How does Plexiglas sound as compared to wood?
If the wood does not flex, and the glass does not flex, then you will not notice a sound difference. The size of the enclosure and the tuning frequency determine the sound. If the box is 3/4″ thick, or 1″ thick or 3″ thick, if they are all 1 cubic foot using the same sub they will sound the same, wood or glass. Glass seals better than wood, it is airtight.