Mackie HM-400 – 4-Channel Rackmount Headphone Amplifier for Studio & Live Monitoring

The Mackie HM-400 is a professional 4-channel headphone amplifier designed for studios, rehearsal rooms and live monitoring setups requiring clear, powerful and flexible headphone distribution. With robust build quality, per-channel controls and multiple output options, it ensures every performer hears exactly what they need during tracking or performance.

Key Features

• 4 independent headphone channels: Each channel includes three headphone outputs, giving you a total of twelve outputs for multi-user monitoring.
• Flexible input mixing: A main stereo input can be combined with per-channel 1/4″ aux inputs to create customized mixes for each performer.
• 2-band EQ per channel: Shape tone quickly and adapt to different headphones or listening preferences.
• Stereo/mono & mute switches: Adjust channel behavior with dedicated controls for left/right mute, stereo/mono and main/aux blend.
• Clear metering: 7-segment LED meters provide at-a-glance feedback for both the main input and each channel’s output level.

Customer Benefits

The HM-400 gives studios and stage setups dependable and highly customizable monitoring. Performers can dial in the exact mix and tone they need, while engineers can distribute a clean, consistent signal to multiple listeners without complexity. Its rugged rackmount chassis ensures long-term reliability for professional use.

Quick Specs

• Main inputs: Stereo XLR + 1/4″
• Aux inputs: 4 × per-channel 1/4″ stereo aux
• Headphone outputs: 12 × 1/4″ stereo (three per channel)
• Controls per channel: Output level, 2-band EQ, stereo/mono, left/right mute, balance or main/aux mix
• Metering: 7-segment LED meters for main input and each channel
• Form factor: 1U rackmount

What’s in the Box

• Mackie HM-400 headphone amplifier
• Power cable
• Documentation

Use Cases / Ideal For

Recording studios, podcast teams, rehearsal spaces, small performance venues, broadcast environments and multi-musician tracking sessions.

Compatibility

Works with standard headphones, audio interfaces, mixers and signal distribution systems using XLR or 1/4″ connections.

Pros & Cons

✅ Pros:

• Three headphone outputs per channel for flexible multi-user setups
• Per-channel EQ and mix control
• Robust rackmount design
• Clear metering for accurate level monitoring

⚠️ Cons:

• No 3.5 mm headphone outputs—adapters may be required
• Requires rack space in fixed installations

The Mackie HM-400 provides powerful, adaptable and reliable headphone monitoring, making it a trusted choice for professional studios and live environments — available at Soundium.