Imperial speaker.  Steve, have you tried a pair of matched woofers yet?  Honestly, I wonder what both Imperials sound like, even with mismatched woofers.
Take care,
Steve F
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #61 - 01/03/03 at 22:32:54
 
>Even so, the crazy imaging is still there.  Where did that come from?<

If the recording was done with a pair of mics for stereo, there will be some kind of image even from a mono source. The room itself will contribute different sounds from different directions, thus a stereo image of some sort will develop. At least I think so.
Dave Grin
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Audioillusion
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Re: Hell, those aren't big !
Reply #62 - 01/03/03 at 22:53:41
 
[quote author=Peter  link=1040842968&amp/45#59 date=1041626354]
I take that dispute back. [/quote]

I was really interested in your challenge. The perceived difference in the MP3 and WAV is blatant in my opinion, glad we see eye to eye. I've done MP3 A/B's before, I nailed the MP3s every time.

I was listening through a stereo receiver that was connected to my sound card so amplification wasn't much of a problem. Especially since my phones are really efficient. I know the DAC in my sound card isn't the best but the recordings were still very reveling.

[quote author=Peter  link=1040842968&amp/45#59 date=1041626354]
--Addendum:  Even so, the crazy imaging is still there.  Where did that come from?
[/quote]

My guess is since Steve's recording was so pure, meaning it wasn't damage by a recording "engineer", and since Steve's horns are able to accurate reproduce the signal, the way our brain perceives the music is true to the actual music which is why it sounds life like. Even through we weren't listening to a stereo pair of speakers, the horns were still able to transmit the necessary acoustic information to our brain. Remember the brain is what perceives a sounds location by analyzing the properties of the sound. Not sure exactly how our brains do this, but I?m sure the ?Illusion? of a 3D played-back sound has more to do with preservation of the acoustic information than the number and location of the speakers.

It?s my belief that the best possible recording is one with the least amount of distance between the microphone and our ears. In other words: the simpler the recording the better. For example: every time an EQ, mixers, compressors, ect. is used during a mixing session, information that our brain needs to recreate the true sound of the music is lost. These tools make the original acoustic information untrue to the music. It?s like copying a video tape, with each copy of a copy the video quality degrades. A lot of mixes are guilty of something similar. In Steve?s recording, everything was preserved why it sounds life like.
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Peter
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Re: Hell, those aren't big !
Reply #63 - 01/03/03 at 23:02:50
 

[quote author=Audioillusion  link=1040842968&amp/60#62 date=1041634421]
I've done MP3 A/B's before, I nailed the MP3s every time.
[/quote]
Hehe.. I think with the right tools, (i.e. LAME on the r3mix setting or some of the 'better' alternatives) I could persuade you otherwise.  I have done A/B on those before with far better kit and been gobsmacked.

But not right now.. it's late Wink

As for the image, I'd *really* like to know if it was there 'live'.   I seriously doubt it.  Remember Steve's recording was far short of 'audiophile' quality, so that might have had something to do with it.

My secret theory is that all imaging is artificial Wink --either intentional or incidental --  how sought after it may be.  Especially 3D imaging.


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Albert
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Re: Hell, those aren't big !
Reply #64 - 01/04/03 at 05:48:22
 
Peter..dude..you are getting way too deep for me at this late hour, I mean I think I understood what what you said...and that scares me Grin
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Brian
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Re: Hell, those aren't big !
Reply #65 - 01/04/03 at 06:52:13
 
Audio Illusion wrote:  "It's my belief that the best possible recording is one with the least amount of distance between the microphone and our ears. In other words: the simpler the recording the better."

There is a good commentary on this at http://www.xs4all.nl/~rabruil/dongabor1.html  which is a site about Don Gabor's Remington record company in the early fifties.  Apparently Don did not have the money for elaborate equipment so he used simple stuff and accidentaly made great records.  Lots of fascinating biographies of classical pianists and violinists at that site too.  

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Corpsdriver
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Re: Hell, those aren't big !
Reply #66 - 01/04/03 at 16:04:14
 
Audioillusion wrote, Quote:
Steve's recording was so pure, meaning it wasn't damage by a recording "engineer"


You know, i may as well let the cat out of the bag. All recording engineers today are contracted by a government agency, to insert "damage" and subliminal messages. The end result is "mass birth control" by destroying the male libido, not to mention invoking paranoid delusions, and an inability to take amature recordings at face value. Roll Eyes

I Honestly dont mean to offend anyone, I just wanted to show contempt fot the "William F Buckley Jr." tangent that seems to surface at times in this forum...

Jamie

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Corpsdriver
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Re: Hell, those aren't big !
Reply #67 - 01/04/03 at 17:56:28
 
Boy am i gonna catch hell for that one... Shocked
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Steve Deckert
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Re: Hell, those aren't big !
Reply #68 - 01/04/03 at 18:24:15
 
If you do catch hell for it, I hope it's in a new thread!  

I have received 4 matched woofers for the cabinets.  Still waiting for a replacement compression driver. The new drivers are real nice, but I doubt they will fly.  We installed a pair in the other cabinet last night and everyone liked the miss-matched drivers better.  The new drivers do not have the midrange and I believe that is most of it, however it raises many questions.  

I'll try to do a complete update over the weekend with a few more pics.

Steve
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« Last Edit: 01/04/03 at 18:25:22 by Steve Deckert »  
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #69 - 01/04/03 at 21:04:40
 
There is an interesting driver for sale in the MCM Electronics catalog for $73.00 each. Part #55-1880. Specs are:
Power handling-400W (I don't think a Zen would be a threat)
SPL- 98dB/W/M 2.8V
Fs- 28Hz
Vas- 16.36 cu.ft.
Qts- .231
Qes- .274
Qms- 1.457
Xmax- 4.4mm/.17"
DCR- 6.6ohm
Magnet weight- 100 oz
Voice coil- 4"

Not sure how high up the frequency range will go. It seems to be hard to get large drivers that will go high these days.
  This driver sounds interesting for the money, and I think it would work in a horn. But then, what do I know  ::) Grin
Dave Grin
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Brian
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Re: Hell, those aren't big !
Reply #70 - 01/04/03 at 21:07:53
 
Sorry about bringing Don Gabor into this thread.  I will move him over to the music lover's forum.   Lips Sealed
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stone_of_tone
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Re: Hell, those aren't big !
Reply #71 - 01/07/03 at 18:42:20
 
Steve, I want to hear the latest.....I know...you said you will try to post over the rest of the weekend....I will be patient Roll Eyes

Stone of Tone 8)
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pmwoodward
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Re: Hell, those aren't big !
Reply #72 - 01/08/03 at 17:06:35
 
Steve, too funny!! that A-bomb gave me a good laugh!
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Steve Deckert
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Re: Hell, those aren't big !
Reply #73 - 01/11/03 at 23:29:17
 
Okay, I think an update is in order!

First a few observations about the miss-matched drivers.  One came from a Plush Bass Cabinet and featured a 2 inch voice coil.  It has incredible tone, and basically no mids.  It was the woofer on the right in the pictures.  The left woofer was an inexpensive Eminence PA speaker.  It not only has a midrange but has a 10 dB rise in the midrange a 2K.  This is why the speaker had such good presence and tone.  

When you walked up to the speaker and listened to each driver at close range, the one on the right sounded wonderful and the one on the left sounded like crap - enough to make you instantly take 3 steps back.

The new woofers I ordered came in.  They are probably not ideal for this project, but we're thinking about selling them for sub woofer projects so I wanted to try them.  We mounted a pair of them in the other cabinet and as I mentioned before, everyone leaned towards the miss-matched pair in the other cabinet.

The new woofers also roll off quickly, and sound very similar to the Plush woofer with the good tone.  After playing around for a couple nights I decided we would need more midrange like we had with the miss-matched pair, but without the nasty peaks.

I had a pair of Peavey woofers that when compared to the miss-matched pair fell right in the middle.  The reason the midrange was important to get from the woofers rather than getting it from the bent wood horn is in a word - "hit".   The snare drum crack that comes off so tight you jump, and the kick drum that pops your chest is a function of the higher frequency response of the 15 inch woofers.  The Peavey woofers had the "hit" we needed but no low bass.  The new woofers have the low bass but lack the snap.  It is difficult to find both in a single 15 inch driver.  The new drivers has response down to 30 Hz.  The Peavey drivers are down to around 70 Hz.

We installed one of each in each cabinet.  We put the Peavey driver towards the inside on each side. This is working well with no problems of any kind that we can see or hear.

I installed 1 inch of fiberfill on the back of the interior chambers behind each woofer on the left cabinet.  The right cabinet was left with no damping to see what is better.  Interestingly, most people choose the cabinet with no stuffing because of the added presence it has.  For outdoor use I would recommend it that way.  I like the smoother response of the stuffed cabinet and recommend that for indoor use.  I was pleased to find that the shape of the chambers behind each woofer were not creating any standing waves that hurt the sound.  

Steve  :)
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Re: Hell, those aren't big !
Reply #74 - 01/11/03 at 23:49:50
 
So as you might have guessed we are now listening to a matched pair of cabinets (each with miss-matched woofers).  I still do not have my compression drivers because the original ones I ordered only went up to 9K.  I am now waiting for another pair of something else that will handle between 1.5 ~ 20KHz.  In the meanwhile I have a pair of low grade compression drivers installed using a simple capacitor for a crossover.  The woofers are running in parallel with no crossovers.

The overall frequency balance at this stage is surprisingly flat.  I was also pleased to find out that when you toe them in and stand in the sweet spot you actually get one hell of a sound stage!  Very believable imaging too.  I am very pleased with the bent wood horns and learned something very important as a result of building them.  I will make plans and a white paper available soon where I will try to explain what I discovered about horn flare design.

So for the past week we've just been playing with them.  In this state, they work for any purpose.  PA use, no problem.  Home audiophile use, no problem.

To date, these are the tightest most extended speakers I have heard at any price and any size, including live concerts.  Turning these speakers up loud is an experience you'll never forget.  There is no ear fatigue, and it sounds convincingly live on any type of music.  The effortlessness and shear power is unreal.  I can only compare them to my Acoustats which I listened to last night.  The Imperials sound lower and hit harder and sound tighter in the bass than the Acoustats which should be impossible.  On everything else, they demonstrate a presence that is not found on the Acoustats.  The richness and harmonic textures of piano, string bass, etc. sound more real on the Imperials.  This is because the cabinet is like a piano and you sense it's presence when it plays because it is really there.  On these speakers it is really there too, the mass and size is the same.  Interesting stuff to say the least.

I have never been a person to listen to music loud because my distortion alarm always goes off about half way there.  On these speakers it has not gone off yet, and I'm sure we have listened in excess of 120 dB from time to time.  My ears have yet to ring from listening to these, yet at lower volumes our own band has created the dreaded ringing you hear when you go to bed later that night.  That means ringing is not tied to SPL, but rather a side effect of distortions.

I have just about completed the blueprint for the Imperial.  I plan to give it away for free to everyone following this thread.  Later they will be available on the site for sale.
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Albert
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Re: Hell, those aren't big !
Reply #75 - 01/12/03 at 00:09:37
 
"I plan to give it away for free to everyone following this thread"

pant, pant...drool, drool.......my saw is warmed up and ready to go!
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EZ_Angus
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Re: Hell, those aren't big !
Reply #76 - 01/12/03 at 00:40:26
 

In that case, I'd like to go on record as saying that I AM FOLLOWING THIS THREAD!!!!!


EZ
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Corpsdriver
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Re: Hell, those aren't big !
Reply #77 - 01/12/03 at 02:22:13
 
ok, i am ready to buy the plans... i may overdraw my account,  but i feel these are worth it! Anyone in the market for a pair of a/d/s L1590's? i need to finance a pair of Decware Crown Imperials!
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Brian
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Re: Hell, those aren't big !
Reply #78 - 01/12/03 at 02:42:21
 
I would like to add that not only do You report that they sound great, but they look beautiful too.  I can not remember a more pleasant looking speaker.   Cheesy
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Re: Hell, those aren't big !
Reply #79 - 01/12/03 at 03:29:03
 
Had an interesting revelation this evening while sitting in the shop listening to the Imperials. A new audio term that I will call "transient balance".  While I was listening tonight and pondering the contrasts between what I was hearing from the Imperials and what I would be hearing from a conventional pair of audiophile speakers, I realized something.  

One of the many reasons why conventional audiophile speakers could never sound like this is because the transient balance of regular speakers changes from driver to driver - from woofer to tweeter.  It also changes between the bass and midrange frequencies of a single conventional woofer.  This is what lets your mind know that you are listening to speakers rather than the real thing.  I mean let's face it, if your stereo actually sounded real your mind would short circuit and you would be struck with fear - not unlike seeing a real ghost.  

Anyway, these speakers seem to have a transient signature that is in tact across the entire frequency band.   Besides the Acoustats, I have never heard a speaker that did.  And even though the Acoustats are technically superior on paper, the horns have velocity in the bass and dynamics that even the acoustats could only dream about.  

Transient balance is a definition of transient response across the frequency balance of a loudspeaker.  Regular speakers have wavering transient balance that usually declines with frequency.

All of this is frankly a surprise to both Paul and myself.  Even though this is the 6th time we've built Imperials, they were all by the original plans and with a single driver.  And they were good, but warmer and slower.

Remember, or FYI, back in the 1980's Paul made me build a pair of these so his wife wouldn't see him making them.  I guess he thought he could hide them in his garage.  I agreed and after finishing the first cabinet I robbed a 10 inch woofer from a pioneer bookshelf speaker and stuck it in the cabinet to see what would happen.  The bass response I heard come out of that single 10 inch woofer was so mind blowing that I made a decision right there and then to devote all my attention to audio, the reason DECWARE actually came to be.  I heard two identical speakers, one in the bookshelf cabinet and one in the Imperial and could barely grasp the difference.  It taught me in no uncertain terms that there WAS magic in audio and I wanted more of it!

Cheers

Steve
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thedude
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Re: Hell, those aren't big !
Reply #80 - 01/12/03 at 03:50:31
 
i always knew there was a magic troll in my subwoofer box, the more i cranked the amp up, the more the electricity shocked him and the harder he punched that woofer Shocked, of course the imperials are a lot bigger then my subwoofer, hell you could prob get a pair of lord of the rings cave trolls in each one Grin, now...how can i shoehorn two into my dormroom when i go back to school 8)  -Matt
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #81 - 01/12/03 at 05:10:02
 
>I have never been a person to listen to music loud because my distortion alarm always goes off about half way there.  On these speakers it has not gone off yet, and I'm sure we have listened in excess of 120 dB from time to time.  My ears have yet to ring from listening to these, yet at lower volumes our own band has created the dreaded ringing you hear when you go to bed later that night.  That means ringing is not tied to SPL, but rather a side effect of distortions.<

If you recall, a while back I mentioned having read an article about evidence suggesting that one could listen at much higher levels to sound that sounded good without damaging ones ears. It had to do with the ears being relaxed because you are enjoying what you are listening to. Any distortion would cause discomfort, and cause the eardrum and such to tighten up, and you have listener fatigue soon followed by ringing, and eventually, damage.
I don't think anyone took it serious at the time. Wink


On another topic:
>I heard two identical speakers, one in the bookshelf cabinet and one in the Imperial and could barely grasp the difference.<

I have had similar experiences. The 10 inch drivers I have now sound far more alive in the TQWP cabnets then the one fourth the size bass reflex boxes they came out of. The origional boxes are well built and seem to be tuned correct for the speakers. The bass from the TQWP's is just much more alive sounding. Makes me wonder why anyone would want a small bass reflex speaker anymore.
Dave Smiley  


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« Last Edit: 01/12/03 at 05:11:26 by hurdy_gurdyman »  
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Eli Duttman
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Re: Hell, those aren't big !
Reply #82 - 01/12/03 at 08:11:12
 
>Makes me wonder why anyone would want a small bass reflex speaker anymore.<

When you are a space challenged NYC apartment dweller as I am, small bass reflex speakers are attractive because they fit into the limited space available.  Necessity being the mother of all invention, I've been forced to acquire some expertise in subwoofer/satellite speaker setups.
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Terry
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Re: Hell, those aren't big !
Reply #83 - 01/12/03 at 09:13:16
 
Steve,

What you call "transient balance", I call "linear dynamic tracking", I think we are speaking to the same thing.  Meaning that the entire speaker can product the same level of dyanamics at all frequencies equally particularly how this relates to the speed of each driver.

My ideas of how to go about achieving this are a little different, so I am very interested in what you come up with in the end.  I am thinking of having a compression driver that extends as low as possible, below 500Hz, and a front horn loaded 15" woofer below that.

I like your idea of mismatched drivers, having that ability by two 15" drivers in each speaker is a real plus.  Often I feel it is not the tecnology that is flawed often, but how it is implimented.

I think with your offer we will have more people following this thread now.  I can't wait to see what the total size of these speakers is, so that I can see if I have enough room for them to try out.

TG Grin
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Brian
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Re: Hell, those aren't big !
Reply #84 - 01/12/03 at 10:11:05
 
You know Steve, I have been looking at photos of Your listening room... are You going to have room for dual Imperials in there?  
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #85 - 01/12/03 at 14:58:25
 
My Dad is no longer using his barn. Perhaps I should build these and turn the barn into a suitable listening room. The haymow, with arched roof, is part of a smallish barn, but still way bigger then a typical living room. What a place for parties!
Dave Grin
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Terry
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Re: Hell, those aren't big !
Reply #86 - 01/12/03 at 16:24:22
 

Eli,

With some very desirable drivers folded Voight Pipes are a real option as well, only they have better quality bass.  Have you thought of trying some?  What are you running for speakers right now?

Terry
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« Last Edit: 01/12/03 at 16:25:48 by Terry »  
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Eli Duttman
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Re: Hell, those aren't big !
Reply #87 - 01/12/03 at 17:12:19
 
Terry,

Folded or not, TQWP enclosures are floor standing.  The interaction with the floor is an important part of TQWP bass performance.  A pair of floor standing speakers in my MULTI-purpose living room is out, as there simply is no room.

I have 2 pairs of small bookshelf speakers that get exchanged.  The 1st pair are 1st generation ProAc Tablettes that Mr. Deckert did a MAJOR overhaul on a while back.  The bass performance of the Tablettes is remarkable considering that the cabinet volume is about 1/3 ft.3.  I power the ProAcs with either my H/K Citation II or my AVA FET-Valve.  The efficiency of the Tablettes is TOO low for them to be a good match for a ZEN amp.  The 2nd pair of speakers are my own design that use 94 dB. efficient (nominal) drivers in a 0.55 ft.3 enclosure. The main driver runs full range.  A 2.2 muF. capacitor keeps low frequency information out of the tweeter.  FWIW, the simulation plot for the main driver and 56 Hz. vented enclosure combination is flat within 1 dB. down to 50 Hz.  I use the "homebrew" speakers with my SE84Bs.
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peteM
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Re: Hell, those aren't big !
Reply #88 - 01/12/03 at 17:15:43
 
come back from a holiday and find this thread -- took over an hour to read it all -- gob smacked over the pictures -- beeyootiful speakers. okay --- plans for a music room on hold -- to absorb size of horns. looks like i now have a dream!!!! to fulfil.
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homeyhomes
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Re: Hell, those aren't big !
Reply #89 - 01/12/03 at 17:52:38
 
STEVE,

Do the Imperials sound best when close to the wall  ?
I think most would not want them out from the wall
as they are pretty hefty.

What do You think the overall Speaker Impedance
will be when all said and done ?

4 ohms would probably make the most sense, as
this would work well with ALL the Zen amps.
Of course with the very high sensitivity this probably
isn't a large concern.

Homey

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Re: Hell, those aren't big !
Reply #90 - 01/12/03 at 19:31:57
 
Brian,

Not a chance.  They'll just have to stay where they are.  

Dave,

The Barn idea is great.

Homey,

The the bass will certainly couple much better close to the wall.  That is the way we expect most people to use them.  Even against the wall, they are still 28 inches out into the room.  The impedance will be 4 ohms in most cases.  However, in a smaller room I would like to try two 4 ohm woofers in series and let the natural 15 degree phase shift that occurs create some magic - it usually does.

Terry,

The overall size is around 65 inches high, 38 inches wide and 28 inches deep.  In case of tornado, I would take shelter in the speaker since It's so heavy and can easily support the weight of a house.

Cheers, Steve
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mikes
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Re: Hell, those aren't big !
Reply #91 - 01/13/03 at 16:24:24
 
Steve,

Glad to hear you will make the modified Imperial + horn lens plans & white paper available to us.  I've been using an inexpensive Alpha12 Eminence PA driver (low ZMAX) and cheap HF horn with my Zen for many months now and continue to be impressed with the BANG I'm getting for the BUCK, even though I haven't given the LF driver a chance to show its stuff in a huge cab like the Imperials.  How interesting that we're talking about such 'old' technology and how good it can sound...

Peace,
MikeS
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« Last Edit: 01/13/03 at 16:43:59 by mikes »  
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Corpsdriver
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Re: Hell, those aren't big !
Reply #92 - 01/13/03 at 21:26:18
 
I just sent the url for this thread to my audio company partner, (he also helped my build my HWK) He says he can hardly wait to sink his saw teeth into this project! He wants to make the bentwood lenses too, but i have a 3' pair of vintage JBL 2" lenses already... i wont argue with him. Looks like i may need to buy a new AB Precedent amp... some Altec, or JBL compression drivers... (dreaming)

Jamie
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Jim
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Re: Hell, those aren't big !
Reply #93 - 01/13/03 at 22:51:35
 
This project is really interesting, I just can't convince myself that 2 speakers that would be OVER 6 FEET wide would work very well in my listening room with it's 10 foot wall!

I think it would really convince my friends (not to mention wife) that I'd finally lost it.

Happy Listening,
Jim
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #94 - 01/13/03 at 22:55:25
 
>I think it would really convince my friends (not to mention wife) that I'd finally lost it.<

My wife and family and friends are already convinced that I've lost it!
Dave Grin

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Corpsdriver
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Re: Hell, those aren't big !
Reply #95 - 01/13/03 at 23:03:24
 
I never had it to lose in the first place... i did rent some of "it" for a few days... then i left it somewhere... i hope someone gave it a good home.

Jamie
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steve_f
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Re: Hell, those aren't big !
Reply #96 - 01/14/03 at 02:53:20
 
Hi Everyone,
Like Steve and a few of the other members,  I'm simply amazed at how much different a driver can sound in different cabinets.  I can't wait to try building the Decware Imperials!  
There really is magic in a good horn design. Steve, it sure sounds like you found some!
Take care,
Steve F
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Terry
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Re: Hell, those aren't big !
Reply #97 - 01/14/03 at 07:59:22
 
Steve,

Have you ever thought of trying the JBL 2226G's in this cabinet.  I would think they would work well, sound good, and be a good match for a Zen SE84CS with their 4 ohm impedence.  I recently heard these and have been very impressed with them for a high efficiency driver.  They have a fairly smooth frequency response as well, with nice bass extention.

TG Grin
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MagMan
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Re: Hell, those aren't big !
Reply #98 - 01/15/03 at 00:53:50
 
Funny you should mention the JBL 2226's I just got a pair but now that Steve is going to hook us up with the plans (THANK YOU STEVE!) I am going to have to get another pair. The old Fraizer wood horns I got off E-Bay showed up. I installed the drivers (sounds like the same ones Steve had) and used the EV st350 tweeter and some old EV Sentry 4 crossovers I had using my Ohm Walsh 4's just for low end. (I know, don't say it I just wanted to hear the horns) THe 4's need to go now so it looks like they are E-bay bound. I already have a spot for the Imperial's
Mike
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Steve Deckert
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Re: Hell, those aren't big !
Reply #99 - 01/15/03 at 03:50:07
 
UPDATE

9:17 pm.  I'm beat.  The bed is calling... back hurts, thinking about skipping the nighty ritual of sitting out in the shop listening to the jazz station on the radio (with the Imperials).  9:41 pm. Oh what the hell...  9:51 p.m. I sit there in my chair staring at the bent wood horns thinking I really should at least varnish the other one so they match.  10:00 p.m. Standing on my tip toes varnishing the insides of the horns - while listening to them of course.  

(Every now and then the audio Gods decide you need to know something and give you the strong spontaneous urge to do something they know will cause a chain of events that allows them to teach you something.  You always know if the discovery was your own, or if it was an intentional lesson by the sudden spontaneity of it.)

The most amazing thing happened while I was varnishing.  As I applied the varnish, while it was still shiny and laying on top of the surface, the sound would come out of the varnish!  Just a 6 inch square area in the throat raised the presence by 3dB. It was unmistakable, yet I couldn't believe it.  Before you know it, I was varnishing like a mad man trying to get the whole inside of the horn wet before it would tack up because as soon as it tacked up the effect went away.

My overwhelming gut feeling is that there is more to it than just the difference between the shiny or rough surface.  The sound was magic.  These horns are working so well it's really amazing me.  The dispersion is simply incredible.  Absolutely NO beam even at a distance of 1 foot away.  In any case having a glass smooth finish inside THIS horn raises the output by several dB and widens the dispersion angle by a very noticeable amount.  Having a wet finish, like liquid, creates the magic as the surface tension between the air and liquid apparently isolate the wave front from the resonance of the horn walls - improving coherency.  Oh God, I'm starting to sound like Terry.  :-/
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Terry
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Re: Hell, those aren't big !
Reply #100 - 01/15/03 at 04:25:10
 
I'm flattered  :o



P.S. I am in desparate need of photo's Steve, otherwise I am affraid my enthusiasm will diminish Embarrassed   Can you post one of how you mounted the driver to the horn?
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« Last Edit: 01/15/03 at 04:27:57 by Terry »  
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thedude
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Re: Hell, those aren't big !
Reply #101 - 01/15/03 at 06:11:13
 
hmmmm, im thinking horn tweeks now, wax, crisco, jelly... Grin
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John_M
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Re: Hell, those aren't big !
Reply #102 - 01/15/03 at 12:25:12
 

[quote author=thedude  link=1040842968&amp/90#101 date=1042611073]
hmmmm, im thinking horn tweeks now, wax, crisco, jelly... Grin
[/quote]

Would that be surfboard wax for that "California sound", or "Olde English Furniture Polish" fo that laid-back British sound?  :o Shocked Shocked

The mis-matched driver discussion reminds me of an experience in my early stages of Audiophilia Nervosa:  I was in one the local "Stereo Super Stores" (that was actually it's NAME!) listening to the then top of the line Polk speakers.  They were gigantic pseudo-planar speakers 4'x6' covered with 4" drivers.  I was A-B testing them with Polk's second from the top speakers (slightly smaller but same basic configuration) and neither one sounded particularly astounding.  Funny thing was, when I had both sets playing the tonal quality took a huge jump up.  It seemed the uneven interaction of the different drivers produced something closer to "real" than all the matched sets.

Perhaps the brain knows that sounds from natural sources are essentially unevenly spread across the device producing them.  Most of the sound from a guitar comes from the sound box, but there are still discernable sounds coming from the strings on the neck.  The sound waves of a piano are spread across a finite distance within the instrument, those waves resonate from the body of the piano with different nodes and they also bounce off of, and resonate with, the lid.

The human ear (and the brain that process the information) is very spatially sensitve.  I suggest that this sensitivity and the processing that goes along with it are what's responsible for our perception of a "real" instrument.  Perhaps the mis-matched drivers in the Imperials (I bet you were wondering when I'd get back to that!  ;) ) helps simulate the physical size of an instrument BECAUSE of the different sonic qualities of those drivers.
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John_M
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Re: Hell, those aren't big !
Reply #103 - 01/15/03 at 12:47:00
 
Continued...

This argument could also lend support to the debate on microphone placement: close or far.  Close micing generally exludes the parts of the instrument that are farthest away from the mic.  A mic that is farther away will capture most or all of the sounds coming from the instrument, but without the emphasis of one source over any other.  Hopefully the artist is getting what they want from what's being recorded or broadcast.

In the end it doesn't suprise me that mismatched drivers lend a more natural sound in this design.  Maybe Steve should PLAN on having 2 different drivers in the final design, if that's what sounds best!

Got a question about those wood lenses.  When you notched the back of the plywood to allow for the bend did you cut through all but the last layer of ply?  It sure looks like it from the pictues!  Is plywood usually consistent enough or did you have to make a couple goes at it to get it just right?
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #104 - 01/15/03 at 12:53:38
 
>This argument could also lend support to the debate on microphone placement: close or far.  Close micing generally exludes the parts of the instrument that are farthest away from the mic.  A mic that is farther away will capture most or all of the sounds coming from the instrument, but without the emphasis of one source over any other.<

I am a big fan of Distant micing. Acoustic instruments just sound more natural when the mic is a ways off.
Dave Smiley
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Terry
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Re: Hell, those aren't big !
Reply #105 - 01/15/03 at 14:07:46
 
How far you mic an instrument, and how it sounds on play back I feel depends on the play back system.  The better the playback system the better distant mic-ing sounds, but on low fi stuff close micing sounds much better.  Don't even think of asking my why, but I know it is true.  When I go to listen something, I always take a recording that I know most of the instruments are recorded from a distance.  Piano and drums especially take on a spacial property.  Most would feel these are not as good of recordings, but on a good systems they blow all that close mic'd stuff away.  Of course the type of mic used makes a large difference in all of this as well.

TG Grin
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earwax
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Re: Hell, those aren't big !
Reply #106 - 01/16/03 at 03:54:08
 
There is in fact a quantifiable explanation for what you experienced Stevie. It lies somewhere within the realms of fluid dynamics, I remember something similiar(vaguely) about compressible fluid flows and Reynolds numbers, viscosity, surface tension and laminar and turbulent gas flows at subsonic and supersonic speeds through a pipe to a receiver with a proper transducer, enhanced with psychotropic conditioning agents. But, other than that, I can't really say anymore about it.
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Re: Hell, those aren't big !
Reply #107 - 01/16/03 at 04:01:33
 
Wax, that is a little over simplified but we will let you slide this time.
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Brian
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Re: Hell, those aren't big !
Reply #108 - 01/16/03 at 08:22:56
 
I do not think the friction approach is the right answer because the music is carried in the sound pressure waves traveling down the pipe not in the rush of air which is what would be dragged by a less slick surface.  

Perhaps the resonant sound in the wood can more readily move into the air through a solid to liquid to gas transformation than by trying to go directly from a solid to the much more rarified gas.  

[I have always wanted to use one of those "lamp of ingenuity" icons]
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earwax
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Re: Hell, those aren't big !
Reply #109 - 01/17/03 at 04:42:31
 
Oh, it's the old resonance magnifaction through a multi-phasic conductance medium theorem, is it. This argument does have some merit, as it is well known. If the forcing frequency is equal to the natural frequency the magnifacation factor can be quite large. But the fundamental is still a coefficient of viscous damping and is not the same as the natural frequency, this of course is a result free vibrations. On the other hand, it's possible the oscillations could be under-damped which of course means there will be a diminishing amplitude of the sound wave at that locus and therefore the resultant noted increase is the result of psycho-acoustic aromatic hydra-tetra-cannibinols that the government has surreptitiously added to the varnish. In any event it's still fluid dynamics..."a less slick surface!!!" They just don't teach techno-babble like they used to..Sigh.
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« Last Edit: 01/17/03 at 04:45:19 by earwax »  
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #110 - 01/17/03 at 04:47:58
 
??? ??? ???
Ah, could you translate that for dummies, please? Or maybe it's just to late in the night, err..., early in the morning for my brain to kick in.
Dave Undecided
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earwax
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Re: Hell, those aren't big !
Reply #111 - 01/17/03 at 04:53:47
 
Trust me David, I know my vibrator's and fluid dynamics.
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earwax
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Re: Hell, those aren't big !
Reply #112 - 01/17/03 at 04:55:53
 
I mean, vibrations and fluid dynamics.
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Albert
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Re: Hell, those aren't big !
Reply #113 - 01/17/03 at 14:54:50
 
Let's try and keep things clean Wax...thanks
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Corpsdriver
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Re: Hell, those aren't big !
Reply #114 - 01/17/03 at 15:05:44
 
What wax was trying to say Dave, is that Steve was stoned on varnish fumes...

Jamie
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #115 - 01/17/03 at 16:44:30
 
There for a minute I thought Ms Wax may have inhaled a bit too much fumes as well. Tongue
Dave Grin
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Audioillusion
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Re: Hell, those aren't big !
Reply #116 - 01/18/03 at 00:55:32
 
[quote author=Terry  link=1040842968&amp/105#105 date=1042639666]
Piano and drums especially take on a spacial property.
[/quote]

I definately agree!

What pains me the most, if they will close mic an instrument and then add reverb and all kinds of filters to add the illusion of "space" to the recording, when they could actually use the acoustics of the room to create the same effect, only in a more realistic sound.

Also, I'm not sure about this one...

Doesn't micing at a distance increase the dynamics of the mic, by not stressing the mic.
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Corpsdriver
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Re: Hell, those aren't big !
Reply #117 - 01/18/03 at 02:33:47
 
didnt i mention something about mic tecniques and dumping in digital bullthingy ages ago?

Jamie
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Audioillusion
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Re: Hell, those aren't big !
Reply #118 - 01/18/03 at 04:06:12
 
HAHAHA, I didn't have time to read earwaxes post. Very amusing. Yeah, lets keep in "mind" that our passion for hi-fi is driven by 'illusions' which are sometimes exagerated by chemical influence. Cheesy
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Re: Hell, those aren't big !
Reply #119 - 01/18/03 at 04:34:46
 

[quote author=John_M  link=1040842968&amp/90#103 date=1042634820]

In the end it doesn't suprise me that mismatched drivers lend a more natural sound in this design.  Maybe Steve should PLAN on having 2 different drivers in the final design, if that's what sounds best!

Got a question about those wood lenses.  When you notched the back of the plywood to allow for the bend did you cut through all but the last layer of ply?  It sure looks like it from the pictues!  Is plywood usually consistent enough or did you have to make a couple goes at it to get it just right?
[/quote]

I do plan to have two different drivers in the final design.  It is just working way to well.  It makes it possible to keep this a two-way design.  

As for the wood horns, yes, I cut to the last layer.  The two I built were the first trys.  They are not perfect.  However I know now how to design the jig to make it less painful to build.






Here is a picture of the new 15 inch drivers I got.  I'll take a pic this weekend of the cabinets with the drivers installed.
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Terry
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Re: Hell, those aren't big !
Reply #120 - 01/18/03 at 06:07:56
 

Awe come on Steve! Your killin us, what are those drivers.  What brand, what specs, what use in the cabinets.  This teasing has got to stop, now I only want to see more pictures.  I wanta see the wood horns!  Please pics of the wood horns.

TG Grin
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John_M
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Re: Hell, those aren't big !
Reply #121 - 01/18/03 at 11:33:22
 

[quote author=Steve Deckert  link=1040842968&amp/105#119 date=1042864486]

Here is a picture of the new 15 inch drivers I got. .

[/quote]

OOOOHHHHHH!!!!  Pretty!
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Audioillusion
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Re: Hell, those aren't big !
Reply #122 - 01/18/03 at 16:50:58
 
They look like JBL's.
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steve_f
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Re: Hell, those aren't big !
Reply #123 - 01/18/03 at 20:09:03
 
Could be JBL, Beyma, P audio.

I'm curious too!

Steve F
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Re: Hell, those aren't big !
Reply #124 - 01/18/03 at 23:45:51
 
The woofers are essentially JBL clones made in China and distributed by a European company called Goldwood Sound.  

http://www.gold-wood.com/

I am very impressed so far.  I needed something that was half-way efficient and something that would at least hit 30 Hz.  They are super smooth, and roll off fast so there is no midrange.
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Re: Hell, those aren't big !
Reply #125 - 01/19/03 at 15:32:45
 
Ok Steve did you pick this speaker outfit because of their cosmic intro graphics?  ;D

I did not see any usable specs on the 15 though. Do they provide TSP's on their pro drivers?
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John_M
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Re: Hell, those aren't big !
Reply #126 - 01/21/03 at 19:17:23
 
This is so cool!

I was showing the pictures of the Decware Imperial Folded Horn to my wife last night and she said "that looks nice, I wouldn't mind that in my home."  Is that great or what?  The Imperials have high WAF!

I am a lucky man! Grin Grin Grin Grin Grin Grin

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thedude
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Re: Hell, those aren't big !
Reply #127 - 01/22/03 at 15:03:16
 
thats great John Smiley, did you cover up the background to make them look smaller Tongue, i dotn have the waf to deal with yet, not gonna get married til i meet a woman who approves of this hobby, and i figure if i build a pair before i get married, she wont make me get rid of them, speaking of which, how are those blueprints coming Steve? -Matt
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Corpsdriver
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Re: Hell, those aren't big !
Reply #128 - 01/22/03 at 15:14:40
 
I am pretty lucky too! I have WAF appoval for anything i do in my basement, so that means most of my speakers will go up for sale when i build my imperials. She is NOT gonna let me lug my existing speakers upstairs to the bedroom...

http://home.attbi.com/~corpsdriver/wsb/html/view.cgi-home.html-.html

Jamie
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Brian
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Re: Hell, those aren't big !
Reply #129 - 01/23/03 at 19:28:43
 
Steve, have You played Your new push pull amp through Your new Imperial speakers?  How do you like the signature combination?  
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homeyhomes
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Re: Hell, those aren't big !
Reply #130 - 01/24/03 at 04:47:24
 
I am thinking about building a pair of Imperials
since I have access to 3 different cabinet shops.
(use of the equipment + discounted prices on lumber) Smiley

3/4" Birch Ply seems to be very popular for speaker cabs.

Has anybody had experience with staining Birch Ply?
I know some Plywoods just do not look good stained.
Veneers look like they wood be very tough to do on a
Speaker like the Imperials. And Painting them would be
an injustice.

homey
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Terry
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Re: Hell, those aren't big !
Reply #131 - 01/24/03 at 05:09:51
 

Oh do I ever have experience staining burch plywood, learned the hard way you need to use a pre-stain, this way you get an even coating and avoid any blochy spots.  This is my one tip for birch plywood.

TG Grin
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #132 - 01/24/03 at 12:46:28
 
You can stain birch ply the normal way, but it takes a LOT of fine sanding, and sanding, and sanding. When you get it very smooth, the results can be very good. I like the large contrast in the grain. However, if you have areas that are not quite as smooth as other areas, it will blotch.
Here's my boxes made of birch ply (scroll down to just over half way down).

http://home.fuse.net/randyr/AudioFest6.html

Dave Smiley
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« Last Edit: 01/24/03 at 12:49:00 by hurdy_gurdyman »  
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Bob J
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Re: Hell, those aren't big !
Reply #133 - 01/24/03 at 18:57:26
 
I wonder if a dye stain would be better than the pigment based Minwax products. I made the mistake of using Minwax on the Poplar (solid wood) I used on my Hedlunds. Lets just say, I will be painting the wood parts for sure.  ;D
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« Last Edit: 01/24/03 at 18:58:03 by Bob_J »  
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Terry
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Re: Hell, those aren't big !
Reply #134 - 01/24/03 at 20:17:12
 

Bob,

Do you have pics of you Helunds on the net so that we can gaze in awe?  I thought I sanded real well, and I still got blotchy areas.  Pre-stained helped a lot, another thing I don't like is that most plywood looks like plywood stained, it has a different grain that regular wood.  I like using vineer, it is easy looks nice, and doesn't require a bunch of tools.  you can sand the edges off, that works as good as a router in my opinion, a orbital is better but I have hand sanded before.  Laminet is harder because it is thicker and harder than wood vineer.

Oops! we have hijacked Steves thread.  Sorry Steve.  We should start a thread on the speaker building forum, although this got started by how to finish the Imperial cabinets.  I think putting vineer on them would cost a mint, I wouldn't, and I would use a plywood like Steve used a lighter weight wood, as light as I could get.

TG Grin
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« Last Edit: 01/24/03 at 20:20:05 by Terry »  
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Albert
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Re: Hell, those aren't big !
Reply #135 - 01/24/03 at 21:33:17
 
Use 3/4 inch white Melamine particla board for that stark look, and the melamine is bullet proof for little hands that like to use finger paints on your cabinets.
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Re: Hell, those aren't big !
Reply #136 - 01/25/03 at 01:52:58
 


As far as finishes go, one thing I've thought about is wrapping it with the same vinyl as the guitar amp in the background of this photo.  Probably won't do anything until Spring in the way of finishes.

Here is a small pic of the left cabinet with new drivers installed.  The one on the right is a Peavy Scorpion.



I'm going to start posting about the horns here with pics here shortly.

Cheers,

Steve
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Re: Hell, those aren't big !
Reply #137 - 01/25/03 at 02:05:15
 
Design notes: Jan 2003 - New Imperials

As usual the batteries in my camera are dead so pictures will be forthcoming.  I wanted to take a few shots of the bent wood horn.  I'm still experimenting with it.  At the present time I have a different compression driver in each cabinet.  The one on the right is an audiophile grade unit that goes up to 20K.  The one on the left, is the Selenium that only goes out to 9K, but can be used down to 600 Hz.  

I ended up leaving the left hand one in all this time because it actually sounds much better even though it lacks the top octave. Naturally I've decided the tone and timbre of the left side is something I can't live without but I've got to get more extension in the top.  

Last week I discovered a significant rise in efficiency as I was varnishing the inside of the horn flare.  This improved the situation somewhat with the left compression driver, but it will still have to either be replaced or supplemented with a super tweeter, something I hate to do.

Right now there is a natural balance of current between the three drivers in the cabinet and virtually no crossovers other then a single cap on the compression driver.  Adding another component will probably break the synergy.

Terry and others have been waiting to see details on how the compression drivers are mounted onto these bent wood horns but at this point it's too early to say.  My original idea, which I did, was to use a 3/4 board with a 1-3/8 hole threaded for the driver and mount it directly on the back of the lens.  I used plywood at the time and it proved impossible to thread properly.  Knowing I would have to resort to hardwood, and purchase a 1-3/8 fine thread tap I decided to cost of the tools may be less than ideal for the people planning to build a pair of these.  To cover all the bases I decided to purchase some plastic horn lenses from a surplus catalog and cut the threaded flange off and simply glue it to the back of the bent wood horn.  This is $5.00 verses the price of an expensive tap.  

Tonight I re-installed the left compression driver by using part of a plastic lens as mentioned above.  I cut the lens about 1.5 inches past the threaded collar because the square shape of the plastic lens matched perfectly with the square 1 x 1 inch opening in the back of the bent wood horn.  I knew that the plastic in this high pressure area of the horn would raise the efficiency a bit, and should be technically superior to the original method of mounting the driver directly on the wood.  

Interesting results.  The horn did indeed pick up more efficiency.  In fact with the varnish and now the plastic part, the sensitivity is now almost in danger of needing attenuation.  

Listening test - prior to tonight, the horn on the left always had better tone then the horn on the right.  Now with the plastic piece the entire speaker on the right hand side sounds better then the left.  Prior to this the speaker on the left always sounded better because it has a calculated amounted of stuffing behind the woofers whereas the cabinet on the right does not.

The sound that is coming from the left horn is now unlistenable.  It has that famous "horn" sound that makes you think your at a small live concert with a crappie sound man.  I was surprised that it only took 1.5 inches of plastic to ruin the sound.  Prior to this the horns sounded anything but like a horn, in fact I've been flirting with the idea of replacing my acustats with these speakers - in part because the highs are so good, open, free of any coloration, and non-beaming.

The conclusion is that the high pressure zone directly in front of the diaphragm is full of stress that is compounded by the first couple inches of the lens.  All lenses are smooth, especially there.  Controlled pressure release with pin holes, or specific dampening in the critical area of a horn determines the signature of the horn and effects every other aspect of its parameters.  In the original method using a 3/4 board with the hole drilled in it so that the driver could screw in, the end grain of the plywood that was left because I couldn't thread the driver all the way in.  The end grain absorbed the stress.  

Next step is to restore the original driver mounting and loose the plastic piece.  I knew from past experience that this was the most critical area of building a wood horn lens.  I did not realize however what caused most commercial horn lenses to sound like PA systems until tonight.  My conclusion is that if it is plastic, metal, fiberglass and does not trade a few dB with some carefully designed stress relief at the throat, it will sound like a horn.  My bent wood horns do not sound like a horn, the sound like and in fact better than my electrostats.  This is proof that the "horn" sound is really a byproduct of poor design.
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Re: Hell, those aren't big !
Reply #138 - 01/25/03 at 02:34:16
 
A follow up to the above post:

I left the 1-1/2 inch plastic horn piece fixed to the back of my bent wood horn all week.  Each night when I go out in the shop I tried to listen to it.  Never made it past 4 minutes during any one night.  It is amazing how it has ruined the sound of the entire speaker.  

I have pondered the GIANT change in sound all week.  I have to admit that when I first hooked up the bent wood horns and listened (with the driver screwed into the wood) I was a little surprised that it had ZERO "horn" sound.  And also amazed at the absence of a beam and complete lack of peaks anywhere in it's response.  Over the past month, I have come to respect them to the point where I'm thinking they're better than my electrostatics.  Then my little mod with the plastic threaded extension and what I am hearing is the definition of the "horn" sound multiplied by at least four!

I realized that it is also the fact that the plastic throat is too close to parallel for proper wave expansion and is so on both the horizontal and the vertical.  To hear what this does to sound, just make a 10 inch diameter tube from poster board and tape it to the front of the woofer on your loudspeaker.  What you hear is a few octaves lower than a compression driver obviously, but the signature is the same.

I studied the plastic throat carefully and realized that most inexpensive horn lens are made this way, and that is where the "horn" signature got it's reputation.  Then I pondered why?  Surely they can't be this stupid...  oh, perhaps it's because it develops about a 10 dB peak at 800 Hz and gives the illusion that it's kicking some real ass when in fact it's not.

Anyway, it was an epiphany for me, I gained a deeper understanding of how critical the first 1 to 3 inches of the throat is and now understand why the bent wood horns originally sounded like QUAD electrostatics rather than like compression drivers.  Now I know how to make sure they stay that way.  I also realized that many people might make a lens similar to these and conclude that they suck because they improperly mated the compression driver to the throat...

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Re: Hell, those aren't big !
Reply #139 - 01/25/03 at 02:41:44
 


This is a picture of the "evil" plastic thoat.  To kill the "horn" sound it made, I cut the threaded part off and sanded it until I had a threaded collar.  This way the outlet of the compression driver mates directly with the wood throat.  The 1 x 1 opening is carefully rolled into a dish shape to maintain a smooth transition from the outlet of the driver to the throat of the wood horn.

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Re: Hell, those aren't big !
Reply #140 - 01/25/03 at 02:48:00
 


Here is a pic showing the 3/4 board used to receive the collar as well as hold the back of the horn up.  Setting beside it is the "evil" plastic throat that this system replaces.



Woops, another damn picture... by now I'm sure modem users are well, less then happy!

Steve
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Albert
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Re: Hell, those aren't big !
Reply #141 - 01/25/03 at 02:57:14
 
Hey Steve my Altec 811's and 511's have a slight chamber opening up just after of the beginning of the throat and it is not a casting anomally but actually part of the design. I wonder what this was designed for? Take a gander at the pics and take a shot at it.

http://home.internetcds.com/~adaatdh/511_top.JPG
http://home.internetcds.com/~adaatdh/511_side.JPG

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« Last Edit: 01/25/03 at 02:59:16 by Albert »  
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Brian
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Re: Hell, those aren't big !
Reply #142 - 01/25/03 at 02:59:54
 
This project is fascinating!  
Back on pg 4 Steve, you said: "acoustic bass on this speaker simply wastes Pauls 200 watt CLASS A all tube bass rig - also using 2 15 inch drivers. Imagine that for a minute. Imagine an acoustic bass growling with textured low notes that are tight and powerful enough to make a good sounding electric bass sound stupid. Well, this is what is happening."

This has lead me to wonder, has Paul played his bass amp through the Imperial cabinet?  I guess a road crew would not be willing to lug such a thing around on a tour, but it might be a nice choice set up in a long term installation in a night club where a performer was returning night after night.  
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Re: Hell, those aren't big !
Reply #143 - 01/25/03 at 03:05:52
 
As a DSL user I am very very happy.  I was wondering how it all would fit together.  Steve I can't remember how low can the wood horn go in frequency of hertz?  Is this an exponential or tractrix curve?  This is a interesting learning experience much like some of the things I have gone through.  Where is your crossover point?

TG Grin
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« Last Edit: 01/25/03 at 03:15:56 by Terry »  
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Re: Hell, those aren't big !
Reply #144 - 01/25/03 at 03:45:43
 

[quote author=Albert  link=1040842968&amp/135#141 date=1043463434]
Hey Steve my Altec 811's and 511's have a slight chamber opening up just after of the beginning of the throat and it is not a casting anomally but actually part of the design. I wonder what this was designed for? Take a gander at the pics and take a shot at it.

[/quote]

It rotates the wave front 90 degrees from V to H.

Steve
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chrisb
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Re: Hell, those aren't big !
Reply #145 - 01/25/03 at 03:49:29
 
nice job on the HF horns, Steve - still pulling those slivers out?

the resolution on my monitor's not fine enough to see, did you use kerfcore or timberflex- or table saw the kerfs in solid or ply?

As for finishing birch ply, my own personal tip is seal (wash) coat of solvent based lacquer, sand, spray pigment based stain of choice, followed by  3 -4 spray coats of pre-catalyzed nitro-cellulose lacquer, hand sanding between coats, progressively to 400G.
Better yet, laminate with cherry, walnut, maple, mahogany, beech, almost any quality veneer. Birch can be either really boring, or have tons of patches, poorly matched cathedral patterns, color variations  and mineral stains.

Once fully cured the better of today's lacquers are almost bulletproof, and never need touch-ups for gloss like oils or waxes do.  Of course any finish can be damaged .

Of course you could always go P-lam (which can be harder to work with than veneer, and never as pretty)  Obviously I've got some strong opinions here.


http://homepage.mac.com/tlinespeakers/TLS/FALL/images/Hugos-TL-pipes.jpg

http://members.shaw.ca/t-linespeakers/FALL/images/BD-Pipes-FE103A.jpg
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« Last Edit: 01/25/03 at 03:55:52 by chrisb »  
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Re: Hell, those aren't big !
Reply #146 - 01/25/03 at 04:58:41
 
My wife likes the natural wood grain.  Maybe a simple clear urethane?  Hard to tell from the pictures how good that would look. Undecided
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Re: Hell, those aren't big !
Reply #147 - 01/25/03 at 05:31:27
 
Nice looking project. You can also buy an adaptor that has female threads for a screw on driver to a bolt on pattern horn flare. This adaptor could then be mounted directly to your horn throat, eliminating any straight sided throat transition.
If you make a throat you might try a 12-16 degree angle for that short section. The conical throat section will help to eliminate peaking too.

Bill
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Terry
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Re: Hell, those aren't big !
Reply #148 - 01/25/03 at 07:25:00
 
Chris,

Was that vineer you used on your little bypolar VP's?  How do you router it on the 45's at the corners?

Steve,

What you discribed you experienced sound very similar to what I have experienced.  The best speaker I have ever heard was a Sounddesign A-1, a nearly 7' tall by 2.5' wide electrostac pannel.  The times I have heard horns done well, along with Lowthers in the Oris 150 horn, they both sounded similar.  Which to me seems strange.  I guess they have some similarities, one is that both are moving air by means of a diaphragm that is moving moving just milimeters at most.

To me the advantage of the horn is the simplest circuits you can couple it to, SET amplifiers.  This is horn driver thing is becoming more interesting by the moment.  

TG Grin
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« Last Edit: 01/25/03 at 10:17:42 by Terry »  
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Re: Hell, those aren't big !
Reply #149 - 01/25/03 at 15:30:01
 
I have GOT to dig out my lenses, and take some pics to see what you guys think. i want to use them with my "Crown Imperial" project. but new drivers are WAY spendy...

Jamie
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Re: Hell, those aren't big !
Reply #150 - 01/25/03 at 15:58:16
 

[quote author=bmar  link=1040842968&amp/135#147 date=1043472687]
Nice looking project. You can also buy an adaptor that has female threads for a screw on driver to a bolt on pattern horn flare. This adaptor could then be mounted directly to your horn throat, eliminating any straight sided throat transition.
If you make a throat you might try a 12-16 degree angle for that short section. The conical throat section will help to eliminate peaking too.

Bill
[/quote]

I'm not seeing it.  Most adapters I've seen would be no different then the plastic throat I tried.

Steve
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Corpsdriver
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Re: Hell, those aren't big !
Reply #151 - 01/25/03 at 17:55:44
 
here is the link to pics of my lenses, i hope they will work on the imperials...
http://corpsdriver.home.attbi.com/id19.htm

Give me line of credit, I still learning to making web page.

Jamie
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bmar
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Re: Hell, those aren't big !
Reply #152 - 01/25/03 at 19:00:12
 
Steve,

Martin Sound has these. catalogue number 1846, model 9999062
http://www.martinsoundpro.com/PDF_files/adapters.pdf
11.00 each. This is what I was thinking you could use.

Bill
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Steve Deckert
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Re: Hell, those aren't big !
Reply #153 - 01/25/03 at 19:07:16
 
Yep, model 9999062 would be fine, it's just a collar.
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chrisb
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Re: bi-polar pipes
Reply #154 - 01/25/03 at 21:37:12
 
Terry - the veneer is flat sliced cherry, stained with a medium walnut pigment stain (2 coats, washed out with thinners to even out the color and let more grain through - this entirely to personal taste)  3 spray coats of lacquer - hand sanded between.  I generally choose darker stains as it hides the kraft paper backing on the veneer, and I just like the colors.

The chamfers on the edges are simply routed with a 45` bit, and touched up with hand file on the inside corners.

I use the DIY iron-on method for veneering smaller projects like this; progressing from larger panels to smaller. Carefully laying out and numbering the veneer pieces first, you should need very little overlap on the edges, which can easily be trimmed with 2" chisel and sanded flush.  Edges are done the same way, it just takes more time.  Folding the veneer around the 45` corners was an experiment on these pipes that didn't work out quite as I'd hoped.  

Use yellow glue only and buy a cheap clothes iron.  This method takes a little practice, but is much more forgiving than any contact adhesive, and the glue won't be lifted by any finishing products.
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ns
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Re: Hell, those aren't big !
Reply #155 - 01/27/03 at 12:26:54
 
Steve,
Would you ever quit doing this!!!! Now I have to think of where I can put these things (once I build them) Do you have any idea how expensive houses are in Ireland?
I bought a pair of the original radial drivers years ago when Steve was still playing with them because I read his white paper after he built the prototypes. Now I am going to have to get these plans and build these monsters. I guess the only consolation is that there is no hope of doing it anytime too soon. Try as I might, they won't fit into our two bedroomed apartment. Please put me on the list for the plans though as I will build them if it kills me.
Neil.
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MikeS
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Re: Hell, those aren't big !
Reply #156 - 01/27/03 at 16:24:32
 
Bill Martinelli uses an interesting machined "Billet Aluminum throat piece with stainless steel hardware" in his wood horns

http://www.woodhorn.com/woodhorns.htm

I'm wondering if Bill encountered some of the same "evil" sonic throat signatures Steve witnessed before deciding to use these...

MikeS
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Steve Deckert
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Re: Hell, those aren't big !
Reply #157 - 01/28/03 at 00:59:52
 
Okay folks, as promised here are the plans in a .pdf format.  I will be offering them on the site for sale in both an online format (this) and a full blueprint.

The file is located here:

http://www.decware.com/forumtemp/imperial.pdf

the username is: forum
the password is: imperial

This file will remain here for a VERY limited time and then it will be deleted.

Have fun!

Steve  ;D
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nubz69
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Re: Hell, those aren't big !
Reply #158 - 01/28/03 at 02:56:32
 
I've been checking on this thread every once in a while and it is very intresting.  One thing that got me thinking was this -

"I mean let's face it, if your stereo actually sounded real your mind would short circuit and you would be struck with fear - not unlike seeing a real ghost."

at first this made me wonder if this would trigger a fight or flight responce in people.  Then it got me to thinking exactly how much does the mood/state of mind we are in have on the way we perceive sound.  Do you think that that magic we get every so often(for me at least) could be a result of our mood and not exactly the system?
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Brian
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Re: Hell, those aren't big !
Reply #159 - 01/28/03 at 03:19:53
 
Thank you Steve,  I hope I won't take forever to make one of these - or maybe a pair.  
Brian Albin   Smiley
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Terry
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Re: Hell, those aren't big !
Reply #160 - 01/28/03 at 07:06:06
 

I know beggers can't be choosers, but I was really hoping to see something on the wood horns in these plans.  Is that forthcomming?  Thanks for the cabinet plans for the two 15" rear loaded horn cabinet, it is way too cool.  Too bad I had my heart set on the midrange wood horns as well, that was the real candy for me.  Perhaps the details of the throat coupling aren't worked out yet.

The not totally bummed out,
TG Sad
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #161 - 01/28/03 at 12:50:34
 
My ancient computer can't seem to open the link. I've tried everything I can think of.
Dave Cry
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Randy
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Re: Hell, those aren't big !
Reply #162 - 01/28/03 at 13:40:00
 
Howdy Dave,

Do you have the Adobe Acrobat Reader loaded on your "ancient computer" ?  You will need it to open this file.

If you don't have it, you can download the reader from the Adobe Website.

Regards,

Randy
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Albert
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Re: Hell, those aren't big !
Reply #163 - 01/28/03 at 13:46:02
 
Steve, what CAD program do you use? could you provide me with the CAD drawing? I would like to create a 3D model of it if it's ok with you and the CAD info might help.

Thanks
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Randy
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Re: Hell, those aren't big !
Reply #164 - 01/28/03 at 14:12:30
 

[quote author=nubz69  link=1040842968&amp/150#158 date=1043722592]
I've been checking on this thread every once in a while and it is very intresting.  One thing that got me thinking was this -

"I mean let's face it, if your stereo actually sounded real your mind would short circuit and you would be struck with fear - not unlike seeing a real ghost."

at first this made me wonder if this would trigger a fight or flight responce in people.  Then it got me to thinking exactly how much does the mood/state of mind we are in have on the way we perceive sound.  Do you think that that magic we get every so often(for me at least) could be a result of our mood and not exactly the system?
[/quote]

Howdy nubz,

Great observation ..... this has been discussed a few times in the past and there is always a nice variety of opinions ..... Grin

I'm pretty sure that my system sounds great all of the time ..... but there are certain times that the sound is so real that I have a difficult time believing what I am hearing ..... a soundstage so palpable and the tone and timbre so convincing that I am totally caught up in the performance ..... 8)

Since I am using a PS Audio Power Plant to power my equipment, I don't think that power quality and fluctuations are a big issue for me ..... so it must be something else.

There are also times that I just cannot get "involved" in the music, no matter how hard I try ..... so I have to believe that at least part of it is "in my head" ..... Undecided

Thank goodness those times are few and far between ..... Grin

Regards,

Randy  
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #165 - 01/28/03 at 16:13:38
 
Randy,
I have Acrobat Reader 3.01. I even shut off my firewall and virus scan. No luck. All I get is a blank white page even after a ten minute wait. There is no address in the address bar.
Dave Undecided
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MikeS
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Re: Hell, those aren't big !
Reply #166 - 01/28/03 at 17:14:14
 
Dave (hurdy_gurdyman)

It looks as though Steve used Acrobat Distiller 5.0 to create it, so I believe you'll need Acrobat Reader 5.0 to view it.  

Peace,
MikeS
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nubz69
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Re: Hell, those aren't big !
Reply #167 - 01/28/03 at 18:53:12
 
I have the same experiences with music.  I don't own any true audiophile audio systems but there are times when I am listening to the right music at the right time and I am in the right spot between my speakers that the effect of the music on me is just erie.  I currently am using a pair of old mid-field monitors in the near-field for production and just plain listening and I have had a few times where I actualy get goosebumps because of the music and how it sounds to be all aound me.  Sometimes I wonder exactly what is more important(at least to me) when it comes to listening to music.  Is it the soundstage being realistic and not just plain flat?  Is it a truly flat frequency response from 20-20k?  Or is it something else.  I hope to one day have enough money to try owning my own tube amps and possible the RL-2's and mate them with a nice sub in hopes that I can at least get the whole range from 20-20k and have a good soundstage.  I have a feeling that is what my ears are looking for.
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Randy
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Re: Hell, those aren't big !
Reply #168 - 01/28/03 at 21:38:00
 
Dave and Mike,

Acrobat Reader 4.0 will open it ..... but, you might as well download the newest one while you're at it ..... Grin

Something else you might try is downloading the actual .pdf file to your hard drive and opening it from there.

Right click on the link that Steve provided and "Save target as ....."

Sometimes, .pdf files do not work very well across the internet ..... Tongue

Regards,

Randy
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« Last Edit: 01/28/03 at 21:42:28 by Randy in Caintuck »  
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hurdy_gurdyman
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Re: Hell, those aren't big !
Reply #169 - 01/28/03 at 23:55:09
 
Downloaded the newest Acrobat Reader and this time it worked. Guess I need to update my programs more often.
Dave Roll Eyes
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MagMan
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Re: Hell, those aren't big !
Reply #170 - 01/29/03 at 01:15:17
 
Steve,
Thanks very much. You made my day
Mike
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steve_f
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Re: Hell, those aren't big !
Reply #171 - 01/29/03 at 02:06:49
 
Hi Steve,
Thank you for sharing your "Zen Imperial" plans with us.
Take care,
Steve F
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Corpsdriver
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Re: Hell, those aren't big !
Reply #172 - 01/29/03 at 15:55:14
 
My copy of the plans are already at my buddy's shop, and he is figuring materials and costs for me. By the way, that means all the speakers on my web site EXCEPT the L-1590's are up for sale to finance this project... My HWK-15 doesn't go either.. Thank You Steve, i once again, bow to the east, towards the "Musical Mecca" in IL.

Jamie
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Brian
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Re: Hell, those aren't big !
Reply #173 - 01/31/03 at 04:03:27
 
Steve, can you tell us anything about optional brace "E"?  
Under what circumstances would I want to install them or not?
Is it 3/4" thickness like most of the other braces, or 1-1/2" like brace "D"?
And finally, do I put them against the side walls or out in the middle like brace "D" so as to form a kind of grill teeth in the horn mouth?  
Thank You
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bmar
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Re: Hell, those aren't big !
Reply #174 - 02/01/03 at 04:07:01
 
Steve, Thanks for sharing your redrawn imperial. You just have to love the horns and some of the things they can do. I've been working on some duel 10" cabinets lately. Maybe the rear load style of the imperial in a downsized manner might sound good too.

Mike,  We use the aluminum throats for a few reasons. I did not want the driver mounting directly to the wood of the horn. The begining section of the horn, or throat, can impart a lot of changes to the overall horn. This way the throat can be changed around and the mouth of the horn stays the same. you could have one horn with a few different throats and have all kinds of different sounds and be better suited for different drivers of choice.  So to answer your question, The aluminum throats are the means we use to couple two components and offer a variable too. Straight side throats had a lot more peaking issues along with more throat distortion.  The conical shape sounds, and measures better.

Bill
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homeyhomes
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Re: Hell, those aren't big !
Reply #175 - 02/02/03 at 21:40:57
 
ANYBODY in Los Angeles area
that is planning on building a pair of the IMPERIALS?

I would like to team up with someone if possible,
(Build two pairs at the same time).

I personally know 3 Cabinet makers that have nice
shops that will let Me use the shop & equipment.
one of the shops has two spray booths if You want
to Laquer the Cabs. Also cheap prices on the Lumber.
email Me if interested.

homey

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rgeorge
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Re: Hell, those aren't big !
Reply #176 - 02/02/03 at 22:34:50
 
Oh, Homey....
If only I had a place for them after they were built... Roll Eyes
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homeyhomes
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Re: Hell, those aren't big !
Reply #177 - 02/03/03 at 01:25:54
 
RGeorge,

I hear You, They're monsters.

I will be using them in My Shop (plenty of room)1300 sq ft.

and in about two years I will be moving them into
My new Listening room that I am going to build (plenty
of room Grin)   approx. 300sq ft.

It's not that I don't love My 4" horns, It's just with the
imperials, You can play any type of music at loud levels.
homey
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rgeorge
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Re: Hell, those aren't big !
Reply #178 - 02/03/03 at 01:30:42
 
[quote author=homeyhomes  link=1040842968&amp/165#177 date=1044235554]It's not that I don't love My 4" horns, It's just with the imperials, You can play any type of music at loud levels. [/quote]

...with only 1.8 watts!!  And, better yet, when you are playing, you are ALWAYS in the lowest reaches of the first watt - the death zone for most SS gear, but that is where the Zen really breathes.

Someday... Lips Sealed
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homeyhomes
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Re: Hell, those aren't big !
Reply #179 - 02/03/03 at 01:51:12
 
You said it. The first watt is pure gold, with these
super efficient badboys You will have major headroom
even with the little Zen.

I wish there was  a print on the high frequency
Horn lens.  But then it probably isn't that critical
as to the actual dimensions of the lens. just looking
at the photo of it can give a pretty good indication
as to the size.
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Brian
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Re: Hell, those aren't big !
Reply #180 - 02/03/03 at 03:29:56
 
Homeyhomes, there is information for laying out the tractrix curve for a treble horn at these sites.  
http://home.earthlink.net/~lotusblossom/_wsn/page2.html

http://www.melhuish.org/audio/horn.htm

http://www.geocities.com/tractrix12/

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« Last Edit: 02/03/03 at 03:38:53 by Brian »  
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homeyhomes
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Re: Hell, those aren't big !
Reply #181 - 02/04/03 at 08:17:37
 
20 - 30 hours of paper mache on those tractrix
horns sounds brutal.  I would think a wood one
like Steves would be less time consuming.
thanks for posting those.

homey
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Brian
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Re: Hell, those aren't big !
Reply #182 - 02/04/03 at 19:37:33
 
I think You're right.  I think the wood might be more musical too.  Of course I don't know which curve Steve is using but the ones at those sites ought to work well for a wood horn, either round or rectangular.
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DrN
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Re: Hell, those aren't big !
Reply #183 - 02/09/03 at 20:00:52
 
Check this out >http://home.att.net/~lkalin/index.html
Can you say HUGE?

Den
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Corpsdriver
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Re: Hell, those aren't big !
Reply #184 - 02/10/03 at 05:01:46
 
My Imperial project is in high gear (since recieving our tax return) I have a pair of JBL e140-b's and a pair of black widow 15's, (keeping with the mis-matched driver concept) and i have a bid in on some 2" JBL compression drivers on Ebay that i will fit up to these:

http://corpsdriver.home.attbi.com/id19.htm

I also ordered a new pair of Dayton series II subwoofers to go into my HWK-15. specs are:

Power handling: 300 watts RMS/425 watts max * Voice coil diameter: 2-1/2" * Voice coil inductance: 4.4 mH * Nominal impedance: 8 ohms * DC resistance: 6.3 ohms * Frequency response: 19-1,000 Hz * Magnet weight: 90 oz. * Fs: 19.0 Hz * SPL: 89.5 dB 1W/1m * Vas: 9.64 cu. ft. * Qms: 10.46 * Qes: .35 * Qts: .34 * Xmax: 8.0mm * Net weight: 19 lbs.

they oughtta do! lowest Fs i could find and the closest to a VAS of 10 cu.ft i could find also.
I figure, if they flutter in the HWK, i will load them into the Imperials... mix and match!

Jamie
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Zaltais
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Re: Hell, those aren't big !
Reply #185 - 02/24/03 at 13:30:51
 
Help me please
I cant download the horn plans, am I too late?
AHHHHHHHH
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Corpsdriver
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Re: Hell, those aren't big !
Reply #186 - 02/25/03 at 15:27:57
 
Gentlemen, I am sorry you guys missed out on the plans... Cry
so let me be the first to say:

PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPLLLLLLLLLLLLL! Tongue Grin

Jamie

I am sure Steve will have them up somwhere else soon.
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morpheous85
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Re: Hell, those aren't big !
Reply #187 - 03/02/03 at 20:45:27
 
I just found this topic last night. I listened to the file today! (I broke the rule that you shouldn't listen to it on your computer.) None the less, WOW!!! I believe you created a monster! How in the world are those two 15"s creating so much high freq? The recording sounded really good! Anyway, is it possible to get the plans?
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1electric1
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Re: Hell, those aren't big !
Reply #188 - 03/06/03 at 21:00:24
 
Why birch ply?

The first pair of folded horns I built were out of some 7ply stock with a mahogony veneer already applied. What the inner wood was I don't know. I got the stock on discount because the bottom edge had been stained from water damage, but was still 3/4". I know klipsch uses void free birch 3/4, but why birch or am I being dense and almost all plywood is birch?

I simply sanded mine, stained once and coated with polyurethane something or other. It was a hard surface and looked great.

If anyone has any pictures of how their imperials are coming along please share. I am buying my stock this weekend and wanted to ask about the birch.

Also, for the inner braces and such, can I not substitute soem other kind of stock? Is it the thermal expansion factor that dictates the use of the same stock on all pieces?

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Brian
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Re: Hell, those aren't big !
Reply #189 - 03/06/03 at 23:24:51
 
Birch is not used in common plywood.  Douglas Fir is used in most of the plywood made in America.

I would think there is more sonic difference between MDF and any plywood than there is between one kind of plywood and another.  I think most of the reason we only read about Birch for speaker building is because it finishes to a nicer appearance than Fir.
That last paragraph is specualtion of course.  
I don't know if Birch plywood is all Birch, or only the decorative surface ply with a less expensive core.  
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1electric1
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Re: Hell, those aren't big !
Reply #190 - 03/07/03 at 21:23:51
 
Alright I have to seek some advice.

I think building a top end for myself is going to be risky.

I would rather buy some top end horns and drivers, that I can sell and recoup my losses if they don't work out. Of course I would like them to work out the first time.

I want to avoid a seperate tweeter, and crossover issues I can handle myself.

I have my eye on some horn/compression driver auctions and would like to ask those of you in  the know a little about what I should look for.

I would LOVE to have a wood horn on top, but metal or plastic is fine with me, so long as performance is a great match for the bass horn.

Please tell me what you think.

btw, if anyone cares for my la scala plans send me a note. I have a couple versions.

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Brian
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Re: Hell, those aren't big !
Reply #191 - 03/07/03 at 23:52:26
 
Hi 1electric1, You may want to repost this question on the speaker builder's forum to get a wider audience.
Best of luck.  
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Edac
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Re: Hell, those aren't big !
Reply #192 - 03/20/03 at 07:09:06
 
I am a bit slow on the uptake here, but I thought I could offer an idea as to why Steve achieved 'stereo imaging' with his recording of the Imperial standalone...  It is simply the relationship between the two mics, the speaker and the room, a very cleaver illusion (not created by intent)!!

Basically, the only ways Steve could NOT have achieved a measure of stereo imaging in the recording, would to have been to have the mics directly on top of eachother, or to have had the speaker in a perfectly "dead" room positioned exactly between the two mics. (I can't comment on the lateral soundstage effects of the mismatched driver - I am sure that adds to the phenomenon I will describe, but is secondary to the effect only).

What you are hearing is two mics, removed from eachother, collecting information not only from the speaker, but from the effect it has on the room too.. To illustrate, the left mike might have been close to Steve's drum set, sucking up timy vibrations and resonances from it.  The right mic might have been next to a sponge chair -deadening the sound collection area for this mic.. Bingo!  there you have it! Two mics, doing what they orta, and picking up two different tracks of sound!  Stereo imaging follows.  This phenomenon can reproduce itself when recording a solo voice or instrument in the middle of two mics in a less-than-perfect recording environment - you might hear an "echo" for example off to the left and behind of the artist.. All that from a mono source?  Yes.  its easy really.  Hifi seems to me to be about  "mental gymnastics."   As Steve demonstrates, when you step out of the square, magical things reveal themselves to be logical, reasonable and ultimately understandable.   Wink
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Corpsdriver
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Re: Hell, those aren't big !
Reply #193 - 03/20/03 at 14:49:28
 
Face it... if your head was there, between the 2 mics, you would have heard the same thing... the speaker, and the room. isnt that how everything works?

Jamie
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Edac
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Re: Hell, those aren't big !
Reply #194 - 03/20/03 at 19:32:54
 
Jamie, I agree - to a degree!  The mics obviousley are further apart than your ears are, lets say 2m apart, therefore increasing the amount of differing information recieved.  Reduce the distance between the mics and decrease the variation in soundtracs recieved, until the point where the mics are on top of eachother and receiving identical info. Our ears are too close together (!) probably to detect the phenomenon described..

Another point to consider here is the angles of the mics in reference to the front of the speaker.. Steve said it was far from ideal with the mics being at right-angles..  This alone brings in miniscule, yet significant time delays, if one mic was behind the the other...  

I strongly suggest that if Steve were to replicate his recording, with the mics together and dirctly in front of the speaker (at a similar distance as in the first recording), your playback of the resulting recording would sound a great deal more 'mono'.

Try it if you have a sereo recording setup....  I might turn out to be full of you know what.. I hope not!
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Steve Deckert
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Re: Hell, those aren't big !
Reply #195 - 03/22/03 at 01:00:23
 
You are both right.  :o

The sound during the recording that night did not sound like mono then either unless you stood directly in front of the speaker at close range.  A large part of the stereo effect was due to the SPL we were playing the speaker at.  I would say around 100 dB ave.  At that level different tones locate on different surfaces which triangulate around the room in different locations.  At a lower playback level I suspect the effect would be reduced.

You would have heard a stereo image if you stood between the mikes that night, however it stands to reason it should also have been enhanced on the recording from the larger distance between the mikes.

Also, each mike was located on the bottom corner of the grill of a 15 inch loudspeaker with rotted foam surrounds.  I believe this enhances the sound by adding additional delay.

Steve
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Corpsdriver
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Re: Hell, those aren't big !
Reply #196 - 03/24/03 at 19:58:06
 
I bet you own a Bose system edac... i built my first "surround" system out of 6 old stereo speakers and a tube clock radio when i was 10 nyears old. I was a Professional Audio engineer at the ripe old age of 13. you will really need to come up with something better than that, to make me not "Hear the room" unless my head is in the horn.
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Edac
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Re: Hell, those aren't big !
Reply #197 - 03/25/03 at 00:08:29
 
Hey Corpsdriver..

I don't profess to know all there is to know at all, I am only relaying a theory.. I have spent six years selling and setting up hifi - not long perhaps, but long enough to have experienced a few things..  As to your reply, well, it is slighty ambiguous.. Perhaps you should have set aside your copy of "Valve Manual: 1936" when you were ten, and picked up "English Language For Beginners".  I can recommend the section titled "How To Communicate Effectively With Anything Having An IQ Above That  Of A Hedgehog"..

No Bose system in sight here, sunshine.  Just tubes, and efficient speakers..  Thats why I'm here at Uncle Steves'.

Pull your head out of the horn.  Love Edac.
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Corpsdriver
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Re: Hell, those aren't big !
Reply #198 - 03/25/03 at 15:47:21
 
My apologies, for coming off like Gomer Pyle after a colonoscopy, I had quite an attitude yesterday. (oh, and double the apology for the Bose incinuation!) The point I WANTED to make was, of all the theory in the world, only about 1% stands up to practical application. (ie. Bose... All show, no go.) My claim to fame (as it were) came from using rooms during recordings, not by close micing in a dead studio and adding it all back in electronically.

Love backatcha,
Jamie

P.S. that was Valve Manual: 1972
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Edac
Ex Member



Re: Hell, those aren't big !
Reply #199 - 03/25/03 at 18:22:07
 
Jamie, we all have our off-days!  

I agree wholeheartedly with your sentiment about "theory".  I have set up enough subwoofers to know that theory/reality are seldom the same!  You should see where some of them ended up!

Congratulations on the friendly reply to what was an intentional stir.  Considering there was no such thing as Valve Manual: 1990 when I was ten, I have to bow to the superior knowledge I find on sites like this.  Everything added to these pages is valuable in one sense or another.  

I'll NEVER forgive you for the Bose thing!!  Although I am off to Police college, those little bunk rooms requiring nothing more than a little cube + sub of some type..  Needless to say - DIY will be the key.  Maybe some Imperials on a 1/15 scale!!

Cheers, Cade.
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MikeS
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Re: Hell, those aren't big !/ wood horn lenses?
Reply #200 - 04/17/03 at 16:31:24
 
Steve,

Did you ever make any drawings/plans of the wood horn lenses?  I did very much appreciate the Imp. plans you made available!

Thanks,
MikeS
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sparkplug
Ex Member



Re: Hell, those aren't big !
Reply #201 - 11/07/03 at 23:34:57
 
I can't believe I'm posting on somthing said almost a year ago.  I'm about half way through this thread, and I couldn't resist.

<As I applied the varnish, while it was still shiny and laying on top of the surface, the sound would come out of the varnish!  Just a 6 inch square area in the throat raised the presence by 3dB. It was unmistakable, yet I couldn't believe it.>

Could this be caused by the air density change caused by the varnish vapors??

Jake
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richard03
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Re: Hell, those aren't big !
Reply #202 - 11/08/03 at 18:00:51
 
has anyone got any predictions for how a pair of imperials would perform outdoors , any feedback would be much appreciated....thanks
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Brian
Ex Member



Re: Hell, those aren't big !
Reply #203 - 11/09/03 at 16:41:44
 
Hello richard03,  
Indoors a speaker usually has some bass cancelation nodes caused by wall reflections.  These cause the bass to have dips at various frequencies.  Because of the lack of this rippled bass, I believe any speaker would be more perfect out of doors than in.  
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Brian
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Re: Hell, those aren't big !
Reply #204 - 11/09/03 at 16:45:24
 
Sparkplug, Your air density idea seems plausible to me.  
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weasel2htm
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Re: Hell, those aren't big !
Reply #205 - 11/11/03 at 03:04:25
 
I've Played both the wac and the mp3 on a variety of systems (but no HT systems yet)  WOW  Home system Sansui 5000X and Paradigm Phantoms  Sounded cool, wow Played in my car, worn out Coaxials Stock Tape player and DB12 The car is where I got an Idea on the depth of the room and was in general shocked (the DJ talking is what sounds cool) Played the recording through the youth room sound system at my church (EV PSX2000 Powered Mixer 500 watts/ch and 4 Sound Tech speakers with 12" woofers and horn tweets) I had told a friend of mine about this thing and I gave him the website but he could not believe the treble from the 15s of this speaker the room is too echoey for much stereo effect.  OK now that I got my rambling out of the way I will sya one thing about this speaker  WOW  I have no room for something of this size so I guess the phantoms will have to continue doing their job.
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strobe
Ex Member



Re: Hell, those aren't big !
Reply #206 - 12/16/03 at 21:25:00
 

[quote author=Brian  link=1040842968&amp/195#205 date=1068396324]
Sparkplug, Your air density idea seems plausible to me.  

[/quote]

RE: <As I applied the varnish, while it was still shiny and laying on top of the surface, the sound would come out of the varnish!  Just a 6 inch square area in the throat raised the presence by 3dB. It was unmistakable, yet I couldn't believe it.>

I'm not so sure about vapors and am more inclined to the theory of some sort of surface tension dynamic.  Wonder if some fuzzy material (like a velour) coating the throat area would have a similar effect by affecting the compression wave transmission into the horn material?  Thoughts?
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Braggi
Ex Member



Re: Hell, those aren't big !
Reply #207 - 12/19/03 at 17:44:46
 

[quote author=strobe  link=1040842968&amp/195#207 date=1071609900]


RE: <As I applied the varnish, while it was still shiny and laying on top of the surface, the sound would come out of the varnish!  Just a 6 inch square area in the throat raised the presence by 3dB. It was unmistakable, yet I couldn't believe it.>

I'm not so sure about vapors and am more inclined to the theory of some sort of surface tension dynamic.  Wonder if some fuzzy material (like a velour) coating the throat area would have a similar effect by affecting the compression wave transmission into the horn material?  Thoughts?
[/quote]

I've heard over and over how important a smooth surface is to the function of horns. What could be smoother than the surface of a fluid? I imagine that sound waves are affected by friction. Reduce the surface finish (that is, make the surface smoother) and the sound will flow better, especially at high pressures like in the narrow throat of a horn.

Mystery solved?
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morpheous85
Ex Member



Re: Hell, those aren't big !
Reply #208 - 03/22/04 at 04:25:30
 
You have my vote.

Jason
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Braggi
Ex Member



Re: Hell, those aren't big !
Reply #209 - 10/21/04 at 04:30:52
 
OK, time to return this thread to the top of the heap, may it live forever!

Well, I never read whether Steve D. liked his Selenium 2" drivers or not on the big HF horns so I'll assume they're nothing to crow about. I have a pair (three actually) of Emilar EA-175 drivers They're only 1" exit but they sound very good. I have a lot of other mid/high compression drivers to try too and several different metal horns. Will someday build some wooden horns though not sure which design or manufacturng process I'll use.

For now I'm putting siding on my new woodworking shop. In a few weeks I'll most likely get started on my first pair of Imperials. I'll try out my 30 year old Altec 421-8LFs in them. I have four. I imagine I'll like 'em. If and when money allows I'll probably buy Altec 515s for the second pair.   Smiley
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bigmike216
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Re: Hell, those aren't big !
Reply #210 - 10/21/04 at 05:47:08
 
Sounds like lots of fun Braggi! I wish I had a space dedicated to woodwork, that didnt involve pulling out the cars. Smiley
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gexter
Ex Member



Re: Hell, those aren't big !
Reply #211 - 08/12/05 at 06:26:33
 
I thought that was a good idea to bump up the good threads
so here is the one of the best.
an oldie but a goodie and things have not changed as of yet.
But the Ip SO is on its way.
cheers
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J_Rock
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Re: Hell, those aren't big !
Reply #212 - 02/23/06 at 21:26:00
 
Bump
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jj420
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Re: Hell, those aren't big !
Reply #213 - 07/24/06 at 19:19:26
 
'nutha bump, just keepin' the faith.
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spock534
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Re: Hell, those aren't big !
Reply #214 - 08/04/06 at 04:15:42
 
I just spent 2 hours reading this thread.... best waste of my time ever!!!
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Terry
Ex Member



Re: Hell, those aren't big !
Reply #215 - 02/06/07 at 07:49:21
 
Great I found this thread!!

Thanks Braggi!

TG Smiley
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gexter
Ex Member



Re: Hell, those aren't big !
Reply #216 - 02/07/07 at 01:54:23
 
Whoooo Hoooo
my fav thread for ages the WO32 one got deleted but this one remains.
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Terry
Ex Member



Re: Hell, those aren't big !
Reply #217 - 02/07/07 at 09:21:31
 


I brought it back to the top for selfish reasons.   And because I didn't want it to fall of the edge of the world, threads have a way of doing that.  This one started this whole forum.

TG Smiley
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buzz
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Posts: 393
Re: Hell, those aren't big !
Reply #218 - 04/06/07 at 19:59:35
 
Bump - The all time favorite Decware thread!
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Gexter
Ex Member



Re: Hell, those aren't big !
Reply #219 - 04/07/07 at 03:50:02
 
yep!  :)
read it again for the first time   Wink
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Renato
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Posts: 2
Re: Hell, those aren't big !
Reply #220 - 05/09/07 at 15:59:06
 
A sound system designer named Richard Long stated in one of his papers he designed a cabinet called the Waldorf. It is similar to the JBL Double 15" scoop enclosure but is based on the Jensen Imperial design. The enclosure was designed with a hyperbolic rather than a exponential flare. Is the decware imperial design also a hyperbolic flare ?. Also if you would, please explain the difference between the two flares ?
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buzz
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Posts: 393
Re: Hell, those aren't big !
Reply #221 - 05/09/07 at 21:55:22
 
Renato wrote on 05/09/07 at 15:59:06:
A sound system designer named Richard Long stated in one of his papers he designed a cabinet called the Waldorf. It is similar to the JBL Double 15" scoop enclosure but is based on the Jensen Imperial design. The enclosure was designed with a hyperbolic rather than a exponential flare. Is the decware imperial design also a hyperbolic flare ?. Also if you would, please explain the difference between the two flares ?



No comment on flares, just a few tidbits about Richard Long. He was the audio engineer for Studio54 and other famous club scenes. Having died years ago, Gary Stewart has taken over where Richard left off. Arguably the best club sound in the world. http://www.gsany.com/
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Steve Deckert
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If the 1st watt
sucks why continue?

Posts: 2392
Re: Hell, those aren't big !
Reply #222 - 05/10/07 at 04:55:17
 
Shortly after this thread started, the original wav file was removed.  It is 75 megs and that equals about a months worth of posts on this forum.   Anyway, without this original file (uncut) the thread just isn't the same.  So here it is:

http://virtualvault.freedom2surf.net/205752

Steve Smiley
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Brian
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Posts: 288
Re: Hell, those aren't big !
Reply #223 - 07/22/10 at 10:29:43
 
Concerning the preference for mismatched speakers in the Imperial, I found this exchange on the Weber Guitar Speakers Q&A page:
http://www.webervst.com/sptalk.html

From: Gerald C. Lopez
I have two 8 Ohm speakers that I can wire either parallel or series to my tube amp for an impedance of either 4 or 16 Ohm. My amp has both 4 and 16 Ohm output taps. Are there any sonic differences or benefits of series over parallel wiring or vice versa?

Gerald, connecting two speakers in parallel is an old trick to smooth out speaker response and enhance the damping of either speaker. HIFI designers took it one step further by connecting two speakers of different sizes in parallel. A speaker has a large impedance increase at its fundamental resonance, and depending on the installation, this can cause the speaker to sound boomy or out of control. By connecting two speakers in parallel, particularly two speakers of different sizes with different resonant frequencies, each speaker will tend to quench or dampen the boominess of the other. Since no two speakers are exactly alike, even with two of the same size, that damping will occur, however slight, for any speakers connected in parallel.
    For speakers connected in series, there appears to be less control, and more of what is called 'back EMF' from the speakers fed back into the output circuit. While that seems rather chaotic, many players prefer the series connection, as it gives them a more textured tone, enhanced breakup, and overall a more desireable tone for guitar work. It's totally subjective, of course, and many factors affect the end result, such as voice coil size, gap energy, closed back/open back cabinet, output circuit damping, etc.

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Brian
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Posts: 288
Re: Hell, those aren't big !
Reply #224 - 07/24/10 at 18:13:54
 
On the subject of the high frequency horn being difficult to make; Western Electric once made a horn (model KS6368) of cloth stiffened with plaster the way a plaster cast bone splint is made.  Perhaps shaping the pattern the cloth is to be formed on would be equally as difficult as making the wooden horn, but to me it does not seem so.  
At any rate, I thought it something to consider for anyone thinking of making a treble horn.
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Brian
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Posts: 288
Re: Hell, those aren't big !
Reply #225 - 07/27/10 at 04:03:53
 
Four 12s?
I would like to try four 12 inch speakers, two Bass & two mids arranged cruciform. With the cabinet being around 38 inches wide, the two Bass speakers could be pulled out to the sides making room for the two mids to stack up in the center.  Four 12s have area midway between two 15s & two 18s. But with lighter moving mass in each speaker, presumably the motor can exert better control of the cone for a faster, cleaner sound.  
With the big surface area, I guess the Imperial would still have the "hit", the crack! that comes from the twin 15s.  

I was thinking of using Weber guitar amp speakers which are available with 32 Ohm impedance.  The four of them could all be paralleled for 8 Ohms.  
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« Last Edit: 07/30/10 at 01:39:51 by Brian »  
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Valiant
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Re: Hell, those aren't big !
Reply #226 - 07/28/10 at 02:04:46
 
I got good results using 4 x 8" on my half Imperial. Imagine 8 x 8" (or even 10 x 8") on a Full Imperial. Still needed a tweeter for the high range though.
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Brian
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Posts: 288
Re: Hell, those aren't big !
Reply #227 - 07/28/10 at 03:17:02
 
For a tweeter with four 12s, I figured use the same wood horn as with the two 15s.  Although a lateral array of 2 or 3 bullet tweeters would be less work.  The center one would point straight forward, while the outer pair would be splayed outward a few degrees for dispersion since bullet tweeters do not otherwise have much dispersion.

These bullets could mount between the two midrange woofers if these were pulled to the top & bottom edges of the baffle.

Perhaps this tweeter array ought to be on a board which can be rotated up or down so that if they are too intense they can be pointed partially toward the ceiling or floor to get them out of the face of the listener.
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Brian
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Re: Hell, those aren't big !
Reply #228 - 07/30/10 at 01:40:38
 
A single 18 inch Bass and two 12 mids would have the combined area of two 15s.
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