The Mackie HM-4 is a 4-way headphone amplifier designed to provide simple and effective headphone amplification for artists, musicians, and engineers monitoring through headphones in home, project, commercial, and mobile-recording studios. Its single 1/4″ TRS stereo input and four 1/4″ TRS stereo outputs allow you to distribute a stereo source to up to four pairs of headphones.

Each output is controlled via a dedicated level knob, allowing varied listening volumes for each person. The compact heavy-gauge steel chassis offers rugged durability and a convenient power status indicator on its front panel. Use the included 12 VDC power supply to power the HM-4.

The Mackie HM-400 is a rack-mountable, 4-channel headphone amplifier designed to provide versatile headphone amplification for artists, musicians, and engineers monitoring through headphones in live stage applications and home, project, commercial, and mobile-recording studios. It features a stereo main output via XLR and 1/4″ jacks and twelve 1/4″ TRS stereo headphone outputs—three per channel—fed by a customizable blend of inputs.

The Mackie HM-800 is a rack-mountable, 8-channel headphone amplifier designed to provide versatile headphone amplification for artists, musicians, and engineers monitoring through headphones in live stage applications and home, project, commercial, and mobile-recording studios. It features two stereo main outputs via four 1/4″ jacks and sixteen 1/4″ TRS stereo headphone outputs—two per channel—fed by a customizable blend of inputs.

Two stereo main inputs via four 1/4″ jacks can be combined with a per-channel 1/4″ stereo aux input. Each channel offers stereo/mono mode switching, input selection, and output level adjustments. 7-segment LED meters display main input and per-channel output levels.