The Whole Truth About Beryllium Diaphragms - Page 12

pieter t · 17th June 2009, 04:13 PM

Earl,

You are totally wrong in stating that a Yamaha beryllium dome-clone could be made for a few dollars.
At the time Yamaha built their own equipment to manufacture these domes. Google a bit and you will find a picture of equipment that will not fit in your garage. The beryllium was vaporized and vacuum deposited. A very dangerous procedure because vaporized beryllium is very poisonous (beryllose kills much faster than asbestose, and the technique is forbidden in most western countries).
Up to this day these transducers are state-of-the-art.
It is no coincidence that JM Labs/Focal and now Usher try to pick their grain of beryllium.
In my opinion and experience much innovation in audio is done in Japan in the seventies and eighties, and quality was at a very high level. Not only loudspeakers, also electronics. Think of Sony and Yamaha with their VFet amplifiers; Nakamichi made cassette a listenable medium; Luxman; Accuphase. Each of the major Japanese brands had their flagship models at the time. Many of these did not make it into western markets.
I totally agree with you that audio in general took the wrong direction. Yamaha now is not Yamaha thirty years ago and the same is true for many more brands. Like you I am professionally active in the DIY market so I know what you mean.
Comparing beryllium and non-beryllium drivers attached to horns or waveguides does not tell much about differences in transducers, agree, because much of the sound will be blurred by horn colorations.
Comparing a direct radiating Yamaha midrange dome to some other direct radiating midrange dome or cone tells a lot more but I guess that only NS1000 owners understand what I mean.

Pieter

gedlee · 17th June 2009, 04:28 PM

Pieter

We see things differently I guess.

soongsc · 17th June 2009, 05:29 PM

Quote:

Originally posted by gedlee
Not to steal Steve's response (he can still respond) but the idea is a simple one.

Breakup is bad. Basically once a diaphrgam begins to break up it will start to color the sound - it can no longer be flat and smooth. This is very tru I think, but is most true in the frequency range of say 800 Hz - 8 kHz. Above about 8 kHz it seems to me to be a highly suspect argument.

I would never use a driver in the 800 - 8 k range if it had cone breakup there. Thats what crossovers are for.

The higher the speed of sound in the material the higher the breakup region will begin. But damping is more important than the frequency location. A well damped breakup will be much less audible than a underdamped one, even when a crossover is used. So a material with a high internal damping is best because add on damping lowers the breakup frequencies due to added mass. Paper and some plastics excell here.

If Scanspeak uses a so called pure Beryllium diaphragm in ther driver shown below, I certainly can't see much change in breakup frequency location, let alone damping.
http://www.scan-speak.dk/datasheet/pdf/d3004_664000.pdf

soongsc · 17th June 2009, 05:32 PM

Quote:

Originally posted by DcibeL
From ZaphAudio:

A lot of what has already been stated has been recapped by Zaph, but in addition to that he has a real deal Be tweeter to be tested so we can see some real results! Exiting stuff!

I would be interested in seeing the tests.

soongsc · 17th June 2009, 05:37 PM

Quote:

Originally posted by angeloitacare
Hi Steve

could you explain the correlation of speed of sound property, and sound quality ? Why should Beryllium , in regard of this argument, just because sound propagates faster, sound better ?

I got my stool ready for a long response. But I won't hold my breath while waiting for it.

mowry · 17th June 2009, 07:12 PM

Which one is the real beryllium?

mowry · 17th June 2009, 08:17 PM

Question?

How did Usher Audio win so many awards and get such rave reviews?

DcibeL · 17th June 2009, 08:26 PM

If you seriously think the answer is because the reviewers thought they were made of pure Beryllium, you have got to be kidding!

Steve, do you have any business connection with Brush Wellman?

pieter t · 17th June 2009, 08:31 PM

Earl,

No problem with different viewpoints.
There are many ways to get good quality audio.

I try to upload a picture of Yamaha's vapor-vacuum system to manufacture the beryllium domes.

Pieter

Robh3606 · 17th June 2009, 08:36 PM

"Which one is the real beryllium?"

Good luck telling by eye.

Rob

17th June 2009, 04:28 PM	#112
gedlee diyAudio Member Join Date: Dec 2004 Location: Novi, Michigan	Pieter We see things differently I guess. __________________ Earl Geddes Gedlee Website Read about the highly acclaimed Geddes loudspeakers

17th June 2009, 08:26 PM	#118
DcibeL diyAudio Member Join Date: May 2003 Location: Saskatchewan	If you seriously think the answer is because the reviewers thought they were made of pure Beryllium, you have got to be kidding! Steve, do you have any business connection with Brush Wellman? __________________ The power of Science compels you!

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17th June 2009, 04:13 PM	#111
pieter t diyAudio Member Join Date: Apr 2009	Earl, You are totally wrong in stating that a Yamaha beryllium dome-clone could be made for a few dollars. At the time Yamaha built their own equipment to manufacture these domes. Google a bit and you will find a picture of equipment that will not fit in your garage. The beryllium was vaporized and vacuum deposited. A very dangerous procedure because vaporized beryllium is very poisonous (beryllose kills much faster than asbestose, and the technique is forbidden in most western countries). Up to this day these transducers are state-of-the-art. It is no coincidence that JM Labs/Focal and now Usher try to pick their grain of beryllium. In my opinion and experience much innovation in audio is done in Japan in the seventies and eighties, and quality was at a very high level. Not only loudspeakers, also electronics. Think of Sony and Yamaha with their VFet amplifiers; Nakamichi made cassette a listenable medium; Luxman; Accuphase. Each of the major Japanese brands had their flagship models at the time. Many of these did not make it into western markets. I totally agree with you that audio in general took the wrong direction. Yamaha now is not Yamaha thirty years ago and the same is true for many more brands. Like you I am professionally active in the DIY market so I know what you mean. Comparing beryllium and non-beryllium drivers attached to horns or waveguides does not tell much about differences in transducers, agree, because much of the sound will be blurred by horn colorations. Comparing a direct radiating Yamaha midrange dome to some other direct radiating midrange dome or cone tells a lot more but I guess that only NS1000 owners understand what I mean. Pieter

17th June 2009, 08:17 PM	#117
mowry diyAudio Member Join Date: Dec 2008	Question? How did Usher Audio win so many awards and get such rave reviews?

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