Planning my first horn project

[eRiCdWoNg]

....Id like to go to the efficient side of the ball game and try something new. I have larger Magnepans right now and that = power gobs, low efficiency, lots of room needed. I've always been intrigued by klipschorns and horns in general, especially bass horns. Although I never got around to building a Labsub. My experiences with horns right now is limited to Electro-Voice Constant Directivity horns on the speakers of my PA system. So, I know a little about horns but I'm not completely in the dark. I also had a Cerwin-Vega LR36 PA sub..

Soooo.... this is my plan. I also want to build a full horn system including the subs. I'm willing to make it ridiculously large (but not so large it takes up the basement) so that it will include a hornloaded bass section. This will be strictly home use. Probably a 2 or 3 way design. I'd like it to sound good (duh) but also be the "simpler" of a design, sorta like how most everybody's first DIY sub is a sealed box- usually a car sub in a prefab'd enclosure.....

I should be able to corner load the bass sections, or at the very least, rear wall and floor load them.

I'd also like to use these with a tube amplifier setup (never had these either). Probably 1 or 2 Dynaco ST70s I can tinker with.

Questions (i've searched here and the net but still these remain):
The bass horn concerns me with the delay especially if it is going to be very large. I know the labhorn caues of the delay you must delay the "mids and highs" to compensate.

Where can I get HornResp WITHOUT it full of spyware/viruses?

There used to be a good bass horn FAQ I bookmarked but the link is now dead

What "parameters"/characteristics makes a driver more suited for horn loading then another?

Any recommendations on drivers based my above information? I'm thinking compression driver definately for the "top", but not so sure abuot what to put for the mid driver.

I wonder if this is crossing too many bridges at once or what.

[mikee12345]

If the delay is concerning use a larger woofer for the bass so the horn length is shorter

www.melhuish.org has horn infos.

Where can I get HornResp WITHOUT it full of spyware/viruses?

since when does it have spyware/viruses? how do you know it has them!!!!!!!!!!!!!!!!

What "parameters"/characteristics makes a driver more suited for horn loading then another?

get the ML UTIL program!!!!

Drivers with specs such as the LAB12 work optimally on low bandwidth basshorns.
eg low Fs=20 mid Qts=0.4 Vas=130L
Note that drivers with high BL and low Qts like the peerless XLS enjoy long horn with higher compression ratio(to my modeling ability)
A driver with low distortion already and shorting ring would be a plus.

Go 4way unless you enjoy 50hz-400hz straight midbass horns!!!

Comp driver
Midrange
Some sorta midbass 70-300hz (15" DR )
highly folded hornsub

or you could go compdriver,12"/15" unit + sub
but i dont trust the large bass units beaming near 1khz!

Note that my 40hz horn,with $19 8" cheapie sub sounds as good as,or better than my EBS jbl2226 ported box in the midbass.

[nowater]

IMHO you will not get great results with a 2-way all-horn speaker. Only a master like Bruce Edgar can do it, and he uses incredibly expensive drivers to get away with it.

Best 3-way diy approach for a first horn is probably to emulate Bruce Edgar's 3-way approach which was built around a straight rectangular tractrix midrange horn with a 300Hz mouth, operating from about 400Hz to 5kHz. He used any of several reasonably efficient cone midrange drivers for good results initially, then found the Dynaudio D54AF (I think) efficient dome gave great results. A decent high efficiency pro audio tweeter was added, there was a Polydax/Audax PR120i for cheap, or a JBL slot tweeter or its Beyma clone. For a simple time aligned bass horn he used a straight, rectangular, short 50Hz 1/8 tractrix with a 15" pro audio driver and a 1:1 throat to keep it short. In all honesty the bass was dying below 80Hz at best, he should not have used tractrix, but hypex is longer and optimally needs some throat compression which makes it longer still. So the Edgar 3-way is very tidy, short, time-aligned and affordable (for a horn), but really needs a subwoofer. Edgar later designed a huge horn subwoofer for this purpose which others nicknamed The Refrigerator, and it goes against the back wall between the 3-ways. So an upgrade path for you could be to do the 3-ways at first, then try adding a standard sub and see if you like it, and if not later upgrade with a diy version of The Refridgerator.

Hope this helps? Grant

[jdunham]

Have you had a good look at Bert Doppenberg's site? There are plenty of full range horns (shown in the showroom) using his front horn's coupled with various horns for the bass.

Those people using the LaScala bass section, seem to have found a good way of getting a "nearly full-range" horn, that covers the 50hz to 20hkz range. You could then add a monster single horn sub as suggested above, or try a pair of monopole subs.

Regards,

Jonathan

[nowater]

Thanks Jonathan for reminding me of the Bert-type speaker; I had forgotten about these Lowther-type, full-range-driver-with-front-waveguide-or-rear-horn "horn" speakers, when I said you won't get great results 2-way. I am somewhat suspicious of this type, but lack experience, and they have their advocates.

Grant

[GM]

>Questions (i've searched here and the net but still these remain):
The bass horn concerns me with the delay especially if it is going to be very large. I know the labhorn caues of the delay you must delay the "mids and highs" to compensate.

====

Correct, though just to be clear, the lows are delayed WRT the mids and the highs are delayed WRT the mids.

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>Where can I get HornResp WITHOUT it full of spyware/viruses?

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Since when did DB's site become infected? I recently finally got around to downloading the lastest rev and it was clean.

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>There used to be a good bass horn FAQ I bookmarked but the link is now dead

====

Learn something new every day, I didn't know there was one, but I bet it was full of rules-of-thumbs, so probably more misleading than educational.

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>What "parameters"/characteristics makes a driver more suited for horn loading then another?

>Any recommendations on drivers based my above information? I'm thinking compression driver definately for the "top", but not so sure abuot what to put for the mid driver.

====

This gets a bit too involved to cover all the variables for the different BWs, so without knowing the desired BW/efficiency, about all I can say is that the higher the gain and/or BW desired, the more the driver must be pistonic over the horn's passband.

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>I wonder if this is crossing too many bridges at once or what.

====

Depends on which system format you choose. For a first effort, a point source driven front loaded LF/midbass and 'fullrange' or compression horn isn't very hard, then add a sub if required. To keep the LF/midbass horn a reasonable length, use multiple drivers.

Once BW/efficiency is known, then folks can offer driver, lens, and XO suggestions.

GM