Finished replacing the surrounds on my four Allison:One woofers

[Guest rjcrum]

Hi,

This is a duplicate of a message I sent out on the Allison speaker mailing list, but I wanted to include a picture and the mailing list won't let it through. Apologies to those of you who have already seen this...but as I said, I wanted to post the picture, too.

Cheers,

Bob

================Original posting on the mailing list============

Hi, all,

Just wanted to let you know that I finished re-foaming (is that a word?) all four of my Allison:One woofers over the weekend. I got two reinstalled on Sunday, and will reinstall the other two tonight.

The job was, as most people pointed out, easy. I used the Speakerworks Northwest (Oregon) kits, which came in a plain brown bag. Four surrounds, two bottles of glue, two brushes and instructions. Using those instructions, coupled with comments from Tom and Howard here, I had a pretty good idea of what to do.

Only one of the 16 "Tee-nuts" gave me a problem when removing the woofers, and I glued it back into place before screwing the woofer back in. I had to mark the correct wire colors on the woofer connections before I removed them, as there were no markings to denote that. I found out that all four of my woofers were made on August 30, 1976!

Removing the old foam surround was easy, but messy. It appears that the surround was glued to the metal basket using a silicone adhesive; I had to do some major scraping with a utility knife and chisel to get it all off. Peeling the remaining foam off of the speaker cone was also easy, though the butyl rubber (I assume that's what it is) coating left little gobs of goo here and there at the edge where I was removing the old surround. I fiinally picked off all the little rubber globs.

I cleaned everything with rubbing alcohol and let it dry before proceeding. The white glue worked well. I brushed glue on the cone and the inside of the surround and let it dry for about 5 minutes, then pressed the two together. It was actually quite easy to make sure the cone was centered in the surround. I then came back to it and pressed the surround and cone together every 5 minutes for 15 minutes....3 more times. I then let it sit for a couple of hours before proceeding. I did use the wadded-up-paper-towel trick to raise the cone a bit to make it easier to glue the surrounds to the cone.

I then put glue all around the metal basket and gently pressed the surround onto it to coat both surfaces. Again, a 5 minute wait, and then I pressed the surround to the metal basket. It didn't really stick well, as the surround is slightly lower than the basket edge, and consequently it tended to 'curl' up at the outer edge of the surround. I tried the press-it-every-5-minutes trick and that didn't really work well. Obviously, the white glue wasn't setting up as fast on metal. (By the way, it is true...the cone "wants" to be centered in the voice coil; I had no problems centering, and didn't even attempt (or see the need) to cut the dust cap and use shims.)

I tried using some bolts, per the Speakerworks instructions, to hold down the surround on the basket, but that too met with failure. Meanwhile, I'm now worried that after 15 or 20 minutes, the glue will set and not adhere well on the basket/surround interface.

Then, I had an idea. Clothespins as clamps! I quickly found some spring loaded clothespins, and cut pieces of popsicle stick about 1" to 1 1/4" long, and then carefully placed the popsicle stick onto the surface of the surround, and then used the clothespin as a clamp, one face on the bottom of the metal basket, one face on the top of the popsicle stick. I used two clothespins per popsicle stick, for a total of about 32 stick segments and 64 clothespins. I had to be careful that the glue oozing out into the space at the edge of the surround wasn't getting on the stick so as to bond it, too!

I left this over night, and removed the clothespins the next day. It was perfect! So...that's what I did with the other three woofers, with great success.

I think the first woofer took me about 2 hours total, not including the drying time of the glue in both glueing steps. I think that was down to about 1 1/2 hours for the last woofer.

Thanks for the encouragement; it was worth it, and only cost $34!

I noticed, however, that the new surrounds are *much* stiffer than the old ones. Of course, they were deteriorated, but I have to wonder if the new original surrounds were as stiff as the new ones. Also, will that change? Do the surrounds "break in" and become more pliable? Is there an affect on the sound?

Cheers,

Bob

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