The VSB 218 is a very powerful 2 x 18″ subwoofer that is suitable for medium/large sized indoor events , or outdoor events where medium/long throw bass is desirable. Our „V“ internal structure makes this box extremely strong and minimises the standing waves which cause booming in other designs. The VSB 218 was designed to reproduce very low frequencies, with a medium projection, as a single box. But when coupled you will achieve a high output long throw sub. We use a minimal amount of processing (in our own processor) simply to extend the low frequency response while preventing over excursion of the cone. This processing is inaudible and makes these boxes almost indestructible. The VSB 218 has a useable frequency range from 30Hz-100Hz. 1 x VSB 218 will give you 101dB sensitivity @1w/1m. Maximum continuous S PL 128dB @1m. Coupling 4 x VS B 218 gives a maximum continuous S PL 137dB @1m.