Speaker foam repair on 15" woofers

I vote for shimming, it really can't hurt, and as long as you don't get dirt into the open gap, yhou should be fine.

I did 6 Advent woofers. The first kit included shims to keep the voice coil centered and had new dustcaps. I did what they said and it works fine. The later kits did not include shims and even though I had them, I did not use shims or replace the dustcaps. Those drivers also work fine.

It isn't difficult or even tedious but you do have to wait for the glues to cure.

I don't vote for shims as it requires careful removal of the dustcap to NOT damage the voice coil leads. Never disassemble more than necessary.

G²

If you go the shimming route. I mark across the dome to cone join as a reference , then cut a neat ring with a narrow tip scalpel. Shims 3x 2mm wide strips of credit card. Reglue the cone with thin hotmelt string and felt-tip/painted black glue line, easier if you ever have to remove again. Unless the cones are on view, no cloth cover, then a more cosmetic glue line required

Use the shims. Leave them in until the glue dries. If you are patient and steady you will do fine. Check YouTube for vids.

As a curiosity, would applying a small voltage across the voice coil keep the cone centered without causing other problems? (small--1, 2, maybe 3 volts)

Mikek

The dust cap is usually ready to fall off by the time the foam dissolves. Otherwise dampen the joint slightly with plain water, wait a few, and lift it off with a hobby knife. If you are worried about debris, use gravity and/or a well placed rag to protect the gap.

I have made shims from plastic water bottles, theatrical gels and the old stand-by "collar stiffeners" for dress shirts. Use at lest 3 and split the gap distance all the way around. Symmetry and full range of unimpeded motion are the goals. Patience is THE virtue.

I was originally thinking a DC voltage, and then had a second thought, How about a 20khz low voltage signal, wouldn't hear it, but it may keep things centered, or even force the fresh glue joint to move and release any tension you/it may have caused installing the foam ring.

Mikek

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Just like it's not a good idea to use your car when the tire pops off the rim.

Thanks for the responses! It will be a week or two before I get to fixing these speakers; I'll post back with results.

Matt Roberds