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Hell, those aren't big ! (Read 139403 times)
Brian
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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
Ex Member



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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