Horn speaker system on the horizon.

[tade]

I have a pair of altec lansing 288c compression drivers and one 12" dayton hifi sub.

I want to build some edgar tractrix horns for the drivers and run the sub up to 500hz.

Will this sub do this well? To get 500hx down I will need a fairly large box, what are some tips to keeping a such a large widerange box from sounding "boxy"

Should i try and push the size down to elevate the standing waves inside the box then use a linkwitz transform?

Give me some feedback!
Many thanks

[sreten]

Hi,

mono up to 500Hz won't sound too clever under nearly all circumstances.

I can't see the sub driver getting to 500Hz anyway.

/sreten.

[tade]

: ) yeah, sorry bout that.
what i meant to say is that ultimately i want two of those sub drivers one per side. I really like the command that these woofers have and they are rated to like fifteenhundred hertz.
I would really like to avoid another driver and another crossover. ie a horn, a mid, and a subwoofer. I believe at some point i will add on a passive supertweeter from 16,000hz.

Thanks for reading

[tade]

bumpo

[mike.e]

The physical volume of the sub is determined mainly by the low frequency cutoff chosen. What do you desire?

F3 = 50hz
F3 = 25hz?

A small, 36mm thick MDF walled enclosure is probably the best you can do without getting fancy.

[sreten]

Originally posted by tade

Will this sub do this well? To get 500hx down I will need a fairly large box, what are some tips to keeping a such a large widerange box from sounding "boxy"
Many thanks

Depends on the driver completely which dayton 12" sub ?
An unboxy box ? lots of bracing basically.

Originally posted by tade

Should i try and push the size down to elevate the standing waves inside the box then use a linkwitz transform?
Many thanks

Stuffing the box will totally eliminate standing waves.

/sreten.

[tade]

cool.
Ok, so here is what i am thinking. I want the box to be tall enough to rest the horn on at ear level or maybe just below, incase I add a tweeter. Maybe I can angle the whole thing or perhaps use an angled rear baffle to direct the sound waves down into two or three cubic feet of light stuffing. Heavily brace that mess and i should be off to a good start.

By the way it is a dayton 12" hifi.

First thing is first, Ill go buy wood for the horn. I have no access to a lathe, so i plan on cutting rings and stacking them, then finishing with lots of rasping. then i suppose some sort of inner coating like construction adhesive or something that will get hard and is cheap, like me! Is a smooth inner surface critical, and has anyone heard a short tractrix horn? I really would like to have my sound be on the laid back side than the bright side.

Many thanks

[joe carrow]

I saw the results of some tests that said that sub is quite solid up to at least 300 hz. Beyond that it runs into the usual trouble with cone breakup and energy storage that aluminum cones are prone to.

I think you should consider a different driver to bridge the gap between the 12"s and the horn. You'll probably not get efficiencies very close, so that sounds like an active crossover is in order- at least between the subs and the rest.

Two of these sub drivers per side could do quite well in an open baffle dipole. They're supposed to be very quiet in operation without much turbulence, and 14mm isn't too bad for xmax.

That gives you controlled directivity with the horn, transitioning to (what?), then to dipole bass- this could be a good system with minimal room interaction.

[tade]

Hmm, dipole bass i think is out of the question at least using these drivers due to cost right now. Perhaps i can go dipole with another driver from 500 to 100 then use the twelve to fill in below that in a small box with a transform.

i am already going active with a LR 24db/octave

do you think that playing around with damping compound may extrend the range of this driver? i would sacrifice efficiency for simplicity.

thanks

[sreten]

http://www.stereophile.com/loudspeak...287/index.html

for some inspiration.

Hi,

I severely doubt the dayton driver will work well c/o at 500Hz.

With the horn whopping sensitivity it makes sense to use a sub amp
to drive the sub and a low power Class A amplifier - presumably valve
to drive the horn.

I'd say you need a high sensitivity 12" to run from Fbox to 500Hz.

I'd use a passive crossover to the horn and drive both with the low power amplifier.

I'd arrange for the mid 12" box alignment to be Linkwitz Riley.

Then your sub amp also needs LR rolloff to be compatible.

The Dayton sub Qts is too low IMO for open baffle, use sealed loading.

If you want lots of low bass get a sub amp with adjustable bass boost.

Making all those wooden rings and the filing sounds a pain.

I'd also suggest making a turntable, using it for a plaster cast of the horn.

Coat this with wax and build your horns with GRP (glass reinforced plastic)

/sreten.