does a small hole in the foam hurt anything?

[helotaxi 5,000+ posts]

Perfect- just let the silicone fully dry before placing the sub in an enclosure. Although not likely, some glues and foams can be eaten by the silicone outgas.

The thing that you're usually worried about silicone eating is the foam surround...you know the thing you're trying to repair with silicone...

 

[Ninteens 10+ year member]

I once punched a hole in the cone of an old MTX blue thunder. I real big one with a cordless drill.

I used epoxy to seal it, that worked just fine.

But of course thats not the surround. Silicon will work find for that.