What does NRC stand for?
NRC stands for Noise Reduction Coefficient. NRC is the average of absorption readings obtained at four frequencies: 250, 500, 1000 and 2000 Hertz (Hz). For example, a reading of .85 at 250 Hz. means that 85% of the sound striking the Acousta-Wal surface at this frequency (250 Hz.) is absorbed and, therefore, not reflected back into the room as unwanted noise. It is customary and useful to take readings at 125 and 4000 Hz. even though they are not used to calculate NRC. Although NRC is a convenient measure of a product’s acoustical performance, it is something of a “shotgun” approach and should not be depended upon when choosing sound absorbing materials for a specific application.
