
Mackie HM-400 4-channel Headphone Amplifier
HM Series Headphone Amplifiers ExpandYour Versatility Perfect for studios, practice spaces, quiet stages, and more, the HM Series offers everything you need whether it is just splitting a single signal to your band, or more complex headphone distribution. Flexible Headphone amplification Whether you need to expand your home studio headphone monitoring capability or add robust cue mix distribution, the affordable HM Series offers the sound quality, reliability, and flexibility you need to expand your setup. The ultra-compact HM-4 offers a simple yet effective way to split a single stereo signal out into four pairs of headphones. Perfect for quickly splitting a phones mix in the studio or even crowding around a tablet to watch a movie at home. The two 19" rackmount models, the HM-400 and HM-800, deliver flexible, robust headphone distribution for studios, practice spaces and more. Features Great-sounding, reliable headphone amplification superior Excellent Sound Quality Premium analog circuitry and design delivers an ultra-low noise floor and high headroom. Choice Ultra-Flexible From a simple yet effective way to split a single stereo signal out to four pairs of headphones to robust headphone distribution, the HM Series offers a wide range of options to suit your needs. rugged Built-Like-A-Tank™ With a heavy-gauge steel chassis, long wear potentiometers and switches Mackie HM-400 Overview 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. One stereo main input via XLR and 1/4" jacks can be mixed with a per-channel 1/4" stereo aux input. Each channel offers 2-band EQ for quick tone shaping, stereo balance or main/aux input mix control, and output level adjustments. Also on each channel are switches for muting left and/or right signals and operating in stereo or mono. 7-segment LED meters display main input and per-channel output levels. The HM-400 ships with an IEC power cable and occupies 1 RU in a standard 19" rack. Distribute signal to up to twelve pairs of headphones Occupies 1 RU One stereo main input via XLR or 1/4" jacks One 1/4" stereo aux input per channel One stereo main output via XLR or 1/4" jacks Three 1/4" headphone outputs—one on the front panel and two on the rear—per channel fed by an output level control 2-band EQ per channel for quick treble and bass adjustments Per-channel Balance knob allows control of left/right level balance or aux/main input mix Switches on each channel for L/R mute and St/2-Ch (stereo/mono) mode 7-segment LED metering for input and each output channel Heavy-gauge steel chassis for rugged durability Mackie HM-400 Specs Number of Channels 4 Input Connections 2 x XLR 3-pin balanced (one stereo pair) 2 x 1/4" TRS balanced (one stereo pair, also accepts 1/4" TS unbalanced) 1 x 1/4" TRS stereo unbalanced for main input 4 x 1/4" TRS stereo unbalanced for aux inputs Output Connectors 2 x XLR 3-pin balanced (one stereo pair) 2 x 1/4" TRS balanced (one stereo pair, also accepts 1/4" TS unbalanced) 12 x 1/4" TRS stereo unbalanced headphone outputs Maximum Input Level Main Input: +15 dBu Aux Input: +20 dBu Maximum Output Level Headphone Outputs: 550 mW per channel at 47 Ohms (+21 dBu) Input Impedance Main Input: 20 kOhms balanced, 10 kOhms unbalanced Aux Input: 10 kOhms unbalanced Output Impedance Headphone Outputs: 3 Ohms unbalanced Gain Range Main Input: -66 to +18 dBu Function Controls Power on/off Main level knob L/R mute switches per channel Stereo/2-Ch switches per channel 2-band EQ per channel Balance knob per channel Output knob per channel Frequency Response 20 Hz to 20 kHz (±1 dB) THD Noise -66 dB CMRR Main Input: >42 dB at 1 kHz Display 1 x input level meter 4 x output level meters Power Requirement 100 to 120 VAC, 50/60 Hz, 24 W 220 to 240 VAC, 50/60 Hz, 24 W Power Connector 1 x 3-pin IEC male, 250 VAC, 10 A Construction Material Heavy-gauge steel chassis Dimensions (H x W x D) 1.8 x 19.0 x 8.8" / 46 x 483 x 224 mm Weight 8 lb / 3.6 kg Packaging Info Package Weight 10.5 lb Box Dimensions (LxWxH) 20.8 x 10.6 x 4.1"