Owens Corning 703 4" is a popular material for acoustic absorption, especially with low frequencies. A Case contains 3 pieces of the 24" x 48" x 4" product. For smaller quantities, buy Owens Corning 703 4" Single Pieces here.
Typically, the insulation boards are covered with fabric and mounted on the walls in a studio, control room, or listening room. The 4" Owens Corning are also strong and rigid .
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For more detailed information, see Selecting the Right Acoustic Material for a comparison of these materials.