Fast and detailed midbass unit

[Rocky]

I am currently building a horn system powered by a single watt SET. 600Hz-5000Hz is covered by TAD 4001, and support above 5000Hz will be covered by a fane HF driver..

Now, for space savings, I will not yet go for horn loading on frequencies below 600Hz (2-way active XO at 600Hz).. The usual midbass driver choice in horn setups are high efficiency 10''-15'' paper coned JBL or TAD drivers, but I am concidering something quite unconventional; an Accuton ceramic driver.. The 7'' C94, in a closed box, covering the frequencies from 100Hz to 600Hz. It's impedance of 8 ohms is perfect, and 89dB/w/m is also acceptable, though I will need some push/pull type amp to drive it.

I am hoping that the incredible stiff membrane of the Accuton, and it's piston-like movements, will preserve a high level of detail from where my mid-horn rolls off.. but how will it integrate?

Anyone with any ideas or thoughts on this?

[454Casull]

The Seas W22EX is, I think, a better driver than the Accuton C94.

http://www.linkwitzlab.com/x-mid_dist.htm

Linkwitz tested the W18E, but he believes that the W22EX should be even better because it can move more air.

To recap, the W18E has excellent burst performance under 1kHz, and the W18E showed the least amount of non-linear distortion at 150Hz. Out of all the drivers tested, the W18E is pretty much the best one is used under 1kHz.

But, the sensitivity is only 87.5dB.

[Rocky]

I have auditioned a special custom made long-throw version of the W18EX both in 2-way (DynaBel SuperExact, mated with SS9500 alu.dome), and in d'appolito (DynaBel Euforia, mated with SS revelator) in DynaBel's listening room, and while they both are impressive speakers, I did not find the Seas Excel midwoofers to be particulary great compared to what I've heard from Mårten Design's comparable line of speakers using Accuton drivers (Miles, Monk).

The DynaBel speakers I mention are very HQ, and the designers/developers at DynaBel have worked with Seas for ages (both are norwegian companies) and probably know the Seas drivers better than Seas themselves, so I don't think I have gotten a negative impression of them from a bad speaker design either..

With all due respect to mr. Linkwitz, I do not think his measurements and ratings will have any significant value in my choice of drivers.. What I am more curious about is possible problems with the integration between the compression driver horn and the accuton midbass at my XO freq at 600Hz.. As well as workarounds and tips to get the best out of such a driver in such a system..

And ofcourse opinions wether this is a really dumb idea or not..

[Greg B]

I think it's really a dumb idea.

There are reasons that mid/hi pro type horns are commonly mated to 12 or 15" high efficiency drivers. First, the polar patterns at the crossover frequency aren't going to match up well with a small driver. IMO, this will create a audible disconnect and weird power response. Second, with that sort of efficiency mismatch, I just can't imagine that the lows and mids won't sound much more compressed than the highs, especially with very different amplifiers. You never know, it might work, but I doubt it. Obviously I think that going with a high quality 12 or 15 is more sensible.

If you're hell bent on an exotic 'hifi' woofer, I think a 12" or larger Focal Audiom W coned type would be the way to go.

Greg B

[Rocky]

Originally posted by Greg B
If you're hell bent on an exotic 'hifi' woofer, I think a 12" or larger Focal Audiom W coned type would be the way to go.

No, I'm not hell bent on anything.. I think I'd rather go for a high efficiency paper cone than a focal actually.. At the moment, I'm just playing with thoughts on what to do with my lower end.. As I've already started the upper end without any clear plan on what to do downwards.. Exept that I want an japanese Ale or Goto bass compression driver with mega horn when I win a lottery.. Wich will never happen as I very rarely buy lottery tickets...

Thanks for your thoughts, Greg.

[roddyama]

I don't know if you've seen this thread or not, but the TAD 1102 looks like it would work pretty well. I don't have any personal experience with this particular driver, I know the TAD products are high quality.

I'm using dual JBL LE10A's from 70Hz to 1200Hz powered by a Bryston 4B-ST. It does a very good job. It blends well to the TAD 1601a subs and the TAD 4001 / McCauley 451 horns on top. The voices sound natural and uncompressed, and the percussions are sharp and dynamic. I have thought about changing the mid-bass, but now it would be to get more of what I have with the JBL's.

[Frode]

Originally posted by Rocky



No, I'm not hell bent on anything.. I think I'd rather go for a high efficiency paper cone than a focal actually..

This is probably the best thing you can do. I don't think mating a horn with a 'regular hifi' driver is a good solution, even for space saving.

Frode

[Duck-Twacy]

PHL?

[Rocky]

Originally posted by Greg B
First, the polar patterns at the crossover frequency aren't going to match up well with a small driver. IMO, this will create a audible disconnect and weird power response.

Originally posted by Duck-Twacy
PHL?

Is PHL's high efficiency 6.5'' drivers (coax or mids) a good alternate? or will it too "create a audible disconnect and weird power response" ?

[Frode]

I'm not an expert, but I think the polar patterns depends on the size of the driver. A 6.5" is not the best choice with a 600Hz XO. I was told that a 15" works well around 500Hz and a 12" around 1000Hz.

Frode