The VHD4.18 is a quad 18" subwoofer system, comprising of four individual loudspeaker cabinets. The objective is to make the system easy to transport and setup. When assembled, the VHD4.18 system becomes a high efficiency neodymium subwoofer system with immense output. The system was designed with very high sensitivity in mind; it provides 110 dB at 1W/1m and a tremendous output of 149dB when running at full power Each cabinet incorporates a large port area that becomes an optimized horn aperture when all four cabinets are stacked together. The quad 18" subwoofer system delivers extreme output and controlled low frequency resolution.