How Thick Are Acoustic Wall Panels?
Updated
Most acoustic wall panels are 1 to 2 inches thick, decorative felt panels are about 1/2 inch, and panels meant for bass are 4 inches or more. Auralex sells its Studiofoam Wedge in 1, 2, 3 and 4 in. (product page (opens in a new tab)), and Acoufelt's PET felt comes in 12 mm, about 1/2 in., rated NRC 0.45 (spec sheet (opens in a new tab)).
Acoustic panel thickness decides how low a panel can absorb. Owens Corning 703, a common fiberglass core, shows the pattern nicely (data sheet (opens in a new tab)):
| Thickness | NRC | Absorbed at 125 Hz |
|---|---|---|
| 1 in. | 0.70 | 5% |
| 2 in. | 1.00 | 15% |
| 4 in. | 1.15 | 56% |
Notice the NRC barely moves past 2 in. That's because it only averages 250 to 2,000 Hz (Acoustical Society of America (opens in a new tab)). The extra inches pay off down in the bass, which NRC leaves out. You'll find the cores compared in fiberglass and mineral wool soundproof panels.
Go by the lowest sound you need to tame: 1/2 to 1 in. for voices and harsh highs, 2 in. for general echo in offices and living rooms, 4 in. for home theaters, studios and corners where bass piles up. The soundproof panels guide shows where each one goes in a room, and there are more answers in the soundproof panels FAQ. Thicker panels won't block noise from next door, and they add only a little heat insulation; do acoustic panels help with insulation runs those numbers.