QuietFiber is a form of mineral wool that is compressed into 4pcf, 6pcf or 8pcf, semi-rigid slabs. They are available in flat sections with lengths and widths measuring either 72″ x 16” or 72″ x 24”. They come in a black-faced finish.
Most of the time walls fall short in the lower frequency ranges of attenuation. This is why a lot of sound can still be heard through a highly rated STC wall; those sounds are outside of the range of the STC test. Using QuietFiber in greater thicknesses and densities dramatically raises both the TL and the low frequency attenuation of walls, ceilings and floors. In most cases by an additional 4-5 dB over fiberglass treated assemblies. The gains can be even higher when you look at the TL of the frequencies below 125 Hz and above 4kHz.