How many acoustic panels do I need?

Two rules of thumb

Panel makers publish coverage guidance, but they measure it differently:

• Primacoustic: 15–25% of the wall surface area as a starting point; 25% or more for critical listening and theaters.
• Acoustimac: 25–30% of all hard surfaces, which includes the ceiling and bare floor.

Neither is a standard, and they shouldn’t be compared directly. Both say the same thing: a meaningful fraction of the room, not one or two panels.

Worked out for common rooms

Using Primacoustic’s 15–25% of wall area, with an 8-ft ceiling and 2 × 4 ft panels (8 sq ft each). Window and door area is included, so real counts are a little lower.

Room	Wall area	15%	25%	2 × 4 ft panels
12 × 11 ft	368 sq ft	55 sq ft	92 sq ft	7–12
15 × 13 ft	448 sq ft	67 sq ft	112 sq ft	9–14
16 × 14 ft	480 sq ft	72 sq ft	120 sq ft	9–15
20 × 16 ft	576 sq ft	86 sq ft	144 sq ft	11–18

These are upper-end starting figures for bare rooms. A living room with a large rug, heavy curtains, an upholstered sofa and bookshelves already has much of the absorption it needs, and often sounds right with half as many panels.

Add them in order, and listen

1. Four panels at the side-wall first-reflection points, for the front left and right speakers. This is where panels make the clearest difference.
2. A ceiling cloud between the front speakers and the seats.
3. Two to four panels on the wall behind the seats, especially if the sofa sits close to it.
4. Corner bass traps, if bass booms. See bass traps.
5. Stop when speech is clear and the room no longer rings when you clap. CEDIA/CTA RP22’s decay target for a typical living room works out to about 0.25 seconds; well below that, extra panels make the room sound dead.

Thickness changes the count

Thick panels do more per square foot. GIK recommends 2 inches as a minimum for speech and 4 inches or more for music and cinema. ROCKWOOL’s lab test of its ROCKBOARD 60 shows why: a 2-inch board absorbed about a quarter of the sound striking it at 125 Hz, a 4-inch board nearly all of it. Ten thin panels can leave a room both dull and boomy; six thick ones usually sound better.

Let Room Studio count for youIts acoustics guide adds panels one at a time and shows how much each improves the room. Open Room Studio →