XDM300/1 - Monoblock, Class D, Marine Subwoofer Amplifier, 300 W Monoblock Class D Marine Subwoofer Amplifier, 300 W x 1 @ 2 / 200 W x 1 @ 4 - 14.4V This little monoblock powerhouse employs our high-speed NexD switching design to achieve unprecedented efficiency and amazing power output for its size. It is small enough to fit in most tight space applications, smaller boats, and UTV s (in a weather-tight compartment). Designed boat installations, the XDM300/1 is built with marine-grade materials and features an exclusive, dual-mode input filter for noise-free performance in boats. Automatic turn-on capability (via signal sensing or DC-offset sensing) is also onboard for easy factory system upgrades. Targeted specifically for subwoofer applications, the XDM300/1 includes a variable slope low-pass filter with continuously variable cutoff frequency selection from 50-500 Hz. With the addition of an optional MHD-RLC (water-resistant) remote level controller (sold separately), the amplifier's level can be adjusted directly from the captain s chair. Finished in a sleek, black powder-coat, all controls are protected beneath a gasketed, removable top cover for easy access.