MOTU M4 audio interface: features and spec-based rating

MOTU’s M4 is a USB audio interface with 4 inputs and 4 outputs.

An audio interface is the equipment that brings the sound of microphones and instruments into the computer and sends the computer’s sound out to headphones and speakers.

In this article we rate it on 5 criteria using only the specifications the manufacturer publishes, and show how it ranks among the 23 audio interfaces we compare.

Disclosure: This site takes part in affiliate programs. Specifications are as of the date we checked them and can change.

Figure: SoundBounty

Summary

Among the 23 audio interfaces, M4 is rank S. The ranks run S, A, B and C, and S is the top. Averaging the scores for each criterion (out of 5) gives 4.2.

Strengths

• Microphone input quality (EIN -129dBu / DR 115dB, 4 points): It records a microphone with little noise and a good level.
• Ease of streaming (loopback: yes, 5 points): You can stream the computer’s sound and your microphone together.
• Ease of recording guitar and other instruments (2 Hi-Z inputs, 4 points): You can plug in a guitar or bass directly and record.
• Number of inputs and outputs (8 analog inputs and outputs, 5 points): It has many inputs and outputs, so you can record several microphones and instruments at once.

Who it suits: judging from the specifications, it suits people who want to record singing and narration cleanly with little noise; people who want to stream the computer’s sound (BGM and game sound) together with a microphone; people who want to plug in a guitar or bass directly.

Main features of M4

An ESS Sabre32 DAC with 120 dB output

It uses the same ESS Sabre32 Ultra conversion technology as audio interfaces costing thousands of dollars, and the dynamic range of the main outputs is published as 120 dB. The headphone output is also driven by an ESS converter. The EIN of the microphone input is -129 dBu.

A color LCD level meter

The color LCD on the body shows level meters for all inputs and outputs. MOTU claims it is “the only one in this class”, and it makes it easy to match the recording level by eye.

Four inputs, four outputs and MIDI

It has two combo inputs that take a microphone, a line signal or a guitar, two line inputs, four line outputs (and also four RCA outputs) and MIDI in and out. You can connect synthesizers and drum machines together as well.

Loopback and low latency

The driver’s loopback function lets you stream or record the computer’s sound together with a microphone or guitar (on a Mac it is available with an optional driver). The round-trip latency is published as 2.5 ms at 96 kHz with 32 samples. Performer Lite, Ableton Live Lite and 6 GB of loop material are included.

Where it is useful

• Recording several sounds together, such as singing, guitar and synthesizers
• Combining the computer’s sound and your voice for streaming or podcasts
• Recording alone while watching the level meters

Rating by criterion

Microphone input quality: 4 / 5

How quietly and how loudly enough it can record a microphone (low noise, gain range and so on).

M4: EIN -129dBu / DR 115dB. That is a high rating among the products we compared. It records a microphone with little noise and a good level.

Ease of streaming: 5 / 5

Whether it has a function (loopback) that lets you stream the computer’s sound (BGM and game sound) together with a microphone voice.

M4: loopback: yes. That is a high rating among the products we compared. You can stream the computer’s sound and your microphone together.

Ease of recording guitar and other instruments: 4 / 5

The number of inputs (Hi-Z) that take a guitar or bass directly.

M4: 2 Hi-Z inputs. That is a high rating among the products we compared. You can plug in a guitar or bass directly and record.

Number of inputs and outputs: 5 / 5

The number of inputs for microphones and instruments, and outputs for speakers and the like.

M4: 8 analog inputs and outputs. That is a high rating among the products we compared. It has many inputs and outputs, so you can record several microphones and instruments at once.

Features for production: 3 / 5

Features for production such as MIDI ports, built-in effect processing (DSP) and digital I/O.

M4: 1 of 3. That is a standard rating among the products we compared.

The gray marks in the figure below (the dotted line on the pentagon) show the average of the 23 products we compared. Price is not part of the score.

How we score (Audio interfaces)

Criterion	Basis	5 pt	4 pt	3 pt	2 pt	1 pt
Microphone input quality	Quietness (EIN), gain range and dynamic range	Average 4.5 or more	3.5 or more	2.5 or more	1.5 or more	Under 1.5
Ease of streaming	Loopback (send the computer's sound together with the microphone for streaming or recording)	Yes	—	—	—	No
Ease of recording guitar and other instruments	Number of inputs that take a guitar or bass directly (Hi-Z)	3 or more	2	1	—	None
Number of inputs and outputs	Analog inputs plus outputs (headphones excluded)	≥8	≥6	≥4	≥3	<3
Features for production	Built-in DSP, MIDI ports and digital I/O	All 3	2	1	—	None

Scored only on the body specifications published by the manufacturer and the functions listed on the product page. Price and bundled software are not part of the score. "Microphone input quality" is the average of three scores: quietness (EIN: 5 points at -130 dBu or lower, 4 at -129, 3 at -128, 2 at -127), gain range (5 at 72 dB or more, 4 at 65, 3 at 57, 2 at 54) and dynamic range (5 at 118 dB or more, 4 at 116, 3 at 112, 2 at 108). It is scored when two or more numbers are published. "Ease of streaming" depends on whether the interface has loopback, which sends the BGM or game sound playing on the computer to the streaming software together with your voice.

M4 connection and getting started

Connection	USB-C (USB 2.0, and also works with a computer that has USB Type-A) to the computer. It also supports iOS (an adapter and a USB hub with power are needed)
Power	Runs on USB power (with a power switch)
In the box	USB cable
Other	Supported operating systems (spec page): macOS 12 or later and Windows 11 23H2 or later. Bundled software: MOTU Performer Lite, Ableton Live Lite and 6 GB of loop material

Checked on the manufacturer’s official pages on September 27, 2026.

Compared with other audio interfaces

Click a heading to sort. On a phone, the table scrolls sideways.

Before you buy

• It has loopback. When streaming, you can send the computer’s sound and your microphone voice together.
• It has 4 inputs in total for microphones and instruments. Check that the number you want to record at the same time does not exceed the number of inputs.
• It has 2 Hi-Z inputs that take a guitar or bass directly. When you record without effects pedals or an amplifier, you plug into a Hi-Z input.
• It has MIDI ports. You can connect keyboards and gear that have MIDI jacks directly.

Read next

• Babyface Pro FS: features and rating (rank S)
• M6: features and rating (rank S)
• US-2x2HR: features and rating (rank A)
• Clarett+ 2Pre: features and rating (rank A)