fer sure.
Hi Zen, just saw your request in the other thread.
The bitumen paint I use says to thin it use 5% mineral turpentine, so I figured that would act as a solvent. It did on the little Pannasonics, but not on some old 10" Westwells, which also have matt black paint on/in the surrounds (FS @ 120Hz). So it may help.
That fibrous stuff on your surrounds would not be helping. Acetone may help remove it, but it may also dissolve the cone/surround and surround/frame adhesive.
On the mineral turps. It does creep, and will end up on the radiating surface, which doesn't seem to hurt, but I like the bitumen to flow on the edge of the cone, to reduce edge resonances.
Corrugated cloth surrounds are available in Australia, they might be available in your neck of the woods.
Good luck with them, I think they're worth preserving.
Geoff.
Edit: He should duck'n'weave, BudP that is. Foam, tut tut.
The bitumen paint I use says to thin it use 5% mineral turpentine, so I figured that would act as a solvent. It did on the little Pannasonics, but not on some old 10" Westwells, which also have matt black paint on/in the surrounds (FS @ 120Hz). So it may help.
That fibrous stuff on your surrounds would not be helping. Acetone may help remove it, but it may also dissolve the cone/surround and surround/frame adhesive.
On the mineral turps. It does creep, and will end up on the radiating surface, which doesn't seem to hurt, but I like the bitumen to flow on the edge of the cone, to reduce edge resonances.
Corrugated cloth surrounds are available in Australia, they might be available in your neck of the woods.
Good luck with them, I think they're worth preserving.
Geoff.
Edit: He should duck'n'weave, BudP that is. Foam, tut tut.
Zen, a couple of questions.
Are these speakers the ones you posted in the B200 thread?
Now for your thinking cap. Back in 75-76 a good friend of mine was building (commercially) a range of systems, mostly with Philips drivers.
The larger ones were fitted with 12" bass drivers with a butyl rubber surround, rated at 40 watts, and IIRC correctly 27 Hz. I am certain that they had ceramic magnets.
There was an alternative. A bass driver with a butyl rubber impregnated cloth surround. I am sure they were Philips, but they could have been SEAS or Scanspeak.
The weave (similar to that on spiders) on those stiff surrounds looks just like b-r impreg. jobs.
Also, do the spiders feel stiff?
Best check with an industrial chemist type.
Geoff
Edit: What happened to the "eye"?
Are these speakers the ones you posted in the B200 thread?
Now for your thinking cap. Back in 75-76 a good friend of mine was building (commercially) a range of systems, mostly with Philips drivers.
The larger ones were fitted with 12" bass drivers with a butyl rubber surround, rated at 40 watts, and IIRC correctly 27 Hz. I am certain that they had ceramic magnets.
There was an alternative. A bass driver with a butyl rubber impregnated cloth surround. I am sure they were Philips, but they could have been SEAS or Scanspeak.
The weave (similar to that on spiders) on those stiff surrounds looks just like b-r impreg. jobs.
Also, do the spiders feel stiff?
Best check with an industrial chemist type.
Geoff
Edit: What happened to the "eye"?
Geoff H said:
beauties in B200 thread are AD1256/M4 (AlNiCo);condition as written there ;
these ones are AD12100/HP8 , ceramic magnet ; as seems to me surround is main reason for stiffness ,not spider.
and surround is clearly made from cloth .
btw-I have somewhere here just one AD12100/W4 - that's variant with rubber surround,black dustcap and Fs around 19Hz.......
...you lost me with :
?
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.
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.
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
Regards,
Geoff
BudP said:
Geoff H said:
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/showthread.php?postid=1187546#post1187546 ) about 2-butoxyethanol seems promising , it's wiser to check things twice
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
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
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.
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.
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
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
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.
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.
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