Understanding NRC: How to Choose an Acoustic Panel

Si you're shopping for acoustic panels, you've probably come across the acronym NRC on a product sheet—often a number between 0 and 1, with little explanation. Yet, it's the only truly useful data for comparing two panels, provided you know exactly what it measures (and especially, what it doesn't measure).

What is NRC (Noise Reduction Coefficient)?

NRC (Noise Reduction Coefficient) is a single rating, from 0 to 1, that indicates the proportion of sound a surface absorbs rather than reflecting back into the room. An NRC of 0 means the surface reflects virtually all sound (like a windowpane or a bare drywall); an NRC of 1 would mean total absorption.

Specifically, NRC is calculated by testing a material in a laboratory at four precise frequencies—250, 500, 1000, and 2000 Hz—and then averaging the four results. This is a standardized method (ASTM C423), which theoretically allows for comparing NRC ratings from two different manufacturers. We say "theoretically" because one detail changes the entire result: how the panel is mounted.

Mounting changes the rating—beware of a single number

The same panel can show two very different NRCs depending on whether it's glued flat against the wall or installed with an air gap behind it. The air gap allows low frequencies to circulate and be absorbed more, which increases the rating.

This is the case with our own panels: mounted flat against the wall, they show an NRC of 0.55. With a one-inch air gap behind the panel, this figure climbs to 0.65. A product sheet that announces a single high NRC without specifying the mounting hides part of the information—always ask about the tested mounting before comparing two products.

What NRC rating is good for your space?

There is no universal "good" NRC—it all depends on what you're trying to correct:

• 0.0 to 0.2 — hard, reflective surfaces (glass, bare drywall, ceramic). No acoustic treatment.
• 0.3 to 0.5 — light acoustic treatment, useful for softening a room without aiming for precise echo control.
• 0.55 to 0.75 — the range where most effective acoustic panels for echo and speech reverberation are found (open-plan offices, restaurants, meeting rooms).
• 0.8 and above — very high absorption assemblies, generally reserved for specialized environments (recording studios, performance halls).

For a residential room or a standard office, a rating between 0.5 and 0.65—like that of our panels with an air gap—covers the vast majority of needs.

Acoustic panel = sound treatment within a room, not a wall between two rooms

This is the most important point, and the one that causes the most confusion: NRC measures absorption, meaning the ability of a surface to reduce echo and reverberation within the same room. It has nothing to do with preventing sound from passing from one room to another (for example, hearing the apartment neighbor, or a conversation through a wall).

This second problem is measured with a completely different rating, the STC (Sound Transmission Class), and it's solved with different products—insulation in walls, solid doors, acoustic decoupling of the structure. An acoustic panel, even with an excellent NRC, will not block sound between two rooms: it's simply not what it's designed to do.

Specifically, our panels are designed for the interior of a space: less echo, a dining room where you can hear yourself talk, an open-plan office that's less tiring at the end of the day. They are also printed directly on the surface, so each panel does the double duty of acoustic treatment and wall art—a practical choice when you don't want to add another gray panel to the wall in addition to the decoration.

If your real need is to prevent sound from passing through a wall or floor, an printed acoustic panel is not the right solution—and we prefer to tell you clearly rather than sell you the wrong product for the wrong problem.

How to choose according to your room and style

Once NRC is understood, the choice comes down to two questions: what absorption surface do you need, and what style fits your room.

• For a warm and textured look—living room, family room, atmospheric restaurant—the Raw Materials collection, with its wood slat panels, integrates as a finishing element rather than a visible addition.
• To transform acoustic treatment into a work of art in its own right—home office, meeting room, corridor—the Artistic Canvas collection allows you to choose a pattern or image that becomes the focal point of the room, like the Romeo panel.

In both cases, the NRC displayed on the product sheet remains the data to compare—and now you know exactly what it means.