Sound Absorbing Panels for Gyms The best sound absorbing panels for gyms are high-NRC (0.80+) fabric-wrapped fiberglass or polyester panels, 2-4 inches thick, installed at 6-10 feet height covering 25-60% of wall area. For maximum performance, choose panels specifically engineered for fitness facilities with moisture resistance, impact durability, and Class A fire ratings. The right solution depends on your gym type: CrossFit boxes need 4-inch panels for bass absorption from