[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

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

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.

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

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?

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

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

[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 .....

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" .....

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

Regards,

Randy  

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

Dave and Mike,

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

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 .....

Regards,

Randy

Steve,
Thanks very much. You made my day
Mike

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

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

Oh, Homey....
If only I had a place for them after they were built...

[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...

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/

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.

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

Gentlemen, I am sorry you guys missed out on the plans...
so let me be the first to say:

PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPLLLLLLLLLLLLL!

Jamie

I am sure Steve will have them up somwhere else soon.

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?

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.

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.  

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!

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.

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