My new homemade full range horns

Rob

Super Member
My new homemade full range front horns

I finally got myself in gear 2-1/2 months ago when the Selenium 12C01P, 12" coaxial drivers I'd been looking seriously at for two years finally came on sale at www.partsexpress.com and finally built a set of full-range (down to 50Hz) exponential bi-radial horns (entirely my own design) for my home theater/stereo listening suite. These are now finished and the room acoustical treatment also almost completed. I've been listening to them on an ultralinear P-P 6CA7 (Mullards) stereo amp I built 27 years ago that is conservatively powered for only 20W/ch. This package sounds fabulous!!! I will link to a full report in the future but here is a shot of one of the horns under construction to give you an idea what I have been up to. The completed cabinet on casters is 76 in. tall, 27-1/2" wide at the mouth and 5 ft. 2 in. deep. The rear chamber is 3.6 cu.ft. and tapered like the closed end of a TQWT but not so drastically. It is damped with fiberglass wool. The flared horn petals are molded in fiberglass, strengthened with imbedded steel hardware cloth mesh and deadened with imbedded lead shot. The cabinets are made from 3/4" MDF with angle iron along the long front sides to add strength and tapped 1/4-20 to accept the steel crossbraces which were anticipated to possibly hold vertical lens plates, not really needed. The rear chamber and driver unbolts in order to get these 300 lb. beasts down the stairs.

They sit at each side of a 6x8 foot front projection screen in a 40 foot deep room and are listened to at a distance of 16 feet. They work incredibly well as close as 9 feet.

I have a set of four Altec A-7's set atop four 816-A short horn flare bass bins (like a short A-7) and I know from experience that those A-7's DO NOT WORK in a typical living room. You need to get 35 feet out in front of them before they phase correctly. My new horns do not have this characteristic at all. :)

These horns are very efficient and I now wish to try my hand at a ~30 watt/ch SET amp (probably 805's) and also an OTL design with a farm of 6080's for some critical comparisons now that I have the speakers and anechoic listening suite to hear the differences.

Toobz through horns clearly rule, ...and rule clearly!

Rob
 
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Here's another picture of my new horn design.

Rob

P.S. For finished picures of these see my post in the Home Theater Forum called "No room for surround". ;)
 
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So is this you in your senior years? :rolleyes: :D

ikedasm.jpg


Just joking. Your obviously hard core on horns. I'm not that knowledgable, but I do know I like Altec's with horns.
 
Wow Rob...Big time stuff there eh? I am with you though. I think horns done right with proper amps are likely the ultimate in sound. I keep thinking some day it will be something that I dabble in. But I need to keep the scale smaller. I have some 95db speakers that I eventually hope to get a pair of SET mono blocks to drive them. Sure would like to hear your system. :cool:
 
I should add that while watching the power level into my horns I have concluded that a 2 watt/ch SET amp would be entirely adequate for listening to stuff like classical guitar and piano or zylophone stuff. I mean Donna Summer's "I Feel Love" from my vintage vinyl collection was really rocking the house at just 10 watts!

When I make noises like I want 30 watts/ch when discussing building some tube amplifiers, it is probably because of what I have been used to in the past, house pounding capability.

I tried my 125 Watt/channel Sansui 9090 receiver on these horns last week and was wearing those earphone syle hearing protectors. The SPL's were up there but still clear. The Selenium drivers are conservatively rated at 250 Watts RMS continuous pink noise. I'm not worried about hurting them.

Horns on toobz clearly rule, ...and rule clearly.

Rob
 
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Originally posted by Wardsweb
So is this you in your senior years? :rolleyes: :D

ikedasm.jpg


Just joking. Your obviously hard core on horns. I'm not that knowledgable, but I do know I like Altec's with horns.

I had run across that Japanese photo on my web serches for horn info. This guy is a collector. I suspect he has a bunch of Western Electric equipment but personally don't recognize much of whats there. Not trying to make any fun of the gentleman at all but I think the photo would have been more 'theme comprehensive' if he had been sitting there with a prop hearing horn pressed to his ear. :) Yeah, that'll be me in a few years...a hearing horn, a full range horn on wheels as a sidecar to my electric wheelchair!

Rob
 
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No horns, except in the old Mach Two's downstairs, but that picture, minus the beard, could be me now! A wall of speakers, wire all over the floor, and stacks of gear (& bookcases) all 'round.
Mine's a fresh ground cuppa joe, though.

Pete, see guys why Dr. Klipsch FOLDED the bass horn?

:dunno: :D :D
 
very cool! You look like the mad scientist working on frankenstien in the first picture. Intensity!
 
Nice Rob...real nice!


Any suggestions on amps for me? Ya...ya...I understand it's all subjective and that...but after I get the speakers done I'll have to start lookin' into amplification.

The speakers will be 500Hz EdgarHorns(salad bowls) with some JBL 2441 compression drivers...on top a Fane 5022 tweeter(this will be driven by one amp) Then on the bottom a TAD 1601 woofer in a sealed enclosure.

I listen to all sorts of music...some demanding and some not so. I have heard similar speakers driven by a 45 SET amp...and while most of the time it would be fine...I still find that once in a while the dynamics that the horns can produce want just a little more. I'm thinking of possibly PP45...tho I'm not set or sure either. Amplification is a ways off...so I'm just looking into stuff right now. Oh, any comments suggestion for the bottom appreciated to.

Thanks....take care>>>>>>>>>>>>>>
 
Gonefishin,

I'm no expert on 45 amps, in fact except for a vintage cathedral radio I had when I was a kid, I've never listened to one since. I think bi-amping is the way for you to go, especially since you aren't running a horn bottom, and I also agree with you that something with a little more horsepressure might be useful at times for the top end. The SE 300B variants are suppossed to be sweet. I haven't heard any of those yet either, but am about to make a stereo pair of higher power SE triodes amps using the fairly large 805 transmitting triode. That tube will easily make 30 watts+ inclass-A and will have enough jam to run my full range horns down low where power is still needed, despite above average speaker efficiency. So it takes 30 watts instead of 600 watts to shake my house. I went away from bi-amping my main speakers when I just recently went to these horns for simplicity and because I wanted to evaluate low power tube amp designs.

If you are bia-amping I don't think there is a need for tube amps in the bottom end. I think good SS amps are entirely adequate to power woofers.

Rob
 
Thanks for your reply. Right now, I already have a SE300B amp...and I will give it a try on the tops. Actually, I will probably use it on the woofer for a while too...until I can build/buy something with a little more power. I also agree with you that I may not need a tube amp on the bottom...but, my concern is the meshing of the woofer with the midrange horn. The woofer will be crossed at 800Hz...I guess I got a little experimenting to do ta see how things sound.

I have heard a couple homemade amps using the 805...and if they may give me a glimpse into what yours may sound like(which it may...or may not) It should certainly have plenty of power and punch...with a soundstage that should be out of this world. Keep us/me updated on your thoughts and progress.


Take care>>>>>>
 
Originally posted by gonefishin

... I have heard a couple homemade amps using the 805...and if they may give me a glimpse into what yours may sound like(which it may...or may not) It should certainly have plenty of power and punch...with a soundstage that should be out of this world. Keep us/me updated on your thoughts and progress.


Take care>>>>>>

gonefishin,

Boy, now you have me even more motivated to build this package with the 805's. Do you know what o/p xfmers the ones you heard were using and the plate load Z and wattage rating? I don't suppose you saw what tubes were used for drivers? That is still to be decided.

Thanx,
Rob
 
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