I have a pair of two year old Pioneer BS22 bookshelf speakers. Today I found that ants / insects have dug a few holes in the driver cone and tweeter dome of one of the speaker. The other speaker is intact. When I compered the SQ of both in isolation, I found that the speaker with holes gives less bass / thump than the other one. I want to fix the holes in a DIY way. After searching for solution in other threads in this forum, I found that I could use either fevicol fabric glue or silicon sealant to cover the holes. I want advise on what is the best way to fix the holes.