Don’t laugh, but I had a lot of extra polyethylene foam (the kind used inside of life preservers) and a lot of extra carpet squares, so I insulated the cabin for sound. I cut pieces of the carpet squares a bit wide and bowed them up to secure them firmly. I also added a few dots of adhesive to ensure they do not fall or move. The carpet squares are very dense rubber and synthetic fabric and deaden the sound in the cabin considerably.