Tractrix Speaker Project: Advice Wanted

[Cornwalled]

Hello all,

For a long time, the thought has been in my head to create a speaker based on the tractrix midrange horn. This is spurred by my dissatisfaction of the resonances and coloration inherent in my Cornwall's exponential horns.

I'm not really interested in utilizing the existing Cornwall in any capacity. I would rather use a horn loaded bass as well, rather than the Corn's ported cab, which is boomy in my room. However, I'm not totally sure what the best approach would be to do this. Also, my budget is limited to around $1,500 total, which I know isn't much. Here are my proposed thoughts. I would be interested to see what you guys think.

For the low frequencies, I have a few ideas. All entail using used speakers. One is to use a La Scala bottom. Another would be the Peavey FH-1 with the K-33-E's from my Cornwalls (FH-1s can often be found cheap, and seem to be pretty well thought of on here). The third option would be a set of EV Sentry IV bottoms. These cabs are available to me for $260 each loaded, and use dual 12's in a horn loaded enclosure, supposedly strong to 50 Hz. Anyone have any experience with these? If I used the EV's, I figured I would lay them down on their sides, as that would seem to put the midrange horn at about the right height, then somehow put the tweeter on top of the MF horn. Unless someone knows of a way to do a good 2 way?

The midrange is where things get tricky. I was originally hoping to use an Edgar salad bowl, but I fear they might be too expensive? Plus, I'm not sure what driver to use. The wrinkle is that folded horn cabs like to cross over around 400-500, which requires a beefy midrange driver. So far, the ones I've looked at haven't been rated below 700-800 Hz.

I've been assuming that I would need a tweeter, as most midrange horns don't seem to be able to cover the whole spectrum. I thought of maybe using a Fostex T90A, if ones could be found affordably enough.

I would of course have to build crossovers as well.

I should add that I have 1981 Cornwalls that could be scavenged if any parts would be felt to be useful to the project. Another thought was perhaps to utilize the Cornwalls as my LF, instead of the horn, if money became an issue. This would also allow me to crossover a little higher if need be (say 500-600 Hz), which would give the project more flexibility. However, I would think it would create quite a disparity in efficiency between the LF and MF/HF, thus requiring additional resistors on the horns in the crossover.

If it helps, my room is about 16 x 16, with a 10 foot ceiling.

I recognize that this a challenging situation, which is why I am looking to the forum for thoughts / suggestions.

Thanks,

Jon

[doityourself]

"For a long time, the thought has been in my head to create a speaker based on the tractrix midrange horn. This is spurred by my dissatisfaction of the resonances and coloration inherent in my Cornwall's exponential horns."

A bass horn is going to have all kinds of resonances and coloration. You'd better keep your Cornwall bottom end and concentrate on the midrange only.

[Guest David H]

I'm not really interested in utilizing the existing Cornwall in any capacity.

Cornwall is a good sounding speaker, and with a little work is really amazing. If you are not satisfied with the bass, you might consider the Crites replacement woofer, I was amazed at how much better it sounded than my 30+ year old original. The midhorn and crossovers would be another worthy upgrade.

Take a peak at the Cornscala threads, this might be just what you are looking for.

[Cornwalled]

Hello again,

What about Greg928gts's Fc260 horn? I see that is a 400 Hz tractrix horn. Again, the concern becomes what driver to use with it? The BMS he recommends is over $500 each, which is way too much. It's a shame you can't use a K-55 with it.

-Jon

[Guest David H]

Hello again,

What about Greg928gts's Fc260 horn? I see that is a 400 Hz tractrix horn. Again, the concern becomes what driver to use with it? The BMS he recommends is over $500 each, which is way too much. It's a shame you can't use a K-55 with it.

-Jon

The Trachorn400 is a 310Hz Fc horn also for use with a 400Hz crossover, but a one inch version and is perfect for the K-55. I saw a pair with crossovers in garage sale for a reasonalble price.