JBL goes Berryllium

[LICORNE]

quote:

Its 045Be-1 ultrahigh-frequency driver uses a 1-inch beryllium diaphragm and 2-inch neodymium magnet to produce frequency response beyond 50kHz. The 476Be high-frequency compression driver utilizes a 4-inch, pure beryllium diaphragm with a 4-inch aluminum edge-wound voice coil, and JBL's rapid-flare, coherent-wave phasing plug. A high-efficiency neodymium-magnet motor structure features refinements such as a pure copper-sleeved polepiece that maintains maximum magnetic-gap flux and delivers superior sound quality at any volume, with exceptional clarity and resolution,


....................

[Tom Brennan]

A pal uses those be diaphragm JBL 2435 drivers that come up on ebay from time to time, I'll tell ya, I never heard better.

[Old Guy]

JBL has been using Beryllium for some time.

Their production methods are a bit cruder than TAD's though.

TAD uses vapor depositing, JBL AFAIK does not, they use mechanical forming. I would think the TAD system would result in a better part.

I have only heard a couple models from JBL, they seemed fine- but it was a one night listen in both cases, and I had no control over the program material.

The TAD driver still sounds best, the aluminum 288=G is a close second. The Beryllium JBL's come in somewhere after that.

MY only issue with TAD is just the price- I could buy 288 G's and a couple of really nice old McIntosh amps for less than a pair of TAD's

Personally I'd grab the Altec's and Mac's- they ain't making anymore of them. I can get new TAD's if and when I want to. Your mileage may vary.

[Old Guy]

Scotty I appreciate the clarification. I had a couple hour discussion one night at a local pub- "local" for my apartment in town is Ohio State University with a large engineering college.

To boil it down, they were saying with vacuum depositing you can control thickness to less than a millionth of an inch. Pretty incredible. You can also vary the thickness- say if you want to make the suspension thicker than the dome.

But the equipment is expensive, requires constant maintenance, and a skilled operator. Which is why it isn't more common.

I concede the TAD's superior high end, and what I would call "impulse" or transient response.

The 288-g is a bit better in the mid, as you say.

I suspect that is the beryllium/aluminum difference.

I agree Alnico is smoother- it is making a comeback. On a strength scale, neodymium is cheaper than Alnico. Which is why there is so much neo around.

Some smart investor could probably do well- the Soviet union is s******** lots of cold war military gear. It is the cheapest place in the world to buy Alnico right now. You can buy Alnico 5 as a scrap grade by the pound or kilo. If I hadn't bought the place in the country I wanted to buy a couple containers- I think it may be a better future than precious metals.

But hey- at my age I need 64 acres in the country more than I need a couple containers of Alnico. Can't go fishin' with Alnico.

I would love to talk TAD into making a diaphragm for the 288 G or especially the H- yeah, same I know. I bet $50 the 288-H with Tangerine would beat the TAD. Oh well- those are the kind of thoughts you get when you get old.

[scott fitlin]

What happened with me, is that I found that the extended HF response to be too much in my particular application. I run a three way full range, 15,s 2in compression driver on JBL 2395 horns, and 2404 bi radial tweeter.

With the JBL 2441 or Gauss HF 4000, the lower HF response seems to give me a more focused sound in the 800hz to 7K range, and with the TAD 4002,s on my horns, the extended response caused the sound to become excessively bright and I had too much overlap between the horn and tweeter. So, I changed my slopes from 18db Butterworth to 24db L-R, but still I didnt like it.

Conversely, on a TAD AFAST horn, in a 2 way arrangement, 15,s and horn running all the way out to 20k, I liked that MUCH better with the TAD drivers.

If I put my Altec 311-90,s with 288-16G,s basck in here, THAT has a sound, something special also, only Altec had. My JBL horns and drivers are very percussive, and dynamic, the Altec horns and drivers have a certain openess, and sweetness, allowing me to achieve a very lush sounding midrange. This was that 70,s sound I grew up on, and to my ears, even though I do love vintage JBL too, only the Altec stuff had this paticular tonality. At that time we used to use the 808,s, alnico with Al phragms and tangerine phase plugs on small Community fiberglass horns as tweeters. It was the most open, and golden sounding MF/HF. Very symphonic sounding, and I have been toying with the idea of converting back to that gear.

The only other compression drivers I liked on my horns, and in this room, were the Gauss HF 4000,s. Similar to the JBL 2440, but sweeter, female vocals really shine through them.

I guess I am spoiled, I grew up on the BEST of the BEST, what always amazes me, even to this day, is how the best of the vintage stuff sounded so sweet and mild, yet dynamic, but so lucid and clear, really extremely focused in just the right ranges. Still today, much of this older gear makes a natural, realistic sound, that none of todays drivers can match, IMO. Each brand had its own unique and distinct tonal shape and character, and they sounded sweet, and todays drivers offer extreme attention to microscopic detail, but tend to sound analytical, and very extended but not musical.

I find I would rather hear well recorded brass sound burnished, and crisp, with just the right amount of bite, like brass really sounds, than hear the same recording sounding very exact, but colorless, and dry.

OTOH, TAD woofers are a different story. To me they are great. Not as efficient as Altec woofers were/are. But, powered properly, and set up correctly, they sound good, great low end kick, and good low mid response, snares have that wooden snap to them, that is a tonality I treasure, and not many woofers today seem to be able to do. Gives me a LARGE sounding bottom end. And a very fatigue free listening experience. My freinds company is making me amplifiers to drive the, traditonal class AB outputs HUGE power supply, very healthy and clean sounding bass. When I demoed the amp brought to me for evaluation, that bass moved AIR and had definition. True RMS power ratings, and classic circuitry made with high quailty parts just made the TAD woofers sound so effortless. Forget watts per channel, this amp can source tons of current to the woofers. The darwbacks? Price, and weight! These amps are expensive, and they arent light, but, once they are installed in my rack, they stay were they play. I dont have to move my system around, so weight isnt an issue. I auditioned the lab Gruppens, they are good, I audtioned the new style crowns, I dont know, I auditioned this and my ears knew right away, nothing does it like Class AB outputs with lots of output devices, massive power transformers, and huge stored charges for each chammel ( soda can sized capacitors )and a big 20amp power cord for each amp, and each amp on its own dedicated 20amp beaker and receptacle. At $3000 each, for 1000wpc@4ohms, it aint cheap, but, boy, does it do what it should!

[LICORNE]

TAD ? DP-2001

Replacement Beryllium diaphragm for TD-2001

$595.00

TAD ? DP-2002

Replacement Beryllium diaphragm for TD-2002

$865.00

TAD ? DP-4001

Replacement Beryllium diaphragm for TD-4001/TD-4002/TD-400ZZ

$1,175.00


So I guess whith prices like that their volume of production has to be low .A large order would meen a long back log.

http://www.proaudiodesign.com/search...AD&advsearch=1

............................

[scott fitlin]

With TAD, besides the high prices, the other thing they do, or dont do, is they make only so many drivers, and spare parts. They have always been this way, and havent changed.

[scott fitlin]

Oldguy has it correct. JBL cold rolls their Be diaphrgms, TAD sputters the Be.

The vacuum deposting method is considered the best method of manufacturing the diaphragm, because you can make the dome to exacting tolerances. Its also considerably more expensive to produce diaphragms TAD,s way.

Sonically, TAD is the best sounding Be compression driver. JBL 435 Be is OK, but, not as smooth sounding as the TAD 4001 or 4002.

I havent heard the JBL 476Be, so I cannot comment on that driver at this time.

What I can say is that I know the TAD 4001 very well, and I own six TAD 4002,s. Beryllium is the most resolving diaphragm I have ever heard in my life, but, I find thAt aluminum is a sweeter sounding midrange and HF, even though IT IS NOT as extended, or as resolving as Be. In this respect I still prefer Altec 288,s and JBL 2241,s.

I also found that the TAD,s Be diapragms are so resolving that I hear evey flaw, and every imperfection in recordings and it isnt always the most pleasing to listen to. In spite of the fact that Be diaphragms are audibly more extended in the HF response. I do prefer the TAD 4001 over my 4002,s. I think the alnico magnet has something to do with that as I know I love Altec 288-16G,s and JBL 2241,s and Gauss HF 4000,s, all alnico motors. I distinctly DO NOT like JBL 2446,s!

I can also say that to my ears, my TAD 4002,s are the most efficient compression drivers I have ever used. I own 8 JBL 2241,s six Altec 288-16G,s,
and eight Altec 808,s with aluminum phragms and tangerine phase plugs. To my ears the TAD drivers are audibly louder with the same power than my JBL or Altec large format drivers.

I will also concede to Oldguy, the price of TAD is outrageous. The only reason I bought the TAD 4002,s over the 4001,s at the time was because TAD recommended them over the 4001,s and the price was about half what the alnico drivers would have cost me. But, I retospect, I should have spent the additional money for the 4001,s because I like the way they sound better than the neo 4002,s.

Just my 100 opinions!