Should I Order 2-inch or 4-inch Acoustic Panels?
Should I order 2 inch or 4 inch acoustic panels?
2 inch panels carry a published NRC of 1.0, the highest rating on our line, and handle general echo, reflections and speech clarity. 4 inch panels reach further into the low end for bass control, but don't carry a single published NRC number, since NRC measures a speech-range band and isn't the right yardstick for bass performance.
NRC (Noise Reduction Coefficient) is an average absorption rating across a mid-range speech band. It's a good single number for comparing general-purpose panels, which is why the 2 inch panel's NRC 1.0 is the headline spec. It doesn't capture deep low-frequency performance, which is why 4 inch panels, built for broadband and low-frequency absorption, are described in those terms instead of a single NRC figure.
Most rooms end up using both: 2 inch panels on the general wall and ceiling surfaces, and corner bass traps in the corners where the low end builds up.
What NRC does the 2 inch panel carry?
NRC 1.0 (per ASTM C423), the full broadband rating.
What NRC does the 4 inch panel carry?
None is published. 4 inch panels are built for broadband and low-frequency absorption; NRC is a speech-range number and isn't the right measurement for bass performance.
Can I mix 2 inch and 4 inch panels in the same room?
Yes, this is common: 2 inch panels on the general wall and ceiling surfaces, corner bass traps in the corners.
Which should I start with if I can only buy one?
2 inch, for general-purpose rooms. Add corner bass traps later if the low end still feels boomy.
See 2 inch panels or 4 inch bass trap panels.
See the full comparison: 1 inch vs 2 inch vs 4 inch acoustic panels.
