MOTU M Series User manual

™
M4
1280 Massachusetts Avenue
Cambridge, MA 02138
Business voice: [phone]
Business fax: [phone]
Web site: www.motu.com
Tech support: www.motu.com/support
Title Page
User Guide
M2 |
™

SAFETY PRECAUTIONS AND ELECTRICAL REQUIREMENTS FOR THE M2 AND M4 (“PRODUCT”)
CAUTION! READ THIS SAFETY GUIDE BEFORE YOU BEGIN INSTALLATION OR OPERATION. FAILURE TO COMPLY WITH SAFETY INSTRUCTIONS
COULD RESULT IN BODILY INJURY OR EQUIPMENT DAMAGE.
HAZARDOUS VOLAGES: CONTACT MAY CAUSE ELECTRIC SHOCK OR BURN. TURN OFF UNIT BEFORE SERVICING.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR OTHER MOISTURE.
CAUTION: TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL.
WARNING: DO NOT PERMIT FINGERS TO TOUCH THE TERMINALS OF PLUGS WHEN INSTALLING OR REMOVING THE PLUG TO OR FROM THE OUTLET.
WARNING: IF NOT PROPERLY GROUNDED THE MOTU PRODUCT COULD CAUSE AN ELECTRICAL SHOCK.
IMPORTANT SAFEGUARDS
1. Read these instructions. All the safety and operating instructions should be read before operating the product.
2. Keep these instructions.These safety instructions and the product owner’s manual should be retained for future reference.
3. Heed all warnings. All warnings on the product and in the owner’s manual should be adhered to.
4. Follow all Instructions. All operating and use instructions should be followed.
5. Do not use the product near water.
6. Cleaning - Unplug the product from the computer and clean only with a dry cloth. Do not use liquid or aerosol cleaners.
7. Ventilation - Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
8. Heat - Do not install the product near any heat sources such as radiators, heat registers, stoves, or another apparatus (including an amplifier) that produces heat.
9. Overloading - Do not overload wall outlets and extension cords as this can result in a risk of fire or electrical shock.
10. Power cord - Protect the product power cord from being walked on or pinched by items placed upon or against them. Pay particular attention to cords and plugs, convenience receptacles, and the point where they exit
from the unit.
11. Power switch - Install the product so that the power switch can be accessed and operated at all times.
12. Disconnect - The main plug is considered to be the disconnect device for the product and shall remain readily operable.
13. Accessories - Only use attachments/accessories specified by the manufacturer.
14. Placement - Use only with the cart, stand, tripod, bracket or table specified by the manufacturer, or sold with the product.When a cart is used, use caution when moving the cart/apparatus combination to avoid injury
from tip-over.
15. Surge protection - Unplug the product during lightning storms or when unused for long periods of time.
16. Servicing- Referall servicing to qualified servicepersonnel.Servicing is requiredwhen the producthas been damaged in anyway, such as when a power-supplycord or plug is damaged, liquid has beenspilled or objects
have fallen into the product, the product has been exposed to rain or moisture, does not operate normally, or has been dropped.
17. Power Sources - Refer to the manufacturer’s operating instructions for power requirements. Be advised that different operating voltages may require the use of a different line cord and/or attachment plug.
18. Installation - Do not install the product in an unventilated rack, or directly above heat-producing equipment such as power amplifiers. Observe the maximum ambient operating temperature listed below.
19. Power amplifiers- Never attach audio power amplifier outputs directly to any of the unit’s connectors.
20. Replacement Parts -When replacement parts are required, be sure the service technician has used replacement parts specified by the manufacturer or have the same characteristics as the original part. Unauthorized
substitutions may result in fire, electric shock or other hazards.
21. Safety Check - Upon completion of any service or repairs to this MOTU product, ask the service technician to perform safety checks to determine that the product is in safe operating conditions.
ENVIRONMENT, HEAT AND VENTILATION
OperatingTemperature: 10°C to 40°C (50°F to 104°).The product should be situated away from heat sources or other equipment that produces heat. When installing the product in a rack or any other location, be sure there
is adequate space around the product to ensure proper ventilation. Improper ventilation will cause overheating and can damage the unit.
TO REDUCE THE RISK OF ELECTRICAL SHOCK OR FIRE
Do not handle the power cord with wet hands. Do not expose this apparatus to rain or moisture. Do not place objects containing liquids on it.

iii
Contents
3Contents
5Quick Start Guide
7M2 Quick Reference
8M4 Quick Reference
9Packing List and System Requirements
11 Software Installation
15 Hardware Installation
19 Working with Host Audio Software
23 Troubleshooting
25 Audio Specifications
27 Index

About the Mark of the Unicorn License Agreement and Limited Warranty on Software
TO PERSONSWHO PURCHASE OR USE THIS PRODUCT: carefully read all the terms and conditions of the “click-wrap”license agreement presented to you when you install the software.
Using the software or this documentation indicates your acceptance of the terms and conditions of that license agreement.
Mark of the Unicorn, Inc. (“MOTU”) owns both this program and its documentation. Both the program and the documentation are protected under applicable copyright, trademark, and
trade-secret laws.Your right to use the program and the documentation are limited to the terms and conditions described in the license agreement.
REMINDER OF THE TERMS OF YOUR LICENSE
This summary is not your license agreement, just a reminder of its terms.The actual license can be read and printed by running the installation program for the software.That license
agreement is a contract, and clicking “Accept”binds you and MOTU to all its terms and conditions. In the event anything contained in this summary is incomplete or in conflict with the
actual click-wrap license agreement, the terms of the click-wrap agreement prevail.
YOU MAY:(a) use the enclosedprogramona single computer;(b) physicallytransfer theprogramfrom one computerto another providedthat the program is used ononly one computer
ata time and thatyouremoveanycopiesof the programfrom the computer from which theprogramis being transferred;(c)makecopies ofthe programsolely for backuppurposes.You
must reproduce and include the copyright notice on a label on any backup copy.
YOU MAY NOT: (a) distribute copies of the program or the documentation to others; (b) rent, lease or grant sublicenses or other rights to the program; (c) provide use of the program in a
computer service business, network, time-sharing, multiple CPU or multiple user arrangement without the prior written consent of MOTU; (d) translate, adapt, reverse engineer,
decompile, disassemble, or otherwise alter the program or related documentation without the prior written consent of MOTU.
MOTU warrants to the original licensee that the disk(s) on which the program is recorded be free from defects in materials and workmanship under normal use for a period of ninety (90)
days from the date of purchase as evidenced by a copy of your receipt. If failure of the disk has resulted from accident, abuse or misapplication of the product, then MOTU shall have no
responsibility to replace the disk(s) under this LimitedWarranty.
THIS LIMITEDWARRANTY AND RIGHT OF REPLACEMENT IS IN LIEU OF, ANDYOU HEREBYWAIVE, ANY AND ALL OTHERWARRANTIES, BOTH EXPRESS AND IMPLIED, INCLUDING BUT NOT
LIMITEDTOWARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.THE LIABILITY OF MOTU PURSUANTTOTHIS LIMITEDWARRANTY SHALL BE LIMITED TO THE
REPLACEMENT OFTHE DEFECTIVE DISK(S), AND IN NO EVENT SHALL MOTU OR ITS SUPPLIERS, LICENSORS, OR AFFILIATES BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES,
INCLUDING BUT NOT LIMITEDTO LOSS OF USE,LOSSOF PROFITS, LOSS OF DATA OR DATA BEING RENDEREDINACCURATE, OR LOSSES SUSTAINED BYTHIRD PARTIES EVENIF MOTUHASBEEN
ADVISED OFTHE POSSIBILITY OF SUCH DAMAGES.THISWARRANTY GIVESYOU SPECIFIC LEGAL RIGHTSWHICH MAY VARY FROM STATETO STATE. SOME STATES DO NOT ALLOW THE
LIMITATION OR EXCLUSION OF LIABILITY FOR CONSEQUENTIAL DAMAGES, SOTHE ABOVE LIMITATION MAY NOT APPLYTOYOU.
UPDATE POLICY
To be eligible to obtain software and firmware updates for your MOTU product, you must register your MOTU product at motu.com/register.
COPYRIGHT NOTICE
Copyright © 2019 by Mark of the Unicorn, Inc. All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into
any human or computer language, in any form or by any means whatsoever, without express written permission of Mark of the Unicorn, Inc., 1280 Massachusetts Avenue, Cambridge,
MA, 02138, U.S.A. Digital Performer, Performer, Mark of the Unicorn, MOTU and the unicorn silhouette logo are trademarks of Mark of the Unicorn, Inc.
LIMITED WARRANTY ON HARDWARE
Mark of the Unicorn, Inc. (“MOTU”) warrants this equipment against defects in materials and workmanship for a period ofTWO (2)YEARS from the date of original retail purchase.This
warranty applies only to hardware products; MOTU software is licensed and warranted pursuant to separate written statements.
If you discover a defect, first write or call MOTU at [phone] to obtain a Return Merchandise Authorization Number. No service will be performed on any product returned without
prior authorization. MOTU will, at its option, repair or replace the product at no charge to you, provided you return it during the warranty period, with transportation charges prepaid, to
MarkoftheUnicorn,Inc.,1280 MassachusettsAvenue,Cambridge,MA 02138.Youmustusethe product’s original packing material for in shipment,and insuretheshipmentforthevalue
of the product. Please include your name, address, telephone number, a description of the problem, and the original, dated bill of sale with the returned unit and print the Return
Merchandise Authorization Number on the outside of the box below the shipping address.
This warranty does not apply if the equipment has been damaged by accident, abuse, misuse, or misapplication; has been modified without the written permission of MOTU, or if the
product serial number has been removed or defaced.
ALLIMPLIEDWARRANTIES,INCLUDINGIMPLIEDWARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TOTWO (2) YEARS FROMTHE
DATE OF THE ORIGINAL RETAIL PURCHASE OF THIS PRODUCT.
THEWARRANTY AND REMEDIES SET FORTH ABOVE ARE EXCLUSIVE AND IN LIEU OF ALL OTHERS, ORAL ORWRITTEN, EXPRESS OR IMPLIED. No MOTU dealer, agent, or employee is
authorized to make any modification, extension, or addition to this warranty.
MOTU IS NOT RESPONSIBLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM ANY BREACH OFWARRANTY, OR UNDER ANY LEGAL THEORY, INCLUDING LOST
PROFITS,DOWNTIME, GOODWILL, DAMAGE OR REPLACEMENTOF EQUIPMENT ANDPROPERTY AND COSTOF RECOVERINGREPROGRAMMING, OR REPRODUCINGANYPROGRAM OR DATA
STORED IN OR USED WITH MOTU PRODUCTS.
Some states do not allow the exclusion or limitation of implied warranties or liability for incidental or consequential damages, so the above limitation or exclusion may not apply to you.
This warranty gives you specific legal rights, and you may have other rights which vary from state to state.
Manual version 1.03

5
Quick Start Guide
Thank you for purchasing an M series USB
interface! Follow these easy steps to get started
quickly.
FOR MAC USERS
1Connect the M2 or M4 to your Mac using the
included USB cable.
☛If your computer has USB-C ports, use a
USB-C to USB-C cable (rated for USB2), or a
USB-C to USB-A adapter, (both sold separately).
2Go to the Apple menu and choose System
Preferences.
3Click Sound and choose the M2 or M4 as the
input and output device.
4Go to Step 5 below.
FOR WINDOWS USERS
1BEFORE you connect the M2 or M4 to your
computer, visit motu.com/m2-start or
motu.com/m4-start to download and install the
Windows driver.
2Connect the M2 or M4 to your PC using the
included USB cable.
☛If your computer has USB-C ports, use a
USB-C to USB-C cable (rated for USB2), or a
USB-C to USB-A adapter, (both sold separately).
3Go to the Windows Sound Control Panel and
choose MOTU M Series as the default input and
output device.
4Go to Step 5 below.
FOR ALL USERS
5Connect speakers and/or a pair of headphones
to the M2 or M4 so you can hear your computer’s
audio output. For speakers, connect them to the
outputs on the back panel.
6You are now ready to start using your M series
interface.
7Visit motu.com/m2-start or motu.com/m4-start
to register your product, download the included
software and watch brief how-to videos, including:
■How to connect a mic, guitar, keyboard or other
line-level audio source.
■How to use your M series interface with your
recording software.
■How to get the most out of your M series
interface.

6
PLEASE REGISTER TODAY
Please visit motu.com/m2-start or
motu.com/m4-start to register your M series
interface and gain access to all the software, virtual
instruments, loops and sounds that are included
with your purchase. Registered users also qualify
for technical support and information about
software updates, so please register today!
Thank you for taking the time to register your new
MOTU product!
FINDING YOUR SERIAL NUMBER
You can find your M series product serial number
on the bottom of the unit and the side of the box.

M2 Quick Reference
1. These two XLR/TRS combo jacks accept a mic cable or a
quarter-inch cable, balanced or unbalanced, from a guitar
or line level source.
2. Use GAIN knob to add up to 60 dB of boost to the input
signal.Watch the input level meter in the LCD while
adjusting gain. Try to adjust gain as high as possible
without clipping, which is indicated by the red rectangle at
the top of the meter.
3. The full-color, high-resolution LCD (160x120 pixels) shows
full-length meters for all inputs and outputs. An
overloaded signal is indicated by a red box at the top of the
signal. If you see the red box, reduce the signal level. A blue
box around the input channel number indicates that
hardware (direct) monitoring (the MON button) is
engaged for that channel.
4. Volume control for the MONITOR outputs on the back
panel.
5. Volume control for headphone output.
6. Connect your headphones here.This signal matches the
signal on the MONITOR outputs on the rear panel, but
volume control (5) is independent.
7. Engage the 48V button to enable phantom power for a
condenser microphone connected to the input.
8. Engage the MON (monitor) button to enable hardware
(direct) monitoring, which routes the channel’s input
signal directly to the outputs and pans the mono signal
evenly across both outputs (1-2). A blue box appears
around the input channel number in the LCD to indicate
that hardware monitoring is engage. Press and hold the
MON button to engage stereo monitoring for both inputs.
In this mode, Input 1 is routed to Output 1 and Input 2 is
routed to Output 2, allowing you to monitor in stereo while
recording in stereo.
9. POWER SWITCH:You can switch off the M2 and turn it back
on without restarting your computer.
10. Connect MIDI gear to these standard MIDI ports.
11. These unbalanced RCA analog outputs mirror the signal on
the quarter-inch outputs (12). You can connect them to a
second set of speakers or other destination.
12. Connect these balanced, DC-coupled quarter-inch outputs
to your studio speakers, PA or other desired audio destina-
tion. They can also accept an unbalanced plug.
Note: the analog outputs are not cross-coupled. Therefore,
when connecting them to an unbalanced input, use aTRS
plug with the ring disconnected. Not floating the negative
terminal will short it to the sleeve ground and cause
distortion.
13. Connect the M2 to your host computer with the supplied
USB-C to USB-A cable. If your computer has USB-C ports,
use a USB-C to USB-C cable (rated for USB2) or a USB-A
adapter (both sold separately).The M2 is powered by its
USB connection to the host computer. For information
about connecting to an iOS device, see “Connecting to an
iOS device”on page 17.
2
10
3 5
678
9
1 4
11 12
13

M4 Quick Reference
1. These two XLR/TRS combo jacks accept a mic cable or a
quarter-inch cable, balanced or unbalanced, from a guitar
or line level source.
2. Use GAIN knob to add up to 60 dB of boost to the input
signal.Watch the input level meter in the LCD while
adjusting gain. Try to adjust gain as high as possible
without clipping, which is indicated by the red rectangle at
the top of the meter.
3. INPUT MONITOR MIX: Controls the balance (relative
volume) between computer output (over USB) and live
inputs being monitored through the hardware using the
MON (monitor) button (10).Turn it counterclockwise to
hear more inputs; turn it clockwise to hear more computer
audio.
4. The full-color, high-resolution LCD (160x120 pixels) shows
full-length meters for all inputs and outputs. An
overloaded signal is indicated by a red box at the top of the
signal. If you see the red box, reduce the signal level. A blue
box around the input channel number indicates that
hardware (direct) monitoring (the MON button) is
engaged for that channel.
5. Volume control for the MONITOR outputs on the back
panel.
6. Volume control for headphone output.
7. Connect your headphones here.This signal matches the
signal on the MONITOR outputs on the rear panel, but
volume control (6) is independent.
8. Engages hardware (direct) monitoring for inputs 3-4 on
the rear panel. See (10) below for more information.
9. Engage the 48V button to engage phantom power for a
condenser microphone connected to the input.
10. Engage the MON (monitor) button to enable hardware
(direct) monitoring, which routes the channel’s input
signal directly to the outputs and pans the mono signal
evenly across both outputs (1-2). A blue box appears
around the input channel number in the LCD to indicate
that hardware monitoring is engage. Press and hold the
MON button to engage stereo monitoring for both inputs.
In this mode, Input 1 is routed to Output 1 and Input 2 is
routed to Output 2, allowing you to monitor in stereo while
recording in stereo.
11. POWER SWITCH:You can switch off the M4 and turn it back
on without restarting your computer.
12. Connect MIDI gear to these standard MIDI ports.
13. These unbalanced RCA analog outputs mirror the signal on
their corresponding quarter-inch outputs (14). You can
connect them to a second set of speakers or other destina-
tions.
14. Connect these balanced, DC-coupled quarter-inch outputs
to your studio speakers, PA or other desired audio destina-
tion. They can also accept an unbalanced plug. Each output
pair is independent and can be found as separate output
pairs in your host software.
Note: the analog outputs are not cross-coupled. Therefore,
when connecting them to an unbalanced input, use aTRS
plug with the ring disconnected. Not floating the negative
terminal will short it to the sleeve ground and cause
distortion.
15. These LINE INPUTS accept either a balanced or unbalanced
plug. Connect a keyboard or other similar line level audio
source.
16. Connect the M4 to your host computer with the supplied
USB-C to USB-A cable. If your computer has USB-C ports,
use a USB-C to USB-C cable (rated for USB2) or a USB-A
adapter (both sold separately).The M4 is powered by its
USB connection to the host computer.
2
12
4 6
7910
11
1 5
15
16
3
8
13 14

CHAPTER
9
1Packing List and
System Requirements
PACKING LIST
The M2 and M4 ship with the items listed below. If
any of these items are not present in the box when
you first open it, please immediately contact your
dealer or MOTU.
■One M2 or M4 audio interface
■USB-C to USB-A cable
■Safety instruction sheet
SYSTEM REQUIREMENTS
■A 1 GHz Intel-based Mac or Pentium-based PC
(or compatible). Faster CPUs are recommended
for best performance.
■2 GB RAM; 4 GB or more recommended.
■macOS 10.11 or later; Windows 7 or later.
■Available high-speed USB 2.0 (or 3.0) port.
■A large hard drive (preferably at least 512 GB).
PLEASE REGISTER TODAY!
Please visit motu.com/m2-start or
motu.com/m4-start to register your M series
interface and gain access to all the software, virtual
instruments, loops and sounds that are included
with your purchase. Registered users also qualify
for technical support and information about
software updates, so please register today!
Thank you for taking the time to register your new
MOTU product!
FINDING YOUR SERIAL NUMBER
You can find your M series product serial number
on the bottom of the unit and the side of the box.

PACKING LIST AND SYSTEM REQUIREMENTS
10

CHAPTER
11
2Software Installation
OVERVIEW
USB audio class-compliant operation . . . . . . . . . . . . . . . . . . .11
Driver installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
M series Control Panel (Windows only). . . . . . . . . . . . . . . . . .12
MIDI I/O on Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
MIDI I/O setup on the Mac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Working with host audio software . . . . . . . . . . . . . . . . . . . . . .14
USB AUDIO CLASS-COMPLIANT OPERATION
Your M Series interface is a USB audio class-
compliant device. This means that you can
connect it to your Mac (running macOS 10.11 or
higher) with a USB cable and use it without
installing any software drivers. The computer
recognizes your M Series interface as a USB audio
device and makes its inputs and outputs available
to your host audio software. Basic settings, such as
the hardware’s sample rate, are made in either your
host software.
☛In this scenario, your M Series interface
provides basic audio input and output, and no
software driver installation is necessary. Use the
Mac’s Audio MIDI Setup utility to manage your M
Series interface audio inputs and outputs for your
Mac.
Connection to iOS devices (iPad and iPhone)
Audio-class compliant operation allows you to
connect your M Series interface to any iOS device
with a standard camera connection kit adapter.
The M Series interface then provides multi-
channel audio I/O to your audio apps. Use your
audio app to configure the number of available
audio channels.
☛For iOS devices with a USB-C port, a USB-C
to USB-C cable is required (sold separately).
☛For iOS devices with a Lightning port, an
Apple Lightning to USB3 Camera Adapter is
required (sold separately).
DRIVER INSTALLATION
Driver installation is required for either of the
following scenarios:
■You are using a PC running Windows 7 or later.
■You are using a Mac and you wish to take
advantage of the extra features that the driver
provides: lower latency performance and loopback
channels (see “Loopback” on page 21).
If neither of the above scenarios apply to you, then
you can skip software installation if you wish, and
proceed to chapter 3, “Hardware Installation”
(page 15).
Download and run the M Series installer
To download the latest M Series installer for Mac
or Windows, visit www.motu.com/m2-start (it’s
the same installer for both the M2 and M4).
Follow the directions that the installer gives you.
☛We recommend that you run the software
installer before you connect your M Series
interface to your computer and power it on.
Industry-leading I/O latency performance
On macOS and Windows, the M series driver
provides exceptionally low I/O latency
performance. For example, with a 32-sample
buffer size, an M Series interface operating at 96
kHz produces round trip latency (RTL)
performance of 2.5 milliseconds (ms) on
Windows and 2.5 ms on macOS. RTL is the
measurement of the time it takes audio to pass
from an analog input, through a DAW host, to an
analog output.

SOFTWARE INSTALLATION
12
M Series Core Audio driver for macOS
On macOS, to enable your M Series interface in
your Core Audio-compatible host software, go to
the menu item or preference in your host audio
software where you choose the audio device (Core
Audio driver) you wish to use, and then select the
M2 or M4 by name.
Figure 2-1: Choosing the M Series ASIO driver in Performer Lite on
Windows (Setup menu > Configure Audio System > Configure
Hardware Driver).
M Series ASIO driver for Windows
On Windows, to enable your M Series interface in
your ASIO host software, choose M Series ASIO
driver.
Figure 2-2: Choosing the M Series ASIO driver in Performer Lite on
Windows (Setup menu > Configure Audio System > Configure
Hardware Driver).
M SERIES CONTROL PANEL (WINDOWS ONLY)
On Windows, you can access the M Series control
panel in the Windows Start menu. In Performer
Lite, you can access it by clicking the Configure
Driver button shown in Figure 2-2.
Figure 2-3: M Series control panel.
Sample Rate (Hz)
Choose the desired sample rate (Figure 2-3) for
operation with your host software. Make sure your
host software matches the sample rate you choose
here.
Buffer Size
The Buffer Size setting (Figure 2-1 and Figure 2-3)
determines the amount of latency (delay) you may
hear when live audio is patched through your host
audio software. Smaller buffer sizes produce lower
latency, with sizes of 256 samples or less producing
virtually imperceptible delay. Many host
applications report audio hardware I/O latency, so
you can see what happens to the reported latency
when making adjustments to this setting.
Be careful with very small buffer sizes, as they can
cause performance issues from your host software
or PC.
☛At sea level, audio travels approximately one
foot (30 cm) per millisecond. A latency of ten
milliseconds is about the same as being ten feet
(three meters) from an audio source.

SOFTWARE INSTALLATION
13
MIDI I/O ON WINDOWS
On Windows, the M Series driver installer
provides a USB MIDI driver for the M2 and M4.
This driver allows you to access the their MIDI
input and output ports through its USB
connection to the computer. The ports are
published in Windows and are available to all
MIDI software.
MIDI I/O SETUP ON THE MAC
Core MIDI is the “under-the-hood” component of
macOS that handles MIDI services for MIDI
hardware and software. Core MIDI provides many
universal MIDI system management features,
including MIDI communication between your M
Series interface and all Core MIDI compatible
software.
Audio MIDI Setup is a utility included with macOS
that allows you to configure your M Series
interface for use with all Core MIDI compatible
applications. Audio MIDI Setup provides:
■A “virtual” studio on your Mac that graphically
represents your MIDI hardware setup and that is
shared by all Core MIDI-compatible programs
■A simple, intuitive list of your MIDI devices
whenever you need it in any Core MIDI-
compatible program
Launching Audio MIDI Setup
1Make sure your M Series interface is connected
(a USB connection is required) and turned on.
2Launch the Audio MIDI Setup utility.
This can usually be found in /Applications/
Utilities. If it has been moved, just search for
Audio MIDI Setup.
3Confirm that the MIDI interface is present in
the MIDI Devices tab (or window) in Audio MIDI
Setup. If the interface does not appear, or if it is
grayed out, check your cable connections and click
Rescan MIDI.
Connecting MIDI devices to the M Series
Once your M Series interface appears in Audio
MIDI Setup, you are ready to add devices, indicate
how they are connected, and identify properties
they may have for particular purposes. This
information is shared with all Core MIDI
compatible applications.
To add a device in Audio MIDI Setup:
1Click Add Device.
2Drag on its input and output arrows to draw
connections to the M Series interface that match
its physical connection.
Figure 2-4: Connecting devices to an M Series interface. In this example,
a controller keyboard is connected to the M4 MIDI IN, and a sound
module is connected to the M4 MIDI OUT.
3Double-click the device to make settings, such
as input and output channels, that further describe
the device.

SOFTWARE INSTALLATION
14
Figure 2-5: Device settings.
4Repeat the above steps for each MIDI device
connected to the interface.
5When you are finished, quit Audio MIDI Setup.
Your configuration is automatically saved as the
default configuration, and it is shared with all
Core MIDI-compatible software.
WORKING WITH HOST AUDIO SOFTWARE
For further information about using your M Series
interface with host audio software, see chapter 4,
“Working with Host Audio Software” (page 19).

CHAPTER
15
3Hardware Installation
A TYPICAL M2 SETUP
Figure 3-1: A typical M2 studio setup.
Mic
or
guitar
Mic
or
guitar
Headphones
MIDIcontroller
or synthesizer
MIDI synth
Mac or PC
DJ system
Speakers

HARDWARE INSTALLATION
16
A TYPICAL M4 SETUP
Figure 3-2: A typical M4 studio setup.
Mic
or
Guitar
Mic
or
Guitar
Headphones
MIDIcontroller
or synthesizer
MIDI synth
Mac or PC
DJ system
A speakers
B speakers MIDIcontroller
or synthesizer

HARDWARE INSTALLATION
17
CONNECTING TO A MAC OR PC
Connect the M2 or M4 to your host computer
with the supplied USB-C to USB-A cable. If your
computer has USB-C ports, use a USB-C to
USB-C cable (rated for USB2) or a USB-A adapter
(both sold separately). The M2 is powered by its
USB connection to the host computer.
CONNECTING TO AN iOS DEVICE
Recent-generation Apple iOS devices have two
types of connectors: Lightning or USB-C.
For iOS devices with a Lightning port, an Apple
Lightning to USB3 Camera Adapter is required:
https://www.apple.com/shop/product/MK0W2A
M/A/lightning-to-usb-3-camera-adapter
Figure 3-3: The Apple Lightning to USB3 Camera Adapter.
Connect USB-C port on this adapter to a wall
outlet for power. (The M2 and M4 cannot be
powered from the iPad itself. They draw too much
power for 48V, the LCD, etc.)
The USB Type A port can then be connected to the
M2 or M4, or a powered USB hub for connection
to many USB devices.
AUDIO CONNECTIONS
Here are a few things to keep in mind as you are
making audio connections to your M Series
interface.
Mic/line/instrument inputs with preamps
Connect a microphone, guitar or line-level analog
input to the XLR/quarter-inch combo jacks with
either a standard mic cable or a balanced cable
with a quarter-inch plug.
☛Do not connect a +4 (line level) XLR cable to
the inputs (because of the preamps). Use a
quarter-inch input instead.
Phantom power
If you are connecting a condenser microphone or
another device that requires phantom power,
engage the corresponding 48V phantom power
switch.
Preamp gain
The M series preamps provides 60 dB of gain. Use
the front panel trim knobs to adjust gain as needed
for each input. Watch the input level meter in the
LCD while adjusting gain. Try to adjust gain as
high as possible without clipping, which is
indicated by the red rectangle at the top of the
meter.
Combo jack summary
Use these guidelines for 48V phantom power and
trim settings on the two combo input jacks:
AC power
USB power
adapter
M2, M4 or
powered USB hub
Input 48V Trim
Condenser mic On As needed
Dynamic mic Off As needed
Guitar Off As needed
Line level Off Zero

HARDWARE INSTALLATION
18
TRS quarter-inch analog inputs and outputs
Quarter-inch analog inputs and outputs are
balanced (TRS) connectors that can also accept an
unbalanced plug. The outputs are DC-coupled, so
they can be used for CV control output.
☛Quarter-inch analog outputs are not
cross-coupled. Therefore, when connecting them
to an unbalanced input, use a TRS plug with the
ring disconnected. Not floating the negative
terminal will short it to the sleeve ground and
cause distortion.
Unbalanced RCA outputs
Connect the unbalanced RCA outputs to other
gear that has similar unbalanced RCA inputs, such
as DJ systems, karaoke equipment or consumer
audio devices.
Monitor outs
In a standard studio configuration, the monitor
outs are intended for a pair of primary studio
monitors, but they can be used as regular outputs
for any purpose.
MIDI CONNECTIONS
Connect your MIDI device’s MIDI IN jack to the
M series MIDI OUT jack (Connection A below).
Conversely, connect the MIDI device’s MIDI OUT
jack to the M Series MIDI IN jack (Connection B).
Figure 3-4: Connecting a MIDI device to an M Series interface.
One-way MIDI connections
MIDI devices that do not receive MIDI data, such
as a dedicated keyboard controller, guitar
controller, or drum pad, only need Connection B
shown in Figure 3-4. Similarly, devices that never
send data, such as a sound module, only need
Connection A. Make both connections for any
device that needs to both send and receive MIDI
data.
Connecting additional gear with MIDI THRUs
If you need to connect several pieces of MIDI gear,
run a MIDI cable from the MIDI THRU of a
device already connected to the M Series interface
to the MIDI IN on the additional device as shown
below in Figure 3-5. The two devices then share
the M Series MIDI OUT port. This means that
they share the same set of 16 MIDI channels, too,
so try to do this with devices that listen to only one
MIDI channel (such as effects modules), which
makes it easier to avoid MIDI channel conflicts.
Figure 3-5: Connecting additional devices with MIDI THRU ports.
M Series
rear panel
MIDI Device
MIDI
cables
MIDI
IN MIDI OUT
MIDI
OUT MIDI IN
Connection A
Connection B
MIDI IN
MIDI
cable
MIDI Device
MIDI
IN
MIDI
THRU
MIDI
OUT
M Series
rear panel

CHAPTER
19
4Working with Host Audio Software
OVERVIEW
M Series interfaces provide multi-channel audio
input and output for Core Audio compatible audio
applications on the Mac and ASIO compatible
applications on Windows, including MOTU’s
Performer Lite and Digital Performer, Apple’s
Logic Pro and GarageBand, and other third-party
software applications such as Ableton Live, Avid
Pro Tools, Cockos Reaper, Propellerhead Reason,
Steinberg Cubase and Nuendo, Cakewalk
SONAR, PreSonus Studio One, Bitwig, and others.
Performer Lite and Ableton Live Lite are both
available as a free download for M Series owners at
motu.com. Just log in to your account and go to
your Product Registrations tab. For complete
information about all of Performer Lite’s powerful
workstation features, refer to the Performer Lite
User Guide.pdf found in the Help menu of the
Performer Lite application.
Digital Performer, MOTU’s state-of-the-art digital
audio workstation software, is available separately;
for details about upgrading from Performer Lite to
Digital Performer, talk to your authorized MOTU
dealer or visit motu.com.
Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Choosing the M Series driver. . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Reducing monitoring latency. . . . . . . . . . . . . . . . . . . . . . . . . . .20
Loopback. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
PREPARATION
Install your host audio software first if you haven’t
already done so, and complete these chapters
before proceeding:
■chapter 2, “Software Installation” (page 11)
■chapter 3, “Hardware Installation” (page 15)
CHOOSING THE M SERIES DRIVER
For macOS audio software
For macOS, go to the Sound control panel and
choose the M2 or M4 for input and output. If
you’ve installed the M series driver for macOS, go
to the menu item or preference in your host audio
software where you choose the audio device (Core
Audio driver) you wish to use, and then select the
M2 or M4 by name (see Figure 2-1 on page 12).
For Windows audio software
For audio software running under Windows, go to
the menu item or preference where you choose the
ASIO driver you wish to use, and then choose
MOTU M Series.
Figure 4-1: Choosing the M Series ASIO driver in Performer Lite on
Windows (Setup menu > Configure Audio System > Configure
Hardware Driver).

WORKING WITH HOST AUDIO SOFTWARE
20
Where to go in popular audio hosts
Here is the location for this setting in various
popular audio software host applications:
Other audio software
Consult your software’s manual for further
information.
REDUCING MONITORING LATENCY
Monitoring latency is a slight delay caused by
running an input signal through your host audio
software and back out. For example, you might
hear it when you drive a live guitar input signal
through an amp modeling plug-in running in
your audio sequencer.
This delay is caused by the amount of time it takes
for audio to make the entire round trip through
your computer, from when it first enters an input
on the M Series interface, passes through the
interface hardware into the computer, through
your host audio software, and then back out to an
output.
Monitoring through the M2 or M4
If you don’t need to process a live input with
plug-ins, the easiest way to avoid monitoring
latency is to disable your DAW’s live monitoring
feature and instead engage the MON (monitor)
switch on the front panel of your M Series
interface. Visit motu.com/m2-start (or /m4-start)
to watch a video about this feature.
Monitoring through your host audio software
If you do need to process a live input with host
software plug-ins, or if you are playing virtual
instruments live through your MOTU audio
hardware, you can significantly reduce latency by
adjusting the audio buffer setting in your host
audio software, as explained in the next section.
☛It is important to note that monitoring delay
has no effect on the recording, or playback, of
audio data from disk. The actual recording and
playback is extremely precise, it is only the
monitoring of your live input signal which may be
delayed.
Adjusting your host software audio buffer
Buffers are small bundles of audio data. Your M
Series interface “speaks” to your computer in
buffers, rather than one sample at a time. The size
of these buffers determine how much delay you
hear when monitoring live inputs through your
audio software: larger buffers produce more delay;
smaller buffers produce less.
Adjusting buffer size on macOS
Under macOS, audio I/O buffer size is handled by
the host audio application (not by the M Series
Core Audio driver). Most audio software
applications provide an adjustable audio buffer
setting that lets you control the amount of delay
you’ll hear when monitoring live inputs or
processing them with software plug-ins, as shown
for Performer Lite in Figure 4-2.
Host software Location for choosing the M2 or M4
Digital Performer
and Performer Lite
Setup menu > Configure Audio System >
Configure Hardware Driver
Pro Tools 9 or later Setup menu > Playback Engine or Current
Engine
Logic Pro Preferences > Audio tab > Devices tab > Core
Audio tab
Garage Band Garage Band menu > Preferences > Audio/
MIDI > Audio Output/Input menus
Cubase and Nuendo Device Setup > Devices list > VST Audio
System menu
Live Preferences > Audio tab
Reason Preferences > Audio preferences
Reaper Preferences > Audio prefs > Devices