Headphone Monitor Mixer Mackie HM-4 Black — 4-channel, 6.3mm, DC powered

The Mackie HM-4 Black is a compact 4-channel headphone monitor mixer designed for personal monitoring and small live or studio setups. It accepts a stereo input and provides four independent headphone outputs via 6.3 mm connectors, delivering clear monitoring with a simple, space-saving footprint (109 × 58 × 21 mm). The unit is DC powered and built to split a single stereo signal into multiple headphone mixes while maintaining adequate channel separation and impedance levels for common headphones.

Advantages

The HM-4 offers four independent channels that allow simultaneous monitoring for multiple listeners without complex routing. With a 10 kΩ input impedance and 47 Ω output impedance it is engineered to work with a wide range of headphones and source equipment. Compact dimensions and straightforward controls make the unit easy to place on stage, in a rehearsal room, or on a studio desktop. The 6.3 mm headphone jacks are compatible with standard professional headphones and adapters.

Suitable for

• Home and project studio headphone distribution
• Small live performances and stage monitoring for performers
• Rehearsal rooms and practice sessions with multiple listeners
• Cue mixes for recording sessions and small broadcast setups
• Shared headphone listening for multimedia playback (e.g., watching video or reviewing takes)

Key specifications

• Channels: 4 independent headphone outputs
• Headphone connector: 6.3 mm (1/4") jacks
• Input impedance: 10 kΩ
• Output impedance: 47 Ω
• Channel separation: 22 dB
• Power: DC powered (external DC supply required)
• Dimensions: 109 × 58 × 21 mm

How to use

Connect a stereo source to the mixer's input, attach headphones to the 6.3 mm outputs, and power the unit with the appropriate DC adapter. Adjust the input level from the source device to avoid clipping; the HM-4 distributes the incoming stereo signal to each headphone channel. Position the mixer on a desk, stage floor, or rack shelf where it is convenient for the performers or listeners to plug in and monitor. No complex setup is required—this mixer acts as a straightforward splitter with individual level control per channel.

Usage recommendations

For best results, use headphones with nominal impedance above the output impedance to ensure proper damping and frequency response. When deploying on stage or in rehearsal spaces, place the unit in a protected, dry area and use a stable, regulated DC adapter that matches the manufacturer's voltage and polarity specifications.