48 Pack of (12x12x1) Inch Acoustical Pyramid Foam for Soundproofing Studio/Home Theater For basic soundproofing, 1 inch pyramid foam provides moderate sound control on walls or ceilings, especially ones not parallel to the floor. This product is best for when absolute sound deadening is not required, but moderate deadening is desired. 1 inch pyramid foam is most effective on mid-to-high frequency ranges. The 48 packs of wedge foam are available in the following colors: Charcoal, Red, Orange, Rosy Beige, Brown, Burgundy, Blue, Purple, Plum, Teal, Kelly Green, and Forest Green. This foam is truly colorized and not surface-painted, ensuring uniformity, and is designed to resist light, humidity, temperature, sweat and cigarette smoke. Identical, Side to Side All our soundproofing foam is cut and angled with nearly 100 percent accuracy, leaving you with clean, squared edges. Unlike other companies that manufacture irregular, jagged or mismatched edges, our foam can be aligned perfectly with the next piece to provide professional uniformity in your installation. Noise Reduction Coefficient (NRC) Overall is 0.35 Acoustical foams effectiveness is measured by its Noise Reduction Coefficient, or NRC rating. The NRC of a material can be found by using the Reverberation Room Method (ASTM C423) 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 room without material compared to the room with 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