Hello. I've had a home theater in a box for quite some time. I recently decided to rebuild my speaker enclosures to give them a more solid look. When I disassembled the old ones, there was a strip of insulation glued to the inside walls of each speaker. I am curious as to the purpose of this insulation and what would be considered a good replacement, or if it is even necessary at all. I believe it would be some sort of sound dampener, but it is just a guess. Any help would be greatly appreciated. I am holding off sealing the speakers until this issue is resolved. Thanks for reading everyone.