Mackie

Mackie HM-400 4-Channel Headphone Amplifier Rackmount

4.1 (55 reviews)

Maximize Your Monitoring Capabilities with the Mackie HM-400 Headphone Amplifier The Mackie HM-400 is a versatile 4-channel headphone amplifier, designed for professional audio environments. With 12 headphone outputs, individual channel controls, and flexible input options, the HM-400 delivers ex...

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*Price sourced from Amazon.com. Last updated:Jul 14, 2026.Price and availability are subject to change.

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Overview

Maximize Your Monitoring Capabilities with the Mackie HM-400 Headphone Amplifier

The Mackie HM-400 is a versatile 4-channel headphone amplifier, designed for professional audio environments. With 12 headphone outputs, individual channel controls, and flexible input options, the HM-400 delivers exceptional sound quality and control. Perfect for studios, houses of worship, and practice spaces.

Specifications:

  • Channels: 4
  • Headphone Outputs: 12 (3 per channel)
  • Inputs: L/R Main Stereo Inputs, Aux Input per channel
  • Outputs: L/R Main Stereo Outputs
  • Controls: Level Control, Balance Control, Mute Switch, Stereo/2-ch Mode Switch per channel
  • Mounting: 19” Rackmount

Key Features

L/R main stereo inputs plus L/R stereo outputs

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

Specifications

Brand
Mackie
Model Name
HM-400
Channels
4
Total Headphone Outputs
12
Headphone Outputs Per Channel
3
Main Stereo Inputs
L/R
Main Stereo Outputs
L/R
Aux Input Per Channel
Yes
Aux Input Control
Balance
Channel Switches
Mute, Stereo/2-ch Mode

Pros & Cons

👍 Pros

  • Features a comprehensive set of L/R main stereo inputs and outputs, allowing for flexible signal routing within a professional setup.
  • Equipped with three headphone outputs per channel, providing ample monitoring points for multiple musicians or engineers.
  • Includes an Aux input on each channel with a balance control, enabling precise mixing of main and auxiliary signals for individual monitoring.
  • Offers Mute and Stereo/2-ch Mode switches per channel, which provides greater control over individual headphone mixes.
  • Boasts a total of 12 headphone outputs, making it highly suitable for large ensemble recording sessions or live monitoring scenarios.

👎 Cons

  • The features do not specify the power output per headphone channel, which might be a concern for driving high-impedance headphones.
  • Without explicit details on the signal-to-noise ratio or distortion, assessing its sonic transparency beyond basic functionality is difficult.
  • The rackmount form factor means it is not designed for portable, on-the-go setups, requiring a dedicated rack space.
  • While it has many outputs, the lack of individual channel EQ controls means tonal adjustments must happen upstream.
  • Input impedance details are not provided, which could be a factor when connecting various line-level sources for optimal gain staging.

Frequently Asked Questions

The Mackie HM-400 offers a total of 12 headphone outputs, with three outputs available for each of its four channels, supporting a large monitoring setup.
Yes, each channel features an Aux input with a dedicated balance control, allowing you to blend the main and auxiliary signals to create custom mixes for each headphone output.
Each channel on the HM-400 is equipped with Mute and Stereo/2-ch Mode switches, providing specific control over the audio sent to the headphone outputs for that channel.
The Mackie HM-400 includes L/R main stereo inputs and L/R stereo outputs, facilitating integration into a standard studio or live sound signal chain.
With its extensive headphone outputs and channel controls, the HM-400 is well-suited for studio recording sessions, live stage monitoring, and broadcast environments where multiple performers or engineers require individual mixes.
The HM-400 features a rackmount design, indicating it is intended for installation in a standard equipment rack rather than frequent portable transport.