What Fabric Should You Use for Acoustic Panels?
Updated
Use a breathable polyester acoustic fabric rated ASTM E84 Class A, such as Guilford of Maine FR701, which its maker rates 95% acoustically transparent (Duvaltex FR701 spec (opens in a new tab)). So that's what fabric to use for acoustic panels, in short: it has to let air through easily and carry a published fire rating.
Check both before you buy a bolt:
- Blow test. Hold a single layer against your mouth, put your palm behind it and blow. Feel air on your palm? Then sound will get through to the core. If your cheeks puff out instead, the fabric's going to bounce the highs back.
- Fire rating. Class A means a flame spread index of 0 to 25 and smoke developed of 450 or less. Those are the classes the building code uses for wall and ceiling finishes (IBC 803.1.2, via WoodWorks (opens in a new tab)).
Skip vinyl, leather, coated and blackout fabric. A sealed face hurts the treble most: Owens Corning's foil-kraft facing on 2 in. 703 board drops absorption at 2,000 Hz from 1.02 to 0.51 and NRC from 1.00 to 0.75 (703 data sheet (opens in a new tab)). Upholstery polyester can work, as long as it passes the blow test and the seller can show you an E84 rating.
Example: Allow the panel's thickness on every edge, plus 1.5 in. to fold onto the back. A 24 x 48 x 2 in. panel needs a 31 x 55 in. piece, so four panels take 4 × 31 = 124 in. of a 66 in. wide bolt, about 3.5 yd.
The core matters as much as the cover. What acoustic panels are made of goes over the options, and fiberglass and mineral wool soundproof panels compares the common boards. Placement is covered in the soundproof panels guide, and there are more answers in the soundproof panels FAQ.