York Building Products uses patented Proudfoot molds designed to fit standard block machines insuring the uniformity and acoustical efficiency of each Soundblox® unit. They are fire rated for up to three plus hours and have the same compressive strength (ASTM C-90 conformancy) as a standard hollow concrete masonry unit. Soundblox® get their excellent sound absorption from a unique cavity-slot resonator construction. The funnel shaped slots of the RSR, RSC and Q Type units provide superior acoustical performance. Using a metal septum and fibrous filler in the cavity works to provide higher levels of sound absorption across a wider range of frequencies. The A1 is designed for low frequency absorption and the RSC/RF is for walls requiring vertical reinforcing, insulation or cores for conduit and pipes.

The economical Soundblox® unit may be painted without significant reduction of sound absorption and may also be produced as a groundface or fluted unit. Whether they are painted, produced with colored pigments or left in their original state the Soundblox® unit is an excellent choice for industrial applications, gymnasiums, highway noise barriers and other comparable installations.