Beryllium diaphragms ??

[richluvsound]

I'll just go back to my saw dust

Thanks for popping in to clear that up . !

Rich

[maxwedge]

They sound really nice is about the best I can put it!
I have mine in 2445's w/2385 horns and a 630hz x-over. I like the lower crossover much better than 800 with my system. The mids are 2206 with 2404 on top at 8k. I tried 3way but they dropped off fast ~10k, but then I wasn't using any compensation for my CD horns when I measured them, so I think I'll try 3way again!

Re-configured for 3 way with some HF compensation on my 2385 horns and finding it very enjoyable.
X-over's @200 and 630 w/2245, 2206 and 2445

[pos]

Still running without tweeter?
What crossover machine are you using?

[Oldmics]

Inquiring minds want to know.

Any documentation if so?

Thanks,Oldmics

[richluvsound]

Guido posted graphs somewhere on here !

[maxwedge]

Still running without tweeter?
What crossover machine are you using?

Yep, 2404's in the closet for now. I doubt I can hear over 16k anyway...53 here!
It's a Rane AC-24 digital unit. Basically it's a stereo 4way dsp that uses knobs. No pc interface.
http://www.rane.com/pdf/old/ac24dat.pdf

[1audiohack]

OK I finally got around to it, I loaded three 2441's with new diapragms, one Al, one Ti and one Be. All have new JBL foam in the back caps. The Ti and Be are 8Ω, the Al is 16Ω. I ran them all at 300 Hz and got them all centered, the Be was a real fight to get centered.

I wanted to try to isolate some wiggles and ripples so I impedance and SPL swept them all open back, then with the back covers on, on the bench pointed up, with a metal cap over the mouth, with a rag stuffed in the throat, open throat no horn, with a 2311, and with a 2397.

I don't want to wash this post with measurements no one is interested in, in short, the 2397 is done at 11.5 kHz no matter what's driving it and the 2311 measures flattest with an Al phragm going decently to 16 kHz. The Be is the best behaved of them all with the smoothest SPL response curves, the HF SPL extension is not substantially enhanced, it is smoother though.

I am not going to tear down this test setup yet because JeffW is sending a pair of D?R2450SL's to measure, I will load them into other 2441's so they will all be available if we want to check anything else out.

I really don't think I will put the 2397's in a system as I have better horns, and pretty much everyone that has compared the Be's to the rest already knows, it's old new.

I will post anything anyone is interested in seeing, just shout out.

All the best,
Barry.

[JeffW]

?=8

[JeffW]

I don't want to wash this post with measurements no one is interested in, in short, the 2397 is done at 11.5 kHz no matter what's driving it

While I'm crossing mine out at 8KHz, I'm still interested in what the throatless 435AL and fabulous plywood adapter will do. So keep that rig handy until I get some more of those flanged up. I've read several posts saying ~12K is as good as it gets, but AFAIK nobody has mounted a throatless driver yet.

[Mr. Widget]

While I'm crossing mine out at 8KHz, I'm still interested in what the throatless 435AL and fabulous plywood adapter will do. So keep that rig handy until I get some more of those flanged up. I've read several posts saying ~12K is as good as it gets, but AFAIK nobody has mounted a throatless driver yet.

I made an adapter and tried a TAD TD-4003... not throatless, but much closer geometry to the small format JBLs than the old WE based 2441 geometry... the results were not at all good. There was a real mismatch at the lower end of the spectrum.

Thanks for the commentary and sharing your findings Barry.


Widget

[jerv]

OK I finally got around to it, I loaded three 2441's with new diapragms, one Al, one Ti and one Be.....
.....I am not going to tear down this test setup yet because JeffW is sending a pair of D?R2450SL's to measure, I will load them into other 2441's so they will all be available if we want to check anything else out......

I will post anything anyone is interested in seeing, just shout out.

All the best,
Barry.

I'll shout!
This is very interesting, Barry. I use my 2445's with 2450SL's. I am very pleased with them, but wonders if it will be worthwile to change to Be diaphragms.

Please post your findings!

Regards, Espen

[1audiohack]

As requested, a Woody horn on a 2450 with 8Ω Be's, on axis at 0.6V at 2 meters. These don't come over well as a jpeg, the yellow line is the second harmonic at an average of 41 dB below reference, the blue line is the 3rd harmonic.

[pos]

Thanks Barry!
Could you please post the same measurement for the two other diaphragms types, for comparison?

[herki the cat]

As requested, a Woody horn on a 2450 with 8Ω Be's, on axis at 0.6V at 2 meters. These don't come over well as a jpeg, the yellow line is the second harmonic at an average of 41 dB below reference, the blue line is the 3rd harmonic.

Barry, I have some 2440's. If you have 2440, many of us would appreciate Be' curves on your Woody Horns. If not, 2441's with Be' will do. The 2440 has higher flux density of 20,000 compared to 18,000 of the 2441 which provides significant high end improvement in 2440.

BTW, what is the a "Woody Horn" Can you tell me the lowest frequency it provides full acoustic loading.

Regards, Herki

[Eaulive]

These don't come over well as a jpeg

Try ".gif", you may lose some colour range but you will keep the resolution and detail, the file will be smaller too.