The HM Series features high quality sound in a reliable 19-inch rackspace device. deliver flexible, robust headphone distribution for studios, practice spaces with premium analog circuitry with an ultra-low noise floor. Split a single stereo single and send it out to twelve headphone outputs, 3 headphone outputs per a channel. It also feature L/R stereo inputs plus L/R stereo outputs for flexibility. 7-LED meters per a channel in addition to the mains. With mute and stereo/2-channel mode switches, the options are endless to what you can use the HM-400 for. Features: L/R Main stereo inputs plus L/R stereo outputs 7-segment LED metering per channel plus Main 3 headphone outputs per channel Aux input on each channel with balance control to mix main and aux signal Mute and stereo/2-ch mode switches per channel 12 total headphone outputs Built-Like-A-Tank?äó construction Get your Mackie HM-400 4-Channel Headphone Amplifier today at the guaranteed lowest price from Sam Ash Direct with our 45-day return and 60-day price protection policy.