Beryllium diaphragms ??

[JeffW]

BTW, what is the a "Woody Horn"

They are some wood horns made by Woody Banks, slightly smaller but similar to the Yuichi A-290.

[1audiohack]

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

Why sure. In order, aluminum, beryllium, and titainium, all in the same motor.

[1audiohack]

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

Hi Herki;

I have no 2440's. I can't keep the buzz out of the one Be diaphragm in the one 2441 I tried it in. I will put it in another 2441 and give it a go Friday night.

The Woody horns we have that Jeff pictured lets go just below 300 Hz.

Cheers,
Barry.

[Jan Daugaard]

I have tried to invert the colours which makes the graphs more legible. Do let me know if it isn't helpful, and I will delete this post.

It is striking that there is suck-out at 19 kHz, regardless of the diaphragm material.

The graphs are in the same order as above, i.e. aluminum, beryllium, and titanium:

[1audiohack]

It looks better to me. I thought I should just change them to black on white, they are exported in bitmap originally and have great resolution and far better legibility but the files are huge. I should learn more about that kind of stuff but I don't do this kind of thing at all (post measurements and the like) except once in a while here. My apologies, and thanks.

There are more than a few things that interest and puzzle me. One being the 2nd harmonic of the Ti diaphragm beginning at about 7 kHz, the phase response of it (the 2nd harmonic) at that point takes a big jump out of time from that point on up where the other two metals don't, they just follow a relatively smooth curve on out. I have my suspicions but have drawn no conclusions as yet.

[Robh3606]

Nice measurements! In case you missed this I posted the Truextent White Paper in the Technical Reference Section. Might help answer some of your questions. The long and short are Be/Al/Ti in that order. The ribbed Ti diaphrams were the "worst" of the bunch. If you look at the wavelet analysis/waterfall the Al is quite good compared to the Be.

Rob

http://www.audioheritage.org/vbullet...351#post305351

[1audiohack]

Thanks Rob, I did see and read that paper.

Part of what I am doing, besides exploring for fun is to continue to learn to make accurate meaningful measurements, in hopes of improving my own listening pleasures. TEF has many capabilities that I have yet to fully explore. I normally just buzz test, SPL and impedance sweep diaphragm installments and decided to take that a step further and distortion test them to see what you really get should they rub in the gap at all. That kind of led to some of what I posted. I really want to compare the SL's to the standard Ti's. TEF will do all the energy time analysis stuff, display in waterfall as well but if you think the line plots look bad by the time I get them exported, well,,.

[srm51555]

I had a chance to listen to the Yamaha NS-1000’s this weekend. This was my first chance to audition any beryllium material. The main reason for the listening session was to find out when replacing my old diaphragms in the 2440’s, should I go OEM or Be. $1,200 vs $650 is a lot of coin to spend for me on an experiment, and the Be route meant the Altec 846B’s in storage would need be sold. I also didn’t know anyone in the South East Wisconsin area to actually audition a pair of JBL BE drivers, so I figured this would have to do. The Yamaha’s did sound great, but I’ve always been a horn fan. My question is this, if I would switch to Be in the 2440’s would they sound as detailed in the mids of the 1000’s and still have the dynamics of the horn? The system is currently a 2235/2440/2397/2405 with Giskards CC L300 Crossover.