Last updated 1/7/2021 (first update). Last updated 18/7/2021 (added information about AKG K7XX and testing details).
TLDR: The MOTU M4 is a straightforward plug and play USB compliant audio interface that works well with Linux 5.10 and 5.11+. Simply connected the device, set my computer to output via the M4 (popped up in sound settings very quickly) and enjoyed its high quality audio. By default, my system is outputting to all 4 channels. When using a program like Audacity or Ardour, the MOTU M4 inputs and outputs would appear easily and individual channels could be designated for recording and playback. Sounds great, records great.
Only one issue at this stage is being unable to output audio properly via Jack. Will update this article when I come across a solution.
The MOTU M4 is a powerful USB class compliant audio interface that is well made and incredibly portable. It provides a high quality clean output and input of audio. It’s a great choice for users on the move, those that want a simple setup and Linux users (along with Mac OS X, iOS and Windows users). MOTU, which stands for Mark of the Unicorn, are the company behind the M4. They’re based in the USA and have been at it since the 1980s.
Information about the MOTU M4 and its Linux compatibility is sparse at points. Thus, wanted to contribute to the cause to help more Linux users with their decision to get a MOTU M4 and using a MOTU M4 on Linux systems. Naturally your experience may differ but in my experience the MOTU M4 has been reasonably trouble free and easy to use with Linux.
This article will be updated when I have the time and interest to do so. Not making any promises. May update it with stats such as latency, multiple long term experiences, guides and configurations. For my uses thus far, it has performed very well. Initially this article will focus on the user experience and capabilities, highlighting that this device does work well on Linux.
What has been tested:
- Plug and play with Linux 5.10+ and 5.11+ with Manjaro Cinnamon.
- The XLR/TRS combo on channels 1-2 and line-in on channels 3-4.
- All outputs.
- Use with numerous audio programs.
What hasn’t been tested:
- No worthwhile measurements of latency or other audio specs yet.
Plug and Play Experience
When using Linux 5.10 or 5.11 with Manjaro Cinnamon, the MOTU M4 worked well by simply plugging it in with no special configurations required.
On 5.10 and 5.11 Manjaro Cinnamon sound settings, the MOTU M4 appears as “M Series” on the list of outputs.
Be default and when external of a DAW or professional audio program, my system would output audio to all channels. In my case this was fine as channels 3-4 are connected to a mixer.
When loading up Audacity or Ardour, all individual inputs and outputs could be selected and designated easily. Multiple audio programs had no problem with using the M4’s multiple input and output channels.
Jack did not work out of the box though. Jack had troubles identifying the outputs with the M4, thus I wouldn’t get any sound playback. This was only when using Jack though as the default Pulse / Alsa combination could identify outputs and inputs fine.
All of the hardware features worked fine out of the box. There was no distortion, pops or crackles.
Build Quality, Construction and Durability
The case is made of metal and feels sturdy in your hand. All of the knobs sit firmly in position.
The bottom of the unit has four rubber feet that help it stay in position. Some users reported it could move a bit, though I found it didn’t really move at all on a wooden table or laminated table with day to day use.
The device continues working at different angles with no interruptions.
The M4 sounds fantastic, whether you’re recording or listening.
The headphone output drives lower ohm and higher ohm headphones well. I have tested the MOTU M4 with the following headphones:
- PSB M4U2 (32 ohms)
- Beyerdynamic DT 770 Pro (250 ohms)
- AKG K7XX (62 ohms)
With each of these headphones, music sounded rich and detailed. For testing, listened to lossless audio files and YouTube audio. The audio in films sounded immersive. To test this, I watched HD videos with high quality audio, along with videos from YouTube. There was no noticeable distortion when listening with any of these headphones. I have not had the chance to try the audio interface with 600 ohm headphones.
Recordings with dynamic and large diaphragm condenser microphones sounded great.
Recording with the U Bass from Kala sounded fantastic. There was no noticeable distortion with any recordings.
The experience of using the MOTU M4 on Linux has been fantastic. Plug and play worked well, with Linux 5.10+ and 5.11+ instantly identifying the device and allowing playback.
The sound quality is great and the noise is low. The interface is built well and provides 4 inputs and 4 outputs for easy recording, controlling and listening.
While not Linux related, there are a few hardware elements that leave something to be desired. There is no hardware volume control for channels 3-4. There is only one headphone output which is hardwired to the outputs of channel 1-2. Lack of a volume control or headphone output on channels 3-4 can be resolved by using an external headphone amp, mixer or similar.
At this stage the only issue experienced was Jack being unable to identify the outputs. For my use case, the Pulse / Alsa combination could identify inputs and outputs fine, working great for recording and listening. Will review this element again when time allows.
Overall the MOTU M4 is fantastic on Linux, with its competitive pricing, multiple inputs / outputs and high quality audio for when you’re listening or recording. Being powered over USB, this allows users to produce and enjoy professional level audio when they’re on the move. A great addition for a small studio, independent artist, content producer or audio lover.