Amazon.com: Polymat 10X3.75BLK 10 FEET x 3.75 FEET 10'X3.75' Black Non Woven Felt Fabric Roll 3.33 Yards Compatible with SubWoofer Speaker Box Enclosure, Trunk Liner, Crafts, Multipurpose Mat, Latex Backed Felt :
Amazon.com: Chimailong Speaker Box Carpet Fabric Black: Car Trunk Truck Auto Automotive Liner Speakers Subwoofer Interior Cover Roll Carpeting for Sub Box Polyester Fiber Material 47 X 65 in 21.25 Sqft(Folded) : Electronics
Amazon.com: Polymat 3 FEET * 4 FEET 3'X4' Black Non Woven Felt Fabric Roll for SubWoofer Speaker Box Enclosure Carpet and Trunk, Crafts, Multipurpose Liner, Latex Backed Felt Carpet : Electronics