NRC DATA

What does NRC Mean?

NRC stands for Noise Reduction Coefficient. It is a representation of the amount of sound energy absorbed after hitting a surface. The NRC of a material can be found by using either the Reverberation Room Method (ASTM C423) or the Impedance Tube Method (ASTM C384). We use the Reverberation Room Method.

1) Approximately 72 square feet of material is rested on the floor of a reverberation chamber. This chamber usually has all hard concrete surfaces.
2) The change in absorption from the empty room to the room with the material is measured.
3) The changes in sound are measured for octave bands ranging from 125Hz to 4000Hz, recording the differences in Sabin absorption coefficients. The overall NRC rating is the calculated average of frequencies 250Hz, 500Hz, 1000Hz and 2000Hz.

NRC (Noise Reduction Coefficient) is an arithmetic value average of sound absorption coefficients at frequencies of 250, 500, 1000 and 2000 Hz indicating a material’s ability to absorb sound.
An NRC of 0 indicates perfect reflection; an NRC of 1 indicates perfect absorption.

The following is a representation of our NRC Data for our products.

Wedge Foam:

Frequency 125 Hz 250 Hz 500 Hz 1000 Hz 2000 Hz 4000 Hz Overall NRC
2″ Wedge Foam .20 .29 .66 .80 .89 1.02 .65
4″ Wedge Foam .39 .61 .91 .79 .95 1.03 .80

 

Pyramid Foam:

Frequency 125 Hz 250 Hz 500 Hz 1000 Hz 2000 Hz 4000 Hz Overall NRC
2″ Wedge Foam .19 .22 .45 .55 .60 .76 .45
4″ Wedge Foam .28 .39 .74 .69 .75 .96 .65

 

Corner LENRD Bass Absorbers:

Frequency 125 Hz 250 Hz 500 Hz 1000 Hz 2000 Hz 4000 Hz Overall NRC
2″ Wedge Foam 1.18 1.27 1.26 .76 1.19 1.16 1.20
4″ Wedge Foam .39 .61 .91 .79 .95 1.03 1.07