Beryllium upgrade for JBL compression

[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/vbullet...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.