• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Beryllium diaphragms for JBL drivers.

saabracer23

saabracer23

AK Subscriber
Subscriber
I’m thinking I want to try to take the JBLs I have to the extreme. Does anyone know if there are beryllium diaphragms for the 077 tweeter and LE85 mid (Summit)? Would the diaphragm from the TAD ET-703 fit the 077?


It would also be interesting to try the same thing on my XPL200As with the dome tweeter and 3” dome mid, they’re titanium right now.

Dan
 
Register to hide this ad
I wouldn’t touch the XPL drivers. Likely to not improve them. The mid driver you have in them is extraordinary.
 
Last edited:
Last edited:
My 2-cents...

(disclosure: I own some TAD 4002 drivers with the BE's)

Heard the same horn with the stock driver verses the TAD 4002 driver.

Side by side, it's pretty easy to tell a difference. I think blindfolded I could probably get it right 104% of the time. There is a noticable clarity with the BE. I don't know though, if I walked into your room I'd be able to say "Ah HAH!!! You (do or do not) have BE's in those speakers!!!"

Perhaps someone else could but for me the difference WAS there, but more to a degree than transformative.

I'd wonder if there are better bang for the buck things you can do (room treatments??)
 
I just checked on the price for Radian Beryllium Diaframs for the Large format 2" drivers, 2440's-375's ect, $988. each. I didnt see any for the 1" Drivers.
 
Nyjblbob said:
I just checked on the price for Radian Beryllium Diaframs for the Large format 2" drivers, 2440's-375's ect, $988. each. I didnt see any for the 1" Drivers.
Click to expand...

Yeah, on the Radian site I saw a 1" driver with a beryllium diaphragm but not a 1" beryllium replacement diaphragm for Altec or JBL.
 
All metal diaphragms resonate. So I would be worried about how to dampen those resonances when chnging from one material to another. Every one wants to extend the frequency range and the power handling but having a nasty peak in the audible spectrum is not my idea of a good result. Its like replacing a woofer with a differenct cone material with out retuning the port or reflex opening.
 
We made the machines that rolled the beryllium to the correct thickness +/- a few microns....

It's an expensive process but even more so due to the safety precautions required to protect the workers and environment.
 
twiiii said:
Every one wants to extend the frequency range and the power handling but having a nasty peak in the audible spectrum is not my idea of a good result.
Click to expand...

The point of extending the frequency range is to push the distortion out of audibility. If the peak in response isn't due to nonlinear distortion, and doesn't have directivity problems, it's usually easy enough to compensate.

twiiii said:
Its like replacing a woofer with a differenct cone material with out retuning the port or reflex opening.
Click to expand...

All other things being equal, why would woofer material have any effect on port tuning? Material choice has most effect on break-up at high frequencies - which frequencies and how bad. Cone materials only differ in the bass region by how strong they are, and how much they weigh. The latter affects the Mms Thiele-Small parameter, which is the sum of all the moving mass. The strength of the cone can matter if the alignment makes strong physical demands. Not all drivers can survive high power in a tapped horn design.

But any particular strength or weight can be achieved with any cone material. It's achieving both simultaneously that can be difficult - especially *stiffness* vs. weight. That's the advantage of beryllium, where the high stiffness and low weight push break-up resonance so high in frequency as to be inaudible. Hopefully nobody is pushing a woofer into its break-up region? And hopefully nobody is tuning a port or vented enclosure up to that higher frequency!
 
Last edited:
saabracer23 said:
I’m thinking I want to try to take the JBLs I have to the extreme. Does anyone know if there are beryllium diaphragms for the 077 tweeter and LE85 mid (Summit)? Would the diaphragm from the TAD ET-703 fit the 077?


It would also be interesting to try the same thing on my XPL200As with the dome tweeter and 3” dome mid, they’re titanium right now.

Dan
Click to expand...
Maybe a little late to the conversation, There are no Be Diaphragm replacements for JBL 1" Throat Drivers. If you are not prepared to go to a 2" throat Driver. Radian 1" Be fitted drivers are the best bet.
Materion manufactures all the Forged Domed Be Domes for assembly builds by various speaker manufacturers. Materion previously manufactured only one complete unit to fit only JBL 2" format drivers.
They have now sold that process to Radian, who as of this date has not produced 1 Diaphragm assembly. Radian's 950 Be Dia. will fit a JBL 2" format Driver with good results, but will be bettered by a Materion built
Be or BeX 4008 &4016 Dia. We can only hope Radian gets it right when their product finally arrives.
The TAD Et-703 is now out of production for quite some time, Prices when sold on the used market are very high. Diaphragms are unique to only the ET-703, and have been unavailable now for over 10 years.
Beryillium improves any system with detail and high frequency extension.
JW5115
 
When the 2" JBL BE Diaphragms were available. they were $780+ each. I understand they have dried up. NLA
I believe the Co was Truetextant. or something similar
 
Last edited:
I ran the 4" Be 4016 diaphragms in horns with the ET-703 up above. The Be phragms don't have great high frequency extension, so I ran a tweeter. Then when it started getting warm, I changed to coated 16 ohm Ti phragms and no tweeter and let the 4" run on out on the top. I prefer the coated Ti (which are also NLA now in 16 ohm version), but I'll fool around more when the weather starts getting cool again.

And yeah, the ET-703 is a little compression driver, the 077 is a ring radiator. Absolutely no chance of interchanging parts there
 
Yeah, as mentioned I have Be tweeters. But in 4" diaphragms, they don't go as high (cleanly) as the coated Ti. I don't have time to dig up the posts/threads right now, and by all means don't let me dissuade you from running 4" Be phragms.

Many of the guys running 4" drivers as 2 ways at LHS have reverted back to coated Ti, where Be works good in a 3 way. That said, I'm not sure I won't leave the coated Ti in when I go back to 3 way.
 
I perfer the titanium ones. Most people can't hear above 20khz so Berillium headroom extension not really needed
 
You must log in or register to reply here.
Back
Top Bottom