RCF 4PRO 8001-S subwoofer integrates an RCF Precision Series low distortion, high power woofer a low pass / high pass output crossover filter in a small size, robust baltic birch plywood enclosure. The result is a compact, high power subwoofer remarkable for extended output and low distortion. This new high power 18” inch woofer is the result of the latest refinement in years of RCF experience in compact subwoofers design and manufacture, resulting in a fast and controlled reproduction of the bass frequency range.