Butyl Surround Kits?

pinkmouse

diyAudio Moderator Emeritus
2002-04-03 7:15 pm
Rotherham, England
Try pro audio suppliers, ( if you haven't already), a lot of pro PA drivers now have rubber surrounds, and mid range PA drivers range from 4" to 12" in diameter, so you may find something there...

Be aware though, changing the surround will affect the parameters of the driver, but you probably know this already!!! :)
 

kelticwizard

diyAudio Moderator Emeritus
2001-09-18 2:33 am
Connecticut, The Nutmeg State
I wonder how much the surround really changes the Thiele-Small parameters.

For a repair job on some cheap speakers, I used Saran wrap, which is made of vinyl or a vinyl compound. It looked like hell, but it worked okay.

If you take the surround off the speaker, it droops limply in your hand, as does the brand new foam replacements. Yes, I know the circular shape, when installed, adds stiffness.

But it seems to me that 99% of the stiffness in the suspension comes from the spider. If you cut the spider out of an old speaker, it certainly is not limp-it's springy.

I think the surround is just stiff enough to hold the cone in the center, and is so soft compared to the spider that the surround material matters little. I think it is the spider that is the key to the Thiele-Small parameters.

I have never measured the parameters to make sure, but that is my educated guess.

By the way, if you ever do decide to "do-it-yourself" without a kit on some cheap speakers, use Saran or vinyl wrap only. Never even try to use the normal plastic food wrap. Why? Nothing sticks to it. There is no glue that sticks to that polyethylene wrap. But most any plastic glue will stick to Saran or vinyl wrap. As long as the substance has "vinyl" in the name somewhere-like polyvinyl chloride, (PVC), the plastic or vinyl glue will stick to it.
 
I am looking for a stiffer more solid surround than the foam as I want to add a flat surface to an old pair of 8"ers rebuilt as subs and know the local speaker rebuilder has only foam. I am determined to build a PP isobaric sub and know that foam will not survive the $%%^&&&^% cats very long. They are not mean $%##%$&^^ cats, but just do cat things. I leave her cats alone and she leaves my hifi alone.
 

roddyama

diyAudio Moderator Emeritus
2002-01-19 9:25 am
Michigan
Hi Thatch,

About a year ago, I sold a pair of JBL 124A's to a guy that lives in Michigan. They were in super shape except for the aging foam surrounds. Early this summer, I seen he had those same speakers (by sn) for sale with new "rubber" surrounds. If I can find his email, I contact him and ask where he had it done. I would be interested as well.

Rodd Yamas***a
 
I agree about the spiders being more imprtant to the effiancy of a driver than the surround and know that there even different stiffnesses available in the foam, my greatest concern is not stiffness of the surround or longevity of the surround just that butyl is much less likely to get cut by a cat's claw. I just happen to have a pair of good canidate for subwoofer 8"ers that need to be rebuilt and doubt the repair guy could or would order a single pair of butyls for this.
 

kelticwizard

diyAudio Moderator Emeritus
2001-09-18 2:33 am
Connecticut, The Nutmeg State
Somebody sells butyl kits somewhere. Leather ones too. This is from an Australian site:
http://www.turneraudio.com.au/Repairs.htm

Look near bottom of page.

Jaycar is in Australia. Maybe those kits they sell are butyl and not foam. Worth a call, probably. As stated previously, remember the Australian dollar is 60 cents American.
 

kelticwizard

diyAudio Moderator Emeritus
2001-09-18 2:33 am
Connecticut, The Nutmeg State