old surround and whizzer issues

[Geoff H]

It does have a "Yes" look to it. I feel sorry for the younger generation. They missed out on Yes, Supertramp, Steeleye Span (not Steely Dan) and Jethro Tull to mention a few.

AD12100/HP8 could be the one with the Butyl Rubber impregnation.

AD12100/W4 sounds like the main one we were using. Rolled rubber surround. OK up to about 700 Hz.

At the time, we were hooked up to the 3-ways, cause that's what sold well. Then we discovered big 2-ways from California.

Unfortunately, I haven't seen the Philips Speaker Design Handbook for a few years.

I might just have to get close to the edge, down by the river. Nice.

[BudP]

Geoff,

I have a copy of what is called "Building HI FI Speaker Systems". With Phillips as the presenter and M.D. Hull, C, Eng, A.M.I.E.R.E. listed as the author. Is this the book you are referring to? I would be happy to scan what, if any, data you might want and post it for you.

Bud

[Geoff H]

Thanks Bud. That does sound like the book. Not for me though. Zen might want some data from it. We need to identify what the surround is treated with. If it is butyl rubber, Zen could have a problem. Once it goes hard, I think there is little that can be done to restore it without dissolving everything else.

Regards,
Geoff

[Zen Mod]

Originally posted by BudP
Geoff,

I have a copy of what is called "Building HI FI Speaker Systems". With Phillips as the presenter and M.D. Hull, C, Eng, A.M.I.E.R.E. listed as the author. Is this the book you are referring to? I would be happy to scan what, if any, data you might want and post it for you.

Bud

Originally posted by Geoff H
Thanks Bud. That does sound like the book. Not for me though. Zen might want some data from it. We need to identify what the surround is treated with. If it is butyl rubber, Zen could have a problem. Once it goes hard, I think there is little that can be done to restore it without dissolving everything else.

Regards,
Geoff

yes...... (too old for R'n'R........too young to die.......... )

BudP -can you just look is there any info regarding surround type for AD12100/HP8..........even if Cal's post ( http://www.diyaudio.com/forums/showt...46#post1187546 ) about 2-butoxyethanol seems promising , it's wiser to check things twice

[BudP]

Zen,

This particular edition has no reference to the AD12100/HP8. Does refer to AD12200/W and AD12650/W high performance woofers but none of the technical charts throughout the book make any reference to the surrounds or materials they are created from. None of the other catalog data I have goes back past 1992 so no help there either.

Sorry,
Bud

[Geoff H]

Zen, BTW, I got "close to the edge" last night, and trimmed the remains of my domes, no river of tears though! while Yes was playing!
Today, shaping plugs, and taking FRs as I go. Interesting stuff. Top end just keeps getting sweeter and sweeter, and still loads of dynamic range.

[Zen Mod]

Originally posted by Geoff H
Zen, BTW, I got "close to the edge" last night, and trimmed the remains of my domes, no river of tears though! while Yes was playing!
Today, shaping plugs, and taking FRs as I go. Interesting stuff. Top end just keeps getting sweeter and sweeter, and still loads of dynamic range.

[78_towncar_460]

BudP,

You worked at Nestorovic Labs? Any info on that?

I have a pair of Speakerlab speakers and I want to know as much as I can about them. I know he had a hand in the design as I have been told by an ex-employee of Speakerlab.

I tried to email you but I don't have enough posts. I usually just read.

[rjb]

Resurrecting an old thread.

I now have a pair of Ad12100 W with butyl surround and cloth spider. Tests show much higher resonance freq presumably due to stiffer suspension. Both test similarly, but not identical.

The surrounds seem flexible still, so its the spider hardening.

Does anybody have more practical information or results than in this thread?

Incidentally I also have a copy of Hull's book mentioned above

[thoriated]

I found I could considerably loosen the spider on Aurasound NS3 clones by exercising the individual rolls with a blunt plastic rod with a short r/a end section having a diameter about the same as the inside diameter of the spider pleats. With that approach I could loosen the fabric considerably more than even running the cone to the limits of its excursion and much more quickly, also.

By individually flexing all of the pleats around their circumferences, I was able to reduce the Fs of these drivers from as high as 90 plus Hz (~80hz average) to 55-62hz in less than 5 minutes for each driver with no stress or misalignment problems resulting. This is probably because with this technique, only about 10% of the spider was being flexed at any time, and only a modest amount of cone excursion per se (~1/8") occurred during this process.