Power for the VHD subwoofers is provided by the VHD3200 rack mounted subwoofer amplifier. The unit contains two separate 1600W amplifiers with individual power supplies, signal paths and I/O within a single four rack space chassis. The unit acts as a slave for the VHD2000, which provides audio and control signal, and also functions in the same way for expansion of an ES series system, taking its feed from the external subwoofer output on an EPAK2500R or an ESR/SL3000 amplifier. The 3200 amplifier can also run in bridge mode for maximum bass output driving a single VHD2.21 sub.