1 Inch vs 2 Inch vs 4 Inch Acoustic Panels: Which Thickness Do You Need?
For most rooms, choose 2 inch acoustic panels. Our 2 inch fabric-wrapped fiberglass panels are rated NRC 1.0 per ASTM C423 and control echo, reverb and speech clarity across the range where most room problems live. Choose 1 inch panels (NRC 0.80, Intertek tested per ASTM C423) for speech-focused rooms on a tighter budget. Add 4 inch panels or corner bass traps when the low end booms, because NRC does not measure bass and depth is what buys bass control.
Want the answer for your room? The room coverage calculator suggests thickness, count and placement, or send photos and dimensions through the Free Room Analysis.
Thickness at a glance
| 1 inch panels | 2 inch panels | 4 inch panels | Corner bass traps | |
|---|---|---|---|---|
| Rating | NRC 0.80 (Intertek tested, ASTM C423) | NRC 1.0 (ASTM C423) | No single NRC published | No single NRC published |
| Strongest at | Mid and high frequencies: voices, reflections, ambient noise | Broadband echo and reverb, including some low-mid | Broadband, with more low-frequency reach | Low frequencies where bass piles up |
| Where it goes | Walls in offices, classrooms and podcast rooms | Walls and ceilings in most rooms | Flat walls and ceilings, not corners | Room corners, stacked floor to ceiling |
| Sizes | 24 x 24, 24 x 36, 24 x 48 in | 24 x 24, 24 x 36, 24 x 48 in; large format up to 48 x 96 in | 24 x 24, 24 x 36, 24 x 48 in; large format up to 48 x 96 in | 24 x 24 and 24 x 48 in faces, 13 in deep |
| Price range (Sept 2026) | $39.99 to $109.99 | $39.99 to $119.99; large $159.99 to $449.99 | $69.99 to $159.99; large $274.99 to $649.99 | $199.99 to $419.99 per pair |
Current prices are on each product page: 1 inch, 2 inch, large 2 inch, 4 inch, large 4 inch and corner bass traps.
What NRC measures, and what it misses
NRC (Noise Reduction Coefficient) is a single-number rating per ASTM C423: the average absorption across four test bands, 250, 500, 1000 and 2000 Hz, rounded to the nearest 0.05. It is a good way to compare panels for echo and speech. It does not include performance below 250 Hz, so bass control takes 4 inch panels or dedicated bass traps. That is why our 4 inch panels and corner traps are described by what they do, not by an NRC number. Read more in NRC 1.0 explained.
When 1 inch panels are enough
1 inch panels handle mid and high frequencies, the range of voices, reflections and ambient noise. In voice-focused rooms such as offices, classrooms and podcast rooms they do the job at a lower cost. They will not treat low-mid buildup or bass, so music rooms and home theaters are better served by 2 inch panels.
Why 2 inch panels are the default
Our 2 inch panels use a 6 lb density, American-made rigid fiberglass core and are rated NRC 1.0 per ASTM C423. They absorb a broader range than 1 inch panels, including some low-mid frequencies, and work on walls and ceilings in studios, home theaters, offices, churches and restaurants. For big walls and rooms over 300 square feet, large-format 2 inch panels up to 48 x 96 inches cover more area with fewer panels. The room size guide shows the math.
When you need 4 inch panels or bass traps
Step up when bass is boomy, muddy or uneven: music mixing, a home theater with a subwoofer, or a small room where the low end builds up.
- Corners get corner bass traps. Bass pressure piles up where walls meet. Our Corner Bass Traps are built 13 inches deep, stack floor to ceiling and are sold in pairs. Most rooms benefit from treating at least the two front corners.
- Flat walls and ceilings get 4 inch panels. They mount flat like a 2 inch panel and reach further into the low end. They are not made to wedge into corners.
Fabric choices at every thickness
Our 1 inch, 2 inch and 4 inch panels are offered in Burch Fabrics Prime Time, Guilford of Maine lines, microsuede and burlap. Burch rates Prime Time Class A per ASTM E-84. Microsuede and burlap are not fire rated. Burch Fabrics Prime Time is the Made in the USA equivalent of Guilford of Maine (a Canadian company) Anchorage and FR701. Fabric color has a negligible effect on absorption. For rated commercial rooms, see fire-rated acoustic fabric for commercial use.
Plan your room
Every panel is custom built in the USA. Send your room through the Free Room Analysis and we will recommend the thickness, count and placement. Questions: call 888-923-5777. Custom and made-to-order panels are not returnable once payment is received; see the Refund Policy.
Frequently asked questions
Should I buy 1 inch or 2 inch acoustic panels?
For most rooms, 2 inch. Our 2 inch panels are rated NRC 1.0 per ASTM C423 and absorb a broader range, including some low-mid frequencies. 1 inch panels are rated NRC 0.80 (Intertek tested per ASTM C423) and suit speech-focused rooms like offices, classrooms and podcast rooms at a lower cost.
Do 4 inch acoustic panels have a higher NRC than 2 inch panels?
No single NRC is published for our 4 inch panels. NRC averages four speech-range bands from 250 to 2000 Hz and is not the right measure of bass. Our 2 inch panels carry NRC 1.0, and 4 inch panels are built for broadband absorption with more low-frequency reach.
Are 4 inch acoustic panels bass traps?
Our 4 inch Bass Trap Panels are flat panels. They add low-frequency reach on walls and ceilings. For corners, where bass builds up most, use our Corner Bass Traps, built 13 inches deep and priced by the pair.
Can I mix panel thicknesses in one room?
Yes, and most rooms do: 2 inch panels on the walls and ceiling, corner bass traps in the corners. If you can only buy one kind now, start with 2 inch and add bass traps later if the low end still booms.
What thickness is best for a recording studio or home theater?
Most studios and home theaters use a mix: panels at the first reflection points and corner bass traps in the corners. Use 2 inch panels for general echo and step up to 4 inch panels on the walls when the bass is boomy or uneven.
Do thicker acoustic panels soundproof a room?
No. Acoustic panels of any thickness absorb sound inside a room. They do not block sound from passing between rooms. NRC measures absorption, while STC measures how much sound a wall assembly blocks.
