On Tuesday, November 13, 2018 at 11:06:15 AM UTC-8, John-Del wrote:
This is a favor for a friend of a friend. I've never done a refoam before but I realize it's not rocket science but there's probably a learning curve. I won't have the option of do a trial run.

These drivers come out of a pair of Infinity Crescendos, and the plastic dust caps seem well bonded to the cone. I'd much prefer to shim the cone before bonding the foams, but I don't know if the dust caps can be removed somehow from the cones without damaging them.

Any advice appreciated.

I've done 6 refoams on Advent woofers and 2 on 6" JBL drivers. The first Advent kit came with shims and new dust caps. I followed the instructions and they worked fine. The next sets came without shims and I did not use any and everything is fine. I know the gap in the Advent drivers is quite large though I don't know if it's different in other brands. I have no idea what the gap is in the JBL but had no problem. As long as the spider hasn't shifted I don't think you'll have problems.

G²