Acoustically Neutral Panel Fabrics
KnollTextiles uses the ASTM C423 test to evaluate sound absorption and assess which fabrics in our line are appropriate for acoustical panel use. The test reports the Noise Reduction Coefficient (NRC), which is always between “1” and “0”. “1” is said to have perfect absorption and “0” is said to be perfectly reflective. The acoustically neutral range is between -0.25 and 0.25.