Beryllium upgrade for JBL compression

[sa660]

Can this be done using driver repair parts?
Will Berylium extend the frequencies response of JBL compression drivers and tweeters?

[jimd]

I am on the trail of looking for beryllium diaphragms diaphragms for drivers. The only ones made are in the orient and I am told many are phoneys as there is only one source of real beryllium material. The phoneys are titanium covered with beryllium which is no better sounding than titanium. Working on it, will let you know if I find something, JIM

[frank23]

? why ask twice?

http://audioheritage.org/vbulletin/showthread.php?t=9050&highlight=beryllium

also check out the 4430 Q&D thread where somewhere the difference between the 2431 [aluminium] and 2435 [beryllium] can be found by studying specsheets of the otherwise identical drivers

after searching for a few hours in the excellent Q&D thread, I found them:

http://audioheritage.org/vbulletin/showthread.php?t=3838&page=27&pp=15&highlight=2431+2435

frank

[Guido]

I have contact with the producer.

Before I start the headache with ordering samples and testing I would like to know who's interested. Please PM me.

Beryllium Replacement for the 1" and 2" drivers is available! AND the DCR's are right which is important as "8" Ohm Jbls have a DCR of 3.2 Ohm. All the other aftermarket manufacturers "forget" this!!!

[norealtalent]

My interest would be relative to quality/pricing. I love my 435Be's. I'd love to try some 2" Be dia's in my 2441's. I found an Asian supplier but haven't taken the time to make contact. My 2441 aluminums are great. I can't see gambling a couple hundred bucks on merchandise none of us have any experience with. My guess is interest will be directly proportionate to price.:bouncy:

[Guido]

Don't be afraid! It's my headache. I will do extensive testing and report here.

If they are crap we will forget them fast. If they are nice my interest to import/export them will be price driven also. Believe me;)

And... they don not sell them in pieces :p

[norealtalent]

And... they don not sell them in pieces :p

Come on Guido, you know they're worth more in pieces.;)

[Mr. Widget]

I have contact with the producer.

Before I start the headache with ordering samples and testing I would like to know who's interested. Please PM me.

Beryllium Replacement for the 1" and 2" drivers is available! AND the DCR's are right which is important as "8" Ohm Jbls have a DCR of 3.2 Ohm. All the other aftermarket manufacturers "forget" this!!!Other than the Chinese vendors which may or may not be as advertised, all of the other Be diaphragms seem to come from Japan and Germany. Are you talking with a German or Japanese supplier, or one in China?


Real Beryllium diaphragms are extremely expensive both from JBL and from TAD. I would doubt any diaphragms that are significantly less expensive than those from either JBL or TAD are of the same quality. There are several methods of manufacture which can affect performance and with any high precision parts like diaphragms, careful quality control is essential.

Widget

[Guido]

Real Beryllium diaphragms are extremely expensive both from JBL and from TAD. I would doubt any diaphragms that are significantly less expensive than those from either JBL or TAD are of the same quality. There are several methods of manufacture which can affect performance and with any high precision parts like diaphragms, careful quality control is essential.
Widget

Who knows if the "Beryllium" diaphragms are made from 100% Beryllium? Or is it a Beryllium Alloy? I can't find any description telling it's pure beryllium. I can find descriptions telling from pure titanium.
:dont-know

[Guido]

I'll meet the manufacturer at the music exhibition here in Germany end of march.
So my testing of the beryllium diaphragms will start in April.

[Steve Gonzales]

Other than the Chinese vendors which may or may not be as advertised, all of the other Be diaphragms seem to come from Japan and Germany. Are you talking with a German or Japanese supplier, or one in China?


Real Beryllium diaphragms are extremely expensive both from JBL and from TAD. I would doubt any diaphragms that are significantly less expensive than those from either JBL or TAD are of the same quality. There are several methods of manufacture which can affect performance and with any high precision parts like diaphragms, careful quality control is essential.

Widget I've recently tried to get the scoop on the chinese dia's. I tracked down and spoke at length to one of the fabricator/ consultants to JBL. He is very well known in that circle. He said the well known chinese dia's are fakes, basically painted titanium!. He also enlightened me about the different manufacture processes. He said the best and most difficult is the forming of the dia. from Be. foil, ala JBL. He said that the second best in his opinion is what is called "sputtering". This process involves a 'vapor deposit' method ala JBL 066 1" dome (see L166 lit. in the library). They take a copper former and 'sputter' the beryllium onto this copper former and then etch the copper off, leaving the beryllium diaphragm. A well known company uses this type. He said that the difference between the two is akin to having forged pistons vs. cast pistons in an automobile engine, respectively. Both are fine, but one is better in his expert opinion. Guido, I hope this information will help you at that meeting and I look forward to reading your impressions, Steve G

Edit: His quote of one process being better than the other, in context, was regarding the structural absolutes. This is in no way saying that, given that there are other variables, such as, overall driver design characteristics and execution, one should sound better than the other. S.G.

[Ian Mackenzie]

The source I had an email from was Taiwan, if that is the case they have the resources so anything is possible.

JBL were'nt the first to market with Be and I think this will end up like the well established after market for Ti in time.

[4313B]

He said the best and most difficult is the forming of the dia. from Be. foil, ala JBL. He said that the second best in his opinion is what is called "sputtering". This process involves a 'vapor deposit' method ala JBL 066 1" dome (see L166 lit. in the library). They take a copper former and 'sputter' the beryllium onto this copper former and then etch the copper off, leaving the beryllium diaphragm. A well known company uses this type. He said that the difference between the two is akin to having forged pistons vs. cast pistons in an automobile engine, respectively. Both are fine, but one is better in his expert opinion.The JBL foil is superior AND it has the added benefit of not killing you. :rotfl:

[hapy._.face]

...AND it has the added benefit of not killing you. :rotfl:

That's always a good selling point. :o:



Guido-
I can't wait to hear the results of your testing. If they are decent- sign me up for a pair!! Maybe several!

:D

[Steve Gonzales]

The JBL foil is superior AND it has the added benefit of not killing you. :rotfl: Didn't Roberta Flack sing: Killing me softly with his song?. :D

[Guido]

Guido, I hope this information will help you at that meeting and I look forward to reading your impressions, Steve G

Yep! It helps me a lot.
We will easily see from the response graphs what they are doing.

I have the promise from my carpenter that my 4435 will be finished in April. So I'm set up to do listening tests with
2426 JBL Ti
2426 JBL Alu
2426 Aftermarket Ti
2426 Aftermarket Alu
2426 Be
2435 JBL Ti
At least this taiwanese company manage to get the DCR right (3.2 Ohms). Any other Aftermarket dia I measured was in the 4 to 5 Ohm area.

Additionally I will get Be's for my 2441. But I'm still waiting for my Westlake Clones from Matthias.

[Guido]

Back from the music fair in Frankfurt I brought some samples from XKonkord/Taiwan.

Unfortunately the 44mm Be dia was damaged when touching it during presentation so I got a dia with wrong surround. Other will come.
The DCR's also do not match bt I have the promise that my main order will be right DCR. Well we'll see.
Testing need to wait as I'll be in China whole next week (the trip has nothing to do with speakers :) ). So far they fit perfect which I tested yesterday.

"D16R2425Be" should be 6.9 ohms but is 5.9 ohms

See the 44mm VC pics here.
I'll start another thread called "asian dias" with pics of the other samples I've got.
http://www.audioheritage.org/vbulletin/showthread.php?t=10180

[Guido]

See pics

"D16R2441Be" should be 7.9 Ohms but is 6.8 Ohms

[Zilch]

"Dimple" surround, apparently.... ;)

[jimd]

I guess I must disagree with your desired voice coil DCR.

Impedance of a driver needs to be expressed in MINIMUM impedance, NOT average or peak. To say a 3.2 ohm DCR voice coil is 8 ohm is simply not true, it will be about a 4.5 ohm load.

The impedance "conversion" ratio reflects the magnetic flux in the gap. The higher the flux, the greater the ratio. 22 KilloGauss is the maximum that can be acheived and at that point, the maximum conversion ratio for minimum impedance is 1.45-1.5. HF Drivers with lower flux density, like most with 1.75" voice coils can have conversion ratios as low as 1.3-4.

Sure, those drivers with lower DCRs appear louder, they are simply drawing more power, can possibly endanger amplifiers and will upset crossover frequencies.

Proper DCRs for minimum impedance are 5.5-6.5 ohms for 8 ohms, 11-12.5 ohms for 16 ohms, depending on the flux desity in the gap. In the 1970s this was quite controversity in the Pro Audio spectrum and resulted in manufacturers, including ALTEC and JBL changing their voice coils. In the later's case, several 16 ohm units were relabeled as 8 ohm. Seems to me, that right now no one appears to be watching.

I like the idea of a possible source for Be diaphragms, just want the DCRs to be right to properly work in vintage drivers, many of us won't buy any that aren't.

By the way, I am told, the JBL Berrylium diaphragms are Be/Al alloy, which seems to work fine.

My 2 cents, JIM

[Guido]

Thanks for input Jim. Before I answer you should know that I'm an electrotechnical engineer and into JBL for more than 20 years. I'm well aware of the differences between DCR and impedance.

The older 8 ohm rated JBL Drivers have an DCR of 3.2 ohms doesn't matter what you mean.
The older 16 ohm rated JBL drivers have an DCR of 8 ohm. Some very old 16 ohm drivers have an DCR of 10-11 ohms

Hope that helps to clear things up.

[Guido]

By the way, I am told, the JBL Berrylium diaphragms are Be/Al alloy, which seems to work fine.

A lot of rumours are circling about this. I also do not believe in "pure" Be. The samples I got are an alloy also.

[northwood]

:)

[jimd]

Again, I repeat, there is no possible way a 3.2 ohm VC can have a 8 ohm MINIMUM impedance, same as an eight ohm DCR cannot be a minimum 16 ohms in a driver. Just because someone says it is, does not make it true.

In the 1970s drivers with voice coils that were below their rated impedances resulted in a lot of the early direct coupled solid state amplifiers expiring prematurely. The fragile nature of these amplifiers simply would not tolerate overloads, especially when driven to close to rated output. Previous tube amps and current solid state amps were/are able to tolerate greater overloads.

Two good examples of this are the ALTEC 802D and the JBL LE 85.
The "16" ohm VC of the 802D was 9 ohms DCR. When ALTEC redesigned the VC to minimum 16 ohms, it came out about twelve ohms DCR.
The LE 85, whch was labeled 16 ohms has a VC DCR of about 6.7 ohms. In the 70s they relabeled the driver, with the same Diaphragm/VC, at 8 ohms, just about right.
Further the 802D and the LE85 are very similar in construction, same voice coil size, diaphragm suspension, diaphragm radius, same phasing plug, same acoustic length, nearly identical and in some cases, identical magnet. The LE85 does have a larger and more efficient magnet return structure, however this could never amount to much difference in rated impedance. I used these two drivers as examples as I have both. A LE 175 would have been a better comparison as it is magnetically identical to the 802, but I don't have one.
Later drivers with different magnet types and topology operate under the same laws of physics these drivers do so ratings will be similar.

I personally do not care what someone says something ought to be, merely that the driver is as it is rated, an honest 8 or 16 minimum ohms impedance. Anything else is patently missleading. Jim

[Guido]

REAL DCR=8.0 Ohms.
Testing will start this weekend.

Quality of new Kapton Voice Coil looks excellent

[Guido]

REAL DCR=3.2 Ohms.
Testing will start this weekend.

Quality of new Kapton Voice Coil looks excellent, now diamond surround :bouncy:

[JBLnsince1959]

:bouncy:

Looks GREAT!!!

Can't wait to hear how they sound:D

[Maron Horonzakz]

The variation in diamond pattern size is interesting. also the beaded pattern to extend hf response. This will effect compairison between authentic JBL and clone units.;)

[Guido]

The 44m (2426) Beryllium Dias are fakes!
Original D8R2425 measures better. :(

Testing of the 100m types in 2441 core will follow when my Westlake clones are finished.

[Zilch]

Fake in what respect, Guido?

Are they not Be?

What difference were you expecting to see?

The FR plots don't reveal much definitive, from what we saw comparing 2431 and 2435:

http://audioheritage.org/vbulletin/showpost.php?p=63324&postcount=69

The difference would be in the sonic quality, I would think.... :dont-know:

[Guido]

I don't believe they are Be. It looks like they have a higher moving mass then the Ti's.
The rolloff starts not later than with the Ti's.

My 2435 show clearly more HF extension and need far less HF boost then 2426. Thats what I expected. I don't like what the HF Boost of the 4435 network does with the 2426 at high levels. With the 4435 more than with the 4430 JBL really push the last out of the 2426!
I'll go deeper into this in my "4435 cabinets arrived" thread soon.

[Ian Mackenzie]

For clarity the 4430/35 passive eq is a cut not a boost but the Q factor of the series capacitor and inductor C9 & L1 does have some real gain at resonance of 16 khertz.

The parellel resister across the signal R5 (10R) in the 3135 raises (7.5R in the 3134) the level overall to match the 2234H @ 96 db without the mass ring.

Ian

[Guido]

For clarity the 4430/35 passive eq is a cut not a boost but the Q factor of the series capacitor and inductor C9 & L1 does have some real gain at resonance of 16 khertz.

The parellel resister across the signal R5 (10R) in the 3135 raises (7.5R in the 3134) the level overall to match the 2234H @ 96 db without the mass ring.

Ian

Thanks Ian. That's what I wanted to say.
3135 gets more out of the driver than 3134.

[Bruno GINARD]

I have received 2 pairs of 99' diaphragms from Konkord last friday.Unfortunately 2 of them were broken by the freight ( see the pic)....KOnkord seem to be a very serious company, i was called by the DHL Worldwide french agency several hours after a mail to Tiapei about the problem to resolve it !

I am going to try those diaph. in several weeks, because i am at the end of the modifications with my filter and don't want to mix several tests at the same time.( filter tests : simple is beautiful ! i'll post a thread after testing.............)

Apparently it IS Berrylium....fragile like glass, and the same particular colour i have found on my TAD 4001...I understand now why the TAD had a grid to protect the diaphragm.

to be continued.........

[Bruno GINARD]

pic.........

[Mr. Widget]

How much are the 4" Be diaphragms

Has anyone listened to them yet?

Could you please post the contact info here?

I'm sorry if any of the answers have already been covered...
Thanks.


Widget

[Guido]

Widget,

they are incredible cheap! Prices with PM

What is expensive is the small order surcharge for orders less than 1000 USD which is 100 USD plus the shipping app. another 100USD. So it makes sense to collect orders.
I paid all the surcharges for first order as I want to sell these dias here in Germany and needed testing samples. But next order MUST be bigger.

The delay of 2 month was created as the first samples handed over at the frankfurt music fair where wrong DCR. But this time everything is right. I'm especially satisfied with the Aftermarket Ti and Al dias, both 4" and 1,75". They look and measure excellent (see http://www.audioheritage.org/vbulletin/showthread.php?t=10180&page=2). But listening tests take more time.

[readswift]

This process involves a 'vapor deposit' method ala JBL 066 1" dome (see L166 lit. in the library). They take a copper former and 'sputter' the beryllium onto this copper former and then etch the copper off, leaving the beryllium diaphragm. A well known company uses this type.

TAD :> I saw picturse of the fake dia.-s on the Beryllium professional company's site, great forum here, thanks everyone I love collectin bits like this!!!

[Robh3606]

The guys in the US who do JBL's diaphrams. I would be very suspicious of "cheap" beryllium

Rob:)

http://www.berylliumproducts.com/Acoustics.aspx

[Elac310]

I have received 2 pairs of 99' diaphragms from Konkord last friday.Unfortunately 2 of them were broken by the freight ( see the pic)....KOnkord seem to be a very serious company, i was called by the DHL Worldwide french agency several hours after a mail to Tiapei about the problem to resolve it !

I am going to try those diaph. in several weeks, because i am at the end of the modifications with my filter and don't want to mix several tests at the same time.( filter tests : simple is beautiful ! i'll post a thread after testing.............)

Apparently it IS Berrylium....fragile like glass, and the same particular colour i have found on my TAD 4001...I understand now why the TAD had a grid to protect the diaphragm.

to be continued.........

Hello Bruno and others,
Sorry for digging out this old thread. Are these Be diaphragms with diamond pattern surround still produced/sold by Konkord (or someone else)? Couldn't find any info on this manufacturer anywhere.

[Bruno GINARD]

Hello Bruno and others,
Sorry for digging out this old thread. Are these Be diaphragms with diamond pattern surround still produced/sold by Konkord (or someone else)? Couldn't find any info on this manufacturer anywhere.
Hi all

i am back on the forum after years....thank you Elac310 for posting !

the konkord didn't sounded bad , but several months after ( the original message ...) I have tried Radian models and they're still in service .
A friend of I keep them with is 2440 in 4350 monitors speakers ( but the cut off is higher than 500hz)...

the next try will be with truextent models I have bought to John Wolff at classic audio repro , JW told me that I was possible to use them with a 6db slope at 500 hz on the Hartsfield ..... To be continued because I am rebuilding my hartsfield with several mods.

about Konkord...apparently the company has totally disappeared from the web , maybe the market ! Or the name changed and they are still an OEM provider for cones ...

[more10]

You can get Truextent for JBL 4 inch VC drivers. I don't believe the 1.75 inch VC drivers will get beryllium diaphragms because of the phase plug shortcomings.

[fpitas]

You can get Truextent for JBL 4 inch VC drivers. I don't believe the 1.75 inch VC drivers will get beryllium diaphragms because of the phase plug shortcomings.

The Radian 1" exit drivers with 1.75" VC are now available with beryllium diaphragms; so if those diaphragms fit JBL drivers (as the 4" VC Radian diaphragms do), then the answer is "yes". Well, assuming one can buy the diaphragm without buying a Radian driver.

[more10]

These diaphragms "only" fit Radian drivers. These are modern drivers with very good phase plugs. Made in the USA :-). A friend of mine has a pair of 475PB with beryllium, I will very soon get a report on how they sound.

[fpitas]

These diaphragms "only" fit Radian drivers. These are modern drivers with very good phase plugs. Made in the USA :-). A friend of mine has a pair of 475PB with beryllium, I will very soon get a report on how they sound.

I was using the Al diaphragm 475PBs for a while before I got the TADs. A nice sounding driver for the money, although it struggled a bit down near my 800Hz crossover. The extreme highs could also sound a bit scratchy, which I assume the beryllium will fix.

[Elac310]

@Bruno and more10

The reason why I asked is that I've tried a 4" Be diaphragm with flat surround in my 2445.
I would now like to try 4" Be with diamond pattern, which I know from my original JBL 2445 diaph's.

I understand JBL do not sell their 4" Be and in any event, they might not fit into the 2445. Hence my interest in anyone else doing such dias.
If anyone has a tip...

[ivica]

@Bruno and more10 The reason why I asked is that I've tried a 4" Be diaphragm with flat surround in my 2445. I would now like to try 4" Be with diamond pattern, which I know from my original JBL 2445 diaph's. I understand JBL do not sell their 4" Be and in any event, they might not fit into the 2445. Hence my interest in anyone else doing such dias. If anyone has a tip...

Hi Elac310,

I have measured 2445 with the original Ti-no-rib diaphragm, and Be-(Truextent), with my 2"-horn JAN45-2
It is visible that the 'ringing' (not smoothed curve) of Ti diaphragm is more pronounced then Be.
Even Be diaphragm has several dB larger output from 3kHz to 10kHz.
But with Ti diaphragm almost 20kHz can be reached.

Reagards Ivica

[ivica]

Just as an info:

Truextent® Is Introducing A New Metal Matrix Composite (MMC) Dome and cone Material:
http://materion.com/TruextentNewProducts
"..TF-25™ is a new proprietary acoustic material from Materion that delivers superior performance over current materials. Available at a price point lower than our Truextent Genuine Beryllium material, our new TF-25 material has been developed to satisfy the demand for premium performance at a reduced cost....."

But we have to what would be the real consequence on the market

regards
ivica

[baldrick]

Anyonw know what is the dirrenece between the "old" Truextent Beryllium and the new BeX version (http://materion.com/Products/Beryllium/BerylliumAcoustics/TruextentBeXDiaphragm.aspx)?

[Mr. Widget]

Anyonw know what is the dirrenece between the "old" Truextent Beryllium and the new BeX version (http://materion.com/Products/Beryllium/BerylliumAcoustics/TruextentBeXDiaphragm.aspx)?See post #15 in this thread (http://www.audioheritage.org/vbulletin/showthread.php?36128-Truextent-Dias).


Widget

[baldrick]

Thank you Widget!!

[Champster]

I thought this was a pretty important quote from the press release.

"Finally, we compare the new Truextent TF-25 dome to one made from Truextent Genuine Beryllium. As expected, the Genuine Beryllium dome out-performs the TF-25 dome."

Of course, the cost is lower for the TF-25, but if you're out for all out performance, the Be is still King.

[brettMc]

Hi All,

was there ever a consensus arrived at on beryllium upgrades to the ti tweeter?

i have a pair of 4312as I am attempting to upgrade.

thanks,
brett