MOTU Audio Express User manual

™
Audio Express
User Guide for Mac
1280 Massachusetts Avenue
Cambridge, MA 02138
Business voice: [phone]
Business fax: [phone]
Web site: www.motu.com
Tech support: www.motu.com/support
!Audio Express Manual/Mac Page 1 Tuesday, February 22, 2011 11:10 AM

About the Mark of the Unicorn License Agreement and
Limited Warranty on Software
TO PERSONS WHO 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,
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documentation are limited to the terms and conditions described in the license
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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 enclosed program on a single computer; (b) physically transfer
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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
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product, then MOTU shall have no responsibility to replace the disk(s) under this
Limited Warranty.
THIS LIMITED WARRANTY AND RIGHT OF REPLACEMENT IS IN LIEU OF,
AND YOU HEREBY WAIVE, ANY AND ALL OTHER WARRANTIES, BOTH
EXPRESS AND IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.THE
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LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING
BUT NOT LIMITED TO LOSS OF USE, LOSS OF PROFITS, LOSS OF DATA OR
DATA BEING RENDERED INACCURATE, OR LOSSES SUSTAINED BY THIRD
PARTIES EVEN IF MOTU HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS
WHICH MAY VARY FROM STATE TO STATE. SOME STATES DO NOT ALLOW
THE LIMITATION OR EXCLUSION OF LIABILITY FOR CONSEQUENTIAL
DAMAGES, SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU.
Update Policy
In order to be eligible to obtain updates of the program, you must complete and return
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Copyright Notice
Copyright © 2011 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.
Limited Warranty on Hardware
Mark of the Unicorn, Inc. and S&S Research (“MOTU/S&S”) warrant this equipment
against defects in materials and workmanship for a period of TWO (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 Mark of the Unicorn 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 Mark of the Unicorn, Inc., 1280
Massachusetts Avenue, MA 02138.You must use the product’s original packing
material for in shipment, and insure the shipment for the value 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.
ALL IMPLIED WARRANTIES, INCLUDING IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
LIMITED IN DURATION TO TWO (2) YEARS FROM THE DATE OF THE
ORIGINAL RETAIL PURCHASE OF THIS PRODUCT.
THE WARRANTY AND REMEDIES SET FORTH ABOVE ARE EXCLUSIVE
AND IN LIEU OF ALL OTHERS, ORAL OR WRITTEN, EXPRESS OR IMPLIED.
No MOTU/S&S dealer, agent, or employee is authorized to make any modification,
extension, or addition to this warranty.
MOTU/S&S ARE NOT RESPONSIBLE FOR SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES RESULTING FROM ANY BREACH OF
WARRANTY, OR UNDER ANY LEGAL THEORY, INCLUDING LOST PROFITS,
DOWNTIME, GOODWILL, DAMAGE OR REPLACEMENT OF EQUIPMENT
AND PROPERTY AND COST OF RECOVERING REPROGRAMMING, OR
REPRODUCING ANY PROGRAM OR DATA STORED IN OR USED WITH
MOTU/S&S 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
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rights which vary from state to state.
MOTU, Digital Performer, AudioDesk, Mark of the Unicorn and the unicorn silhouette
logo are registered trademarks of Mark of the Unicorn, Inc.
This equipment has been type tested and found to comply with the limits for a class B digital device,
pursuant to Part 15 of the FCC Rules.These limits are designed to provide reasonable protection
against harmful interference in a residential installation.This equipment generates, uses, and can
radiate radio frequency energy and, if not installed and used in accordance with the instruction manual,
may cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause interference to radio
or television equipment reception, which can be determined by turning the equipment off and on, the
user is encouraged to try to correct the interference by any combination of the following measures:
• Relocate or reorient the receiving antenna
• Increase the separation between the equipment and the receiver
• Plug the equipment into an outlet on a circuit different from that to which the receiver is connected
If necessary, you can consult a dealer or experienced radio/television technician for additional
assistance.
PLEASE NOTE: only equipment certified to comply with Class B (computer input/output devices,
terminals, printers, etc.) should be attached to this equipment, and it must have shielded interface
cables in order to comply with the Class B FCC limits on RF emissions.
WARNING: changes or modifications to this unit not expressly approved by the party
responsible for compliance could void the user's authority to operate the equipment.
!Audio Express Manual/Mac Page 2 Tuesday, February 22, 2011 11:10 AM

III
Contents
5
Quick Reference: Audio Express Front Panel
6
Quick Reference: Audio Express Rear Panel
7
Quick Reference: MOTU Audio Setup
9
About the Audio Express
13
Packing List and Mac System Requirements
15
Installing the Audio Express Hardware
25
Installing the Audio Express Mac Software
29
MOTU Audio Setup
33 Audio Express Front Panel Operation
37
Digital Performer
41
AudioDesk
45
Other Mac OS X Software
51
Reducing Monitoring Latency
57
CueMix FX
81
MOTU SMPTE Console
85 Troubleshooting
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IV
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Quick Reference: Audio Express Front Panel
1. These two Precision Digital Trim™ rotary encoders
provide triple-function control over the trim level,mix volume,and pan of the XLR/TRS combo jacks on the rear panel.Push the MIX knob (4) repeatedly to cycle among the four separate mixes and trim mode.The LEDs (12) indicate the current mix,or trim mode.When a mix is active,push and hold the MIX knob to toggle between volume and pan control, as indicated by the LEDs (12). When in trim mode,use the knob and input level meters (9) to calibrate the input signal level.These knobs provide +60 dB and +22 dB of boost, respectively, for the mic (XLR) and instrument (TRS) input jacks.Adjust- ment can be made in approximately 1 dB increments. Both jacks have preamps, so you can plug in just about anything:a microphone,a guitar or even a synth.For +4 dB signals,use the TRS line inputs instead.For the Mic (XLR) input,push the encoder to toggle a -20 dB pad; push and hold to toggle 48V phantom power. When in mix mode,use the knob to control the jack’s input volume or pan (as indicated by the LEDs,12) for the currently selected mix.
2. These two Precision Digital Trim™ rotary encoders
provide triple-function control over the trim level,mix volume,and pan of the TRS line in 3-4 jacks on the rear panel.Push the MIX knob (4) repeatedly to cycle among the four separate mixes and trim mode.The LEDs (12) indicate the current mix,or trim mode.When a mix is active,push and hold the MIX knob (4) to toggle between volume and pan control,as indicated by the LEDs (12). In trim mode,these knobs provide 22 dB of gain in approximately 1 dB increments.
3. This rotary encoder controls the input volume and pan of
the S/PDIF jack for the currently selected mix.In trim mode,this knob provides 22 dB of gain in approximately 1 dB increments.
4. This multi-function knob controls volume of the Audio
Express’s four mix busses (12).Push the knob repeatedly to cycle among the four mix busses,as indicated by the LEDs (12).When a mix is active,push and hold the VOL knob to toggle the individual channel knobs (1,2 and 3) between volume and pan control,as indicated by the LEDs (12).
5. Turn the PHONES knob to control the headphone jack
volume.Push the knob to also control the Audio Express’s main outs,as indicated by the“+main”LED (6).Push again to control
only
the main outs (instead of phones);
in this case,the “+main”LED flashes. When power is off, push the PHONES knob to power on the Audio Express;push and hold to turn it off.When connected to the computer via FireWire, the Audio Express is powered by its FireWire connection.When connected via USB,it must be powered with the included DC power adapter.
6. The“+main”LED has three states:off,on,and flashing.
Push the PHONES knob to cycle among three volume control modes:phone jack only (off),phones+main outs (on),or main outs only (flashing).
7. These LEDs indicate whether the -20 dB pad or 48V
phantom power is enabled or disabled for the corre- sponding mic input (1).
8. The MAIN OUT meters provide five-segment stereo
metering for the main outs,ranging from -42 dB to -1 dB.The LINE meters provide four-segment metering for the line inputs 3-4 and signal activity LEDs at the bottom for line outs 3-4.
9. The MIC / INST meters provide ten-segment ladder LED
metering for the two mic/instrument combo jacks, ranging from -42 dB to clip.
10. Indicates the current operational sample rate. 11. The MIDI and S/PDIF activity LEDs indicate signal
presence for each input and output.
12. The Mix LEDs indicate what is being controlled by the
mix/trim knobs (1,2, 3 and 4).Push the MIX knob (4) repeatedly to cycle among the four separate mixes and trim mode.When a mix is active,the knobs control input levels for the current mix.Push and hold the MIX knob (4) to toggle between volume and pan control.When trim mode is selected,the knobs control input trim levels.
13. This is a standard quarter-inch stereo headphone jack.
From the factory,its output matches the main outs on the rear panel.But it can be programmed to mirror any other output pair (digital or analog).It can even be programmed to serve as its own independent output. See “Phones Assign”on page 32.Use the volume knob above to control its level.
31
11
2 4 5 6 7 8 9 10
1213
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1. Connect a MIDI device here using standard MIDI cables.
Connect the Audio Express’s MIDI OUT port to the MIDI IN port on the other device.Conversely,connect the Audio Express’s MIDI IN port to the MIDI OUT port on the other device.You can connect different devices to each port, such as a controller device to the IN port and a sound module to the OUT port.You can also daisy-chain MIDI devices,but be sure to manage their MIDI channels (so that they don’t receive or transmit on the same channel).
2. These jacks provide stereo, 24-bit S/PDIF digital input
and output at any sample rate up to 96kHz.
3. This jack accepts any standard 9-18V DC power supply
with either tip-positive or tip-negative polarity.
4. These two balanced,quarter-inch jacks serve as the
Audio Express’s main outputs.You can connect them to a set of powered studio monitors and then control the volume from the front panel volume knob.To hear disk tracks in your audio software on these main outs,assign
the disk tracks (and master fader) to these main outs (
Main Out 1-2
).You can also use the Audio Express’s on-
board CueMix mixing to monitor live Audio Express inputs here as well.
5. The Audio Express’s analog line outputs are gold-plated,
balanced +4dBTRS (tip/ring/sleeve) quarter-inch connectors that can also accept an unbalanced plug. They are equipped with 24-bit, 128x oversampling converters.
6. These XLR/TRS combo jacks accept either a mic cable or a
cable with a quarter-inch plug.Use the front panel mic 1-2 encoders to apply up to +60 dB or +22 dB of boost, respectively,for the mic (XLR) or instrument (TRS) input. To toggle the -20 dB pad for the XLR (mic) input,push the corresponding front-panel mic encoder.To toggle 48V phantom power for the XLR (mic) input,push and hold the corresponding front-panel encoder.
7. Equipped with 24-bit 96 kHz converters,these two
analog inputs are gold-plated, balanced TRS (tip/ring/ sleeve) quarter-inch connectors that can also accept an unbalanced plug.They do not have microphone preamps,so they are best used for synthesizers,drum machines,effects processors,and other instruments with line level signals (either -10 dB or +4 dB).These inputs are also equipped with the Audio Express’s Preci- sion Digital Trim™ feature:digitally controlled analog trims that let you adjust input level in approximately 1 dB increments from either front panel or the included CueMix FX software.The trim can be adjusted over a range of 22 dB.
8. Connect a standard foot switch here for hands-free
punch-in and punch-out during recording.For details about how to set this up,see “Enable Pedal”on page 32.
9. Connect the Audio Express to the computer here via
either FireWire or USB2,using either the standard 1394 FireWire A or USB cable provided with your Audio Express.There’s not much difference, except that FireWire offers bus-powered operation (without the DC power supply).
Important note: it is best to turn off
the Audio Express when plugging in the FireWire cable,as this avoids the possibility of static discharge,which can harm the electrical compo- nents in the Audio Express or your computer
.
Quick Reference: Audio Express Rear Panel
1 2 4
8 7
3 5 6
9
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CHAPTER
7
Quick Reference: MOTU Audio Setup
If you have a foot switch connected to
the Audio Express, these settings let
you map the foot switch to any
computer keyboard key for both the up
and down position.For details about
how to set this up,see “Enable Pedal”
on page 32.
This menu lets you choose what you will hear
from the headphone jack.To mirror the main
outs,choose Main Out 1-2.Or you can mirror
any other output pair.To hear the phones as
their own independent output,choose
Phones 1-2.
Determines the clock source for your Audio
Express.If you’re just using the analog ins
and outs,set this to Internal.The other
settings are for digital transfers via
S/PDIF or synchronization to time code or
other audio devices.
Choose the sample rate for the
Audio Express here.
Click the tabs to access general
MOTU interface settings or
settings specific to the Audio
Express (or other connected
interface).
In the standard Mac OS X fashion,the
setup software appears in the dock
when you launch it.If the Launch MOTU
Audio Setup when hardware becomes
available option is checked (as shown
above),the icon appears as soon as you
switch on your Audio Express interface.
If you right-click or control-click the
dock icon,a menu of hardware settings
appears as shown to the right.You can
view and configure any hardware
settings from this menu, without
opening the setup software window.
Click the General tab to access these settings.
Specifies the stereo input and
output pair when the Audio
Express is chosen for Mac OS X
audio I/O.
Check this option if you would like the MOTU
Audio Setup application to open as soon as a
MOTU interface is detected (switched on,
plugged in,etc.)
This button opens another dialog
that lets you assign your own
customized names to each Audio
Express input and output.For
example,if you have a lead vocal
mic plugged into input 1,you
could name it“LeadVox”.Your
customized names then appear in
your host audio application (if it
supports CoreAudio input
naming).
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8
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CHAPTER
9
1
About the Audio Express
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
The Audio Express Rear Panel. . . . . . . . . . . . . . . . . . . . . . . . 10
The Audio Express Front Panel. . . . . . . . . . . . . . . . . . . . . . . 11
16-bit and 24-bit recording . . . . . . . . . . . . . . . . . . . . . . . . . . 12
CueMix mixing and effects. . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AudioDesk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Digital Performer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Other Host Audio Software . . . . . . . . . . . . . . . . . . . . . . . . . . 12
OVERVIEW
The Audio Express is a hybrid FireWire and USB2
audio interface for Mac andWindows that offers six
independent inputs and six independent outputs.
Both analog and digital I/O are offered at sample
rates up to 96 kHz.All inputs and outputs can be
accessed simultaneously. The Audio Express is
housed in a sturdy, compact half-rack enclosure
that connects directly to a computer via a standard
FireWire or USB cable.
The Audio Express offers the following main
features:
■ Universal computer connectivity via FireWire or
high-speed USB 2.0
■ Bus-powered operation (FireWire only)
■ Two 24-bit analog quarter-inch (TRS) inputs
■ Four 24-bit analog quarter-inch (TRS) outputs
■ Two combo XLR/TRS mic/guitar inputs with
preamps, 48V phantom power, 20 dB pad, and
Precision Digital Trim™ preamp gain adjustment
■ Operation on all I/O at standard sample rates up
to 96 kHz
■ Digitally controlled analog trim for all analog
inputs
■
Coaxial S/PDIF digital I/O at sample rates up to
96 kHz
■ MIDI I/O
■
Foot switch for hands-free punch-in/out
■
On-board SMPTE synchronization
■ Headphone jack with independent output and
volume control
■ Front panel volume control of the Main Outs
■ Front-panel mixing of live inputs
■ Front panel metering and status LEDs
■ Stand-alone operation
■ Mac and Windows drivers for multi-channel
operation and across-the-board compatibility with
any audio software on current Mac and Windows
systems
■ CueMix FX cross-platform mixing software with
attractive graphic mixing and a convenient tabbed
interface for quick access to all features in one
window. CueMix also provides a full-screen real-
time FFT display, spectrogram “waterfall” display,
oscilloscope, X-Y plot, linear or polar phase
analysis, and a tuner.
■ AudioDesk™, full-featured audio workstation
software for Mac OS X that supports both 16-bit
and 24-bit recording
With a variety of I/O formats, mic preamps and
no-latency mixing and processing of live input, the
Audio Express is a complete, portable“studio in a
box” when used with a Mac or Windows computer.
!Audio Express Manual/Mac Page 9 Tuesday, February 22, 2011 11:10 AM

ABOUT THE AUDIO EXPRESS
10
THE AUDIO EXPRESS REAR PANEL
The rear panel has the following connectors:
■
Four gold-plated, balanced +4dB quarter-inch
(TRS) analog outputs (with 24-bit 96 kHz
converters)
■ Two gold-plated, balanced quarter-inch (TRS)
analog inputs (with 24-bit 96 kHz converters)
■
Two combo XLR/TRS mic/instrument inputs
■ Coaxial S/PDIF in/out
■
MIDI IN and MIDI OUT connectors
■ 1394 FireWire A connector
■ High-speed USB 2.0 connector
■ Foot pedal input
■ DC power jack
6 inputs and 6 outputs
All Audio Express inputs and outputs can be used
simultaneously, for a total of 6 inputs and 6
outputs:
All inputs and outputs are discrete and can be
active simultaneously.
The headphone outputs can operate as an
independent output pair, or they can mirror any
other Audio Express output pair, such as the main
outs.
Mic/guitar inputs with preamps
The two mic/instrument inputs are equipped with
preamps and“combo” XLR/TRS jacks, which
accept XLR microphone inputs or quarter-inch
guitar/instruments inputs. Individual 48 volt
phantom power and a 20 dB pad can be supplied
independently to each mic input. The Precision
Digital Trim™ knobs on the front panel for each
mic/instrument input provide 60 dB of boost for
the XLR mic input and 22 dB of boost for the TRS
instrument input in approximately 1 dB
increments.
Analog
The quarter-inch analog inputs are equipped with
24-bit 96 kHz A/D converters. The analog outputs
have 24-bit 96 kHz D/A converters.All audio is
carried to the computer in a 24-bit data stream.
All quarter-inch analog outputs and inputs are on
balanced TRS +4dB jacks.All of these jacks can
also accept unbalanced plugs.
Precision Digital Trim™
All of the Audio Express’s analog inputs are
equipped with digitally controlled analog trims
that allow adjustments in approximately 1 dB
increments. The mic/guitar input trims can be
adjusted using front-panel digital rotary encoders
with 60 dB of adjustment for the mic input and 22
dB for the TRS input. All analog inputs, including
the rear-panel TRS analog inputs, can be trimmed
using the Audio Express’s included CueMix FX
control software for Mac andWindows.This allows
you to fine-tune trim settings for synths, effects
modules and a wide variety of analog inputs for
optimum levels. Different trim configurations can
then be saved as files on disk for instant recall.
S/PDIF
The Audio Express rear panel provides coaxial
S/PDIF input and output.
MIDI I/O
The Audio Express’s standard MIDI IN and MIDI
OUT jacks supply 16 channels of MIDI I/O to and
from the computer via the Audio Express’s
Connection Input Output
Analog 24-bit 96 kHz on bal/unbal TRS 2 4
Mic preamps 24-bit 96 kHz on XLR/TRS combo 2 -
SPDIF 24-bit 96kHz digital 2 2
Total 6 6
!Audio Express Manual/Mac Page 10 Tuesday, February 22, 2011 11:10 AM

ABOUT THE AUDIO EXPRESS
11
FireWire or USB connection. Timing accuracy can
be sample-accurate with host software that
supports it.
Pedal input
The quarter-inch foot pedal jack accepts a standard
foot switch. When you push the foot switch, the
Audio Express triggers a programmable keystroke
on the computer keyboard. For example, with
MOTU’s Digital Performer audio sequencer
software, the foot switch triggers the 3 key on the
numeric keypad, which toggles recording in
Digital Performer. Therefore, pressing the foot
switch is the same as pressing the 3 key. The Audio
Express Control Panel software lets you program
any keystroke you wish.
On-board SMPTE synchronization
The Audio Express can resolve directly to SMPTE
time code via any analog input, without a separate
synchronizer. It can also generate time code via any
analog output. The Audio Express provides a
DSP-driven phase-lock engine with sophisticated
filtering that provides fast lockup times and sub-
frame accuracy.
The included MOTU SMPTE Console™ software
provides a complete set of tools for generating and
regenerating SMPTE time code, which allows you
to slave other devices to the computer. Like
CueMix FX, the synchronization features are
cross-platform and compatible with any audio
software that supports them.
Hybrid FireWire/USB2 connectivity
FireWire has long been recognized as a reliable,
high-performance connectivity standard for
professional MOTU audio interfaces. Meanwhile,
high-speed USB2 has also developed into a widely
adopted standard for connecting peripheral
devices to personal computers.
To fully support both formats, your Audio Express
Hybrid audio interface is equipped with both a
FireWire A (400 Mbit/sec) connector and a hi-
speed USB2 (480 Mbit/sec) connector,and you can
use either port to connect the Audio Express to
your computer. This gives you maximum flexibility
and compatibility with today’s ever-expanding
universe of Mac and Windows computers.
The Audio Express has the ability to power itself
from its FireWire connection to the computer, for
convenient, mobile bus-powered operation.
Power supply
If you do not want the Audio Express to draw
power from the computer, and AC power is
available, you can power the Audio Express from
any standard 9-18V, 5 watt DC power supply with
any polarity (tip positive or negative).
THE AUDIO EXPRESS FRONT PANEL
Front-panel mixing
The six digital rotary encoders on the Audio
Express front panel provide hands-on mixing of all
live inputs.In fact,these controls provide control of
up to four separate mixes. Use the MIC, LINE and
S/PDIF knobs to control input volume for each
mix; push the MIX knob to cycle among the four
different mixes, plus trim mode, which lets you
adjust input trim for each across all mixes.
48V phantom power and pad
The two MIC knobs let you toggle independent
48V phantom power and -20 dB pad settings for
the two mic inputs. See “Mic/guitar inputs with
preamps” on page 10.
Headphone output and main volume control
The Audio Express front panel provides a quarter-
inch stereo headphone output jack and volume
knob, which can be configured to control phones
volume, phones and main outs together, or the
main outs by themselves.
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ABOUT THE AUDIO EXPRESS
12
Status and metering LEDs
The LED section provides visual indication of
audio levels, audio activity status, and the current
settings for all front-panel controls.
16-BIT AND 24-BIT RECORDING
The Audio Express system handles all data with a
24-bit signal path,regardless of the I/O format.You
can record and play back 16-bit or 24-bit audio files
at any supported sample rate via any of the Audio
Express’s analog or digital inputs and outputs. 24-
bit audio files can be recorded with any compatible
host application that supports 24-bit recording.
CUEMIX MIXING AND EFFECTS
All Audio Express inputs and outputs can be
routed to the on-board CueMix 8-bus (4 stereo)
digital mixer driven by hardware-based DSP. The
mixer allows you to mix all inputs to any output
pair directly in the Audio Express hardware,
independent of the computer. The on-board mixer
can be used when the Audio Express is operating
stand-alone (without a computer) as a complete
portable mixer.
AUDIODESK
AudioDesk is a full-featured, 24-bit audio
workstation software package included with the
Audio Express system (for Mac only). AudioDesk
provides multi-channel waveform editing,
automated virtual mixing, graphic editing of ramp
automation, real-time effects plug-ins with 32-bit
floating point processing, crossfades, support for
many third-party audio plug-ins, background
processing of file-based operations, sample-
accurate editing and placement of audio, and more.
DIGITAL PERFORMER
The Audio Express system is fully integrated with
MOTU’s award-winning Digital Performer audio
sequencer software package.
OTHER HOST AUDIO SOFTWARE
The Audio Express system includes a standard
Mac OS X Core Audio driver for multichannel I/O
with any audio application that supports Core
Audio.
!Audio Express Manual/Mac Page 12 Tuesday, February 22, 2011 11:10 AM

CHAPTER
13
2
Packing List and Mac System
Requirements
PACKING LIST
The Audio Express ships with the items listed
below. If any of these items are not present in your
Audio Express box when you first open it, please
immediately contact your dealer or MOTU.
■ One Audio Express I/O rack unit
■
One 6-pin to 6-pin IEEE 1394 “FireWire” cable
■ One USB cable
■ One set of removable rack ears
■ One Audio Express Mac/Windows manual
■ One cross-platform CD-ROM
■ Product registration card
MAC SYSTEM REQUIREMENTS
The Audio Express system requires the following
Mac system:
■ PowerPC G4 CPU 1GHz or faster (including
PowerPC G5 CPUs and all Intel processor Macs)
■ 1 GB of RAM; 2 GB or more is recommended
■ Available FireWire or USB 2.0 port
■ A large hard drive (preferably at least 250 GB)
■ Mac OS X version 10.5 or 10.6; v10.5.8 or later
required
PLEASE REGISTER TODAY!
Please register your Audio Express today.There are
two ways to register.
■
Visit www.motu.com/registration to register on
line
OR
■ Fill out and mail the included product
registration card
As a registered user, you will be eligible to receive
technical support and announcements about
product enhancements as soon as they become
available. Only registered users receive these
special update notices, so please register today!
Be sure to do the same for the included AudioDesk
software, which must be registered separately.You
can do so online. Please be sure to register
AudioDesk as well, so that you will be eligible to
receive online technical support email and
announcements about AudioDesk software
enhancements as soon as they become available.
Thank you for taking the time to register your new
MOTU products!
!Audio Express Manual/Mac Page 13 Tuesday, February 22, 2011 11:10 AM

PACKING LIST AND MAC SYSTEM REQUIREMENTS
14
!Audio Express Manual/Mac Page 14 Tuesday, February 22, 2011 11:10 AM

CHAPTER
15
3
Installing the Audio Express
Hardware
OVERVIEW
Here’s an overview for installing the Audio Express:
Important note before you begin! . . . . . . . . . . . . . . . . . . . 15
Take these precautions to prevent damage to your
computer, the Audio Express and other equipment.
Connect the Audio Express interface . . . . . . . . . . . . . . . . 16
Connect the Audio Express to the computer.
Connect audio inputs and outputs . . . . . . . . . . . . . . . . . . 18
Make analog and digital connections as desired.
Connect MIDI gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Connect a controller, synth or control surface.
Connect and sync S/PDIF devices . . . . . . . . . . . . . . . . . . . . 20
Connect a DAT deck, effects processor or other
device with digital I/O, but be sure to make the
correct clock source settings.
Power options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Choose from among several convenient options.
A typical Audio Express setup . . . . . . . . . . . . . . . . . . . . . . . 22
An example setup for computer-based mixing/FX.
Connect multiple MOTU interfaces . . . . . . . . . . . . . . . . . . 23
Connect additional Audio Express or other audio
interfaces.
IMPORTANT NOTE BEFORE YOU BEGIN!
Before you begin installing the Audio Express (or
any bus-powered device), take these important
precautionary measures to avoid damaging the
sensitive electrical components in your computer,
the Audio Express or other devices being
connected:
■
Tur n off t he computer.
■
Turn off the Audio Express (push and hold the
phones volume knob).
■
Turn off the power of any other devices.
■
Touch the metal casing of the Audio Express to
discharge any static electricity that you may be
carrying just before the installation.
After you have made all of the necessary
connections, as described in this chapter, turn on
the devices in this sequence:
1. Turn on the computer.
2. Turn on the Audio Express.
3. Turn on other devices connected to the Audio
Express.

INSTALLING THE AUDIO EXPRESS HARDWARE
16
CONNECT THE AUDIO EXPRESS INTERFACE
Your Audio Express audio interface is equipped
with both a FireWire A (400 Mbit/sec) connector
and a hi-speed USB2 (480 Mbit/sec) connector,
and you can use either port to connect the Audio
Express to your computer. This gives you
maximum flexibility and compatibility with
today’s ever-expanding universe of Mac and
Windows computers.
Which should I use: FireWire or USB2?
If your computer does not have a FireWire port,
then obviously you will need to connect the Audio
Express to one of its high-speed USB 2.0 ports.
If your computer has both FireWire and USB2,
then it is your choice, and your decision may
depend mostly on other peripherals you may also
have, or bus power, as explained below.
Bus-powered operation requires FireWire
There is only one significant difference between
FireWire and USB2 operation: bus power. FireWire
provides enough power on the FireWire bus that
the Audio Express can be powered solely by its
FireWire connection to the computer. For
complete information, see “Bus power
requirements” on page 20.
If you use USB2, you must also use the DC power
supply included with your Audio Express, as USB2
does not supply enough power by itself.
If you are connecting via FireWire
1 Before you begin, make sure your computer and
the Audio Express are switched off.
2 Plug one end of the Audio Express FireWire
cable (included) into the FireWire socket on the
computer as shown below in Figure 3-1.
☛
You can connect the Audio Express to an
800Mbit“FireWire B” port using a 9-pin to 6-pin
FireWire B cable (not shown). However, the Audio
Express will still operate at its specified 400Mbit
(FireWire A) data rate.
3 Plug the other end of the FireWire cable into the
Audio Express I/O as shown below in Figure 3-1.
Figure 3-1:Connecting the Audio Express to the computer via
FireWire.
☛
Make absolutely sure to align the flat side of
the FireWire plug properly with the flat side of the
FireWire socket on the Audio Express. If you
attempt to force the plug into the socket the wrong
way, you can damage the Audio Express.

INSTALLING THE AUDIO EXPRESS HARDWARE
17
High Speed USB 2.0 versus USB 1.1
There are primarily two types of USB host
controllers widely available on current personal
computers. USB 1.1 controllers support simple
peripherals that don’t require a high speed
connection, such as a computer keyboard, a
mouse, or a printer. USB 2.0 controllers support
high speed devices such as the Audio Express.
Since the Audio Express requires a high speed
connection,it must be connected to a USB 2.0 host
controller or hub.
For the most reliable connection, it is
recommended that you connect the Audio Express
directly to one of your computer’s USB 2.0-
compatible ports. However, since USB 2.0 hubs are
compatible with both types of devices, the Audio
Express can be connected to a USB 2.0 hub along
with USB 1.1 devices if necessary. The Audio
Express will not operate properly if it is connected
to a USB 1.1 hub.
Follow these instructions to determine whether
your computer supports USB 1.1 or USB 2.0:
1 In the Apple menu, choose About this Mac.
2 Click the More Info button to open System
Profiler.
3 In the Contents pane, select USB.
4 Look at the devices in the USB Device Tree.A
device named
USB High-Speed Bus represents a
USB 2.0 root hub. A device named
USB Bus
represents a USB 1.1 root hub.
If you are connecting via high-speed USB 2.0
1 Before you begin, make sure your computer and
the Audio Express are switched off.
2 Plug the flat “type A”plug of the Audio Express
USB cable (included) into a USB2-equipped socket
on the computer as shown below in Figure 3-1.
3 Plug the squared “type B”plug of the USB cable
into the Audio Express I/O as shown below in
Figure 3-1.
Figure 3-2: Connecting the Audio Express to the computer via USB.
Switching Between FireWire and USB
Most of the time, the Audio Express can detect
whether a FireWire or a USB cable is connected to
it, and it will automatically switch to FireWire
operation or USB operation accordingly. Some
FireWire or USB ports that do not provide bus
power can not be automatically detected by the
Audio Express, and you may need to switch the
device to FireWire mode or USB mode manually:
When the Audio Express switches to FireWire
operation, it displays
F on the front panel LEDs.
When it switches to USB operation, it displays
U on
the front panel LEDs.
To switch to Press and hold this knob while turning on the Audio
Express
FireWire LINE 3 knob
USB LINE 4 knob

INSTALLING THE AUDIO EXPRESS HARDWARE
18
CONNECT AUDIO INPUTS AND OUTPUTS
Here are a few things to keep in mind as you are
making audio connections to other devices.
Mic/instrument inputs
Connect a microphone,guitar, instrument or other
analog input to the XLR/TRS combo jack 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 mic inputs (because of the preamps). Use the
separate quarter-inch inputs instead.
Phantom power
If you are connecting a condenser microphone or
other device that requires phantom power, enable
phantom power as follows:
1 Push the MIX knob repeatedly until the green
trim LED is illuminated on the front panel.
2 Push and hold the corresponding MIC knob for
a few seconds to toggle phantom power. The red
48V LED will turn on or off accordingly.
Tri m
The XLR mic input and the TRS instrument input
are equipped with 60 dB and 22 dB of trim control,
respectively. Use the digital trim encoders on the
front panel to adjust the input level for each input
as follows:
1 Push the MIX knob repeatedly until the green
trim LED is illuminated on the front panel.
2 Turn the MIC knob to adjust the trim.
The ten-segment MIC/INST meters provide visual
feedback as you turn the knob.TheAudio Express’s
input trims are digitally controlled, so they allow
you to make fine-tuned adjustments in
approximately 1dB increments.You can also adjust
trim in the MOTU CueMix FX software.See “Input
trim” on page 59.
20 dB pad
Each XLR mic input is equipped with a -20 dB pad.
To toggle the pad for a mic input:
1 Push the MIX knob repeatedly until the green
trim LED is illuminated on the front panel.
2 Push the MIC knob to toggle the pad. The
amber pad LED will turn on or off accordingly.
Combo jack summary
Use these general guidelines for the 48V phantom
power, pad and trim settings on the two combo
input jacks:
Quarter-inch analog
The quarter-inch analog inputs (3-4) and outputs
(1-4) are balanced (TRS) connectors that can also
accept an unbalanced plug.
The quarter-inch outputs are calibrated to produce
a +4 dBu line level output signal.
Quarter-inch analog input trims
The quarter-inch inputs are calibrated to
accommodate either +4 dBu or -10 dBV signals
and are equipped with digitally controlled analog
trims that provide +22 dB of gain.You can use
either the front panel knobs or the included
CueMix FX software to adjust the input trim. To
adjust these trims using CueMix FX, see “Input
trim” on page 59. To adjust the trims using the
front panel knobs:
1 Push the MIX knob repeatedly until the green
trim LED is illuminated on the front panel.
2 Turn the corresponding LINE knob to adjust
the trim.
Input 48V Pad Trim
Condenser mic On As needed As needed
Dynamic mic Off As needed As needed
Guitar Off As needed As needed

INSTALLING THE AUDIO EXPRESS HARDWARE
19
Main outs
In a standard studio configuration, the main outs
are intended for a pair of studio monitors,but they
can also be used as regular outputs for any
purpose. Their reference level is +4dB. Use the
front panel VOL knob to adjust the Main out
volume. Push the VOL knob until you see
+main
LED turn red (or flash red) and then turn it to
adjust the main output volume.
S/PDIF
If you make a S/PDIF digital audio connection to
another device, be sure to review the digital audio
clocking issues,as explained in “Connect and sync
S/PDIF devices” on page 20.
The Audio Express on-board mixer also supplies
12dB of digital trim adjustment for the S/PDIF
input pair, which can be adjusted from CueMix FX
(“Input trim” on page 59) or the front panel (using
the same procedure as explained earlier for
“Quarter-inch analog input trims” above).
CONNECT MIDI GEAR
Connect your MIDI device’s MIDI IN jack to the
Audio Express’s MIDI OUT jack (Connection A
below). Conversely, connect the MIDI device’s
MIDI OUT jack to the Audio Express’s MIDI IN
jack (Connection B).
Figure 3-3: Connecting a MIDI device to the Audio Express.
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 3-3. 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 Audio Express to the
MIDI IN on the additional device as shown below
in Figure 3-4.The two devices then share the Audio
Express’s MIDI OUT port. This means that they
share the same set of 16 MIDI channels, too, so try
to do this with devices that receive on only one
MIDI channel (such as effects modules) so their
receive channels don’t conflict with one another.
Figure 3-4: Connecting additional devices with MIDI THRU ports.
Audio Express
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
Additional device
Audio Express
rear panel

INSTALLING THE AUDIO EXPRESS HARDWARE
20
CONNECT AND SYNC S/PDIF DEVICES
DAT decks and other devices with S/PDIF digital
I/O will sync to the Audio Express via the
S/PDIF connection itself. Just connect it to the
Audio Express via the S/PDIF connectors. When
the device records a digital audio signal (from the
Audio Express), it will simply synchronize to the
clock provided by the digital audio input from the
Audio Express.
When recording digital audio into your host audio
software via the Audio Express’s S/PDIF input, you
can either resolve the external device to the Audio
Express, as described above, or you can resolve the
Audio Express to its S/PDIF input.
Figure 3-5: The setup for synchronizing a S/PDIF device with the
Audio Express.Sync is achieved via the digital I/O connection itself.In
this case, you have to choose S/PDIF as the Audio Express’s clock
source when resolving it to the other device.
POWER OPTIONS
The Audio Express can draw power from two
possible sources:
1. the computer via FireWire, or
2. a DC power supply.
If you use USB2 to connect to your computer, you
must also use the DC power supply included with
your Audio Express, as USB2 does not supply
enough power by itself.
Bus power requirements
The Audio Express draws all the power it needs
from the FireWire bus connection to the computer.
However,the FireWire connection to the computer
must meet all of the requirements discussed below.
6-pin FireWire connectors
The Audio Express can only draw power over the
FireWire bus from a 6-pin to 6-pin cable,or a 6-pin
to 9-pin (FireWire B) cable. It cannot draw power
from a FireWire cable with a 4-pin connector, as
shown below:
Figure 3-6: 4-pin FireWire connectors cannot be used for bus power.
When operating under bus power,daisy-chaining
is not recommended
The Audio Express can be daisy-chained with
other FireWire devices from a single FireWire
connection to the computer. However, if the Audio
Express is operating under bus power, this is not
recommended. If you need to daisy chain the
Audio Express with other devices on the same
FireWire bus, power the Audio Express with the
included power adapter. The other devices on the
chain should also have their own power supply. In
general, bus-powered FireWire devices should not
be daisy-chained.
FireWire adapter products must be powered
If you are using a FireWire adapter (a third-party
product that supplies one or more FireWire ports
to your computer), it must have direct access to a
power supply:
■
PCI FireWire cards
— If you plan to connect the
Audio Express to a PCI card and run the Audio
Express under bus power, the PCI card must have a
S/PDIF
S/PDIF device
Audio Express
Audio Express
Clock Source setting =
Internal (when resolving the other
device to the Audio Express)
Audio Express
Clock Source setting =
S/PDIF (when resolving the Audio
Express to the other device)
S/PDIF
6-pin FireWire
4-pin FireWire
✓✗
YES NO