The MOTU 24Ao USB/AVB Audio Interface 72 Channelsfrom MOTU 24Ao USB/AVB Audio Interface 72 Channelsis a single rack space USB 2.0 interface with industry-standard AVB networking for sub-millisecond network latency, and offers twenty-four channels of analog audio output combined with three banks of ADAT optical, for a total of seventy-two channels of I/O. The unit connects to a computer through USB 2.0, which provides more than enough bandwidth for the twenty-four analog channels, and when connected through AVB networking, supports hundreds of network channels.

All devices on an AVB network can stream audio to and from a computer, and everything can be controlled simultaneously from any computers, tablets, and smart phones connected to the network. The interface delivers excellent analog performance with digitally controlled analog trim on the analog inputs, and includes a forty-eight-channel software mixer modeled after large format mixing consoles, DSP effects with 32-bit floating point precision, flexible matrix-style routing and splitting, stand-alone operation, and Wi-Fi control.

24 Balanced Analog Outputs    48 Channels ADAT I/O    Wordclock I/O    Onboard DSP    Digital Mixer with Effects    Expansive Matrix Routing    USB 2.0 and AVB Compliant    Standalone Mixing with Wireless Control    Up to 24-bit/192 kHz Resolution    Includes AudioDesk DAW Software

• Employs the same analog design as MOTU's 1248, 8M and 16A audio interfaces

• Seventy-two simultaneous audio channels: Twenty-four balanced analog outputs on three banks of multichannel connectors (D-sub and Phoenix), plus three banks of eight-channel ADAT optical

• Connects to a computer with audio class compliant high-speed USB 2.0 (compatible with USB 3.0 and iOS)

• Discovery app and web app software works alongside any host audio software

• On-board DSP with mixing and effects

• Flexible forty-eight input digital mixer modeled after large format mixing consoles, with twelve stereo busses and DSP effects, including reverb, four-band EQ, gate and compression

• DSP-driven mixing and effects engine delivers virtually unlimited headroom utilizing 32-bit floating point processing

• Modeled vintage effects processing with compression modeled after the legendary LA-2A compressor and EQ modeled after British analog console EQs

• Add a second MOTU AVB interface (24Ai, 24Ao, 1248, 8M or 16A) with a simple Cat-5e Ethernet cable

• Connect up to five MOTU interfaces using a MOTU AVB Switch (sold separately)

• Build an AVB network with multiple interfaces and computers using standard AVB switches and network cabling, with ultra-low network latency, even over long cable runs (100 meters point to point)

• Stream hundreds of audio channels among devices and computers on the network

• Matrix routing and splitting allows for sending any input to any output, or multiple outputs, including routing to and from the computer, plus any devices on the AVB network

• Control on-board DSP, mixing, device settings and network audio routing from web app software running in a preferred browser on a laptop, tablet or smart phone connected by wire or Wi-Fi to a local area network

• Standalone mixing with wireless control - connect an Apple Airport or other Wi-Fi router directly to the 24Ao with a standard Ethernet cable and control mixing and DSP effects from a smart phone or tablet, without a computer, great for live sound mixing

• Use the 24Ao as a twenty-four channel optical expander for other gear (24 channels at 44.1/48 kHz or 12 channels at 88.2/96 kHz)

• Large backlit 324 x 24 LCD allow for viewing all signal activity at a glance with detailed metering for all analog and digital I/O

• Access hardware settings from a simple and convenient menu

• Includes AudioDesk workstation software with 24-bit recording, sample-accurate editing and 32-bit mixing and mastering

Related Questions and Answers

Q: 1. This is similar to a previous question about Outputs 3&4. You answered that 3&4 will mirror 1&2 and you can use them for a separate set of monitors, which is what I plan to do. My question is can you switch between the two sets, like an A/B switch or something? Since there isn't a hard switch, is there a control panel which will do this? I'm in the Mac universe.

A: After doing some research, I see that other M4 users have asked MOTU about the same thing (switching between two sets of monitors) but it seems that the M4 does not offer that feature at this time. The only option for now is to route the two outputs to a separate mixer or A/B switch. You may want to contact MOTU directly to let them know that having the ability to switch between two sets of monitors is a desirable feature that users would like to have on the M4. You can reach MOTU by phone at 617-576-2760. Their offices are based in Cambridge, Massachusetts.

Q: 2. How many audio channels over USB are supported in class compliant mode? Can one route eg 32 channels from USB to Madi and then another 32 from adat to madi?

A: USB 2.0 (44.1 to 48 kHz): 64 in/out USB 2.0 (88.2 to 96 kHz): 32 in/out USB 2.0 (176.4 to 192 kHz): 24 in/out

Q: 3. What's the round trip latency with 64 samples @ 44.1kHz ?

A: This is the only latency specification we could find: Latency: Zero-Latency Direct Monitoring 2.5 ms at 32/96 kHz (Dependent on Buffer Size)

Q: 4. Can you send one microphone signal to both channels at the same time?

A: You would have to put the mic into a mixer first, and then come out stereo to line inputs 1 and 2, if you want one microphone to go into two inputs on this audio interface.

Q: 5. I can't get the m4 to turn itself off when the computer shuts down. Has anyone got this to work? Every other usb device does this.

A: The MOTU M4 has a physical on/ff switch, so if your computer is sleeping it will remain on. In order to have it shut down with your computer, you may have to adjust settings in your computer to stop power being sent to USB when shut down.

Q: 6. Can you connect it directly to the new IPad Air 4th gen, via USB-C, or do you need an adaptor/CCK?

A: Yes, the MOTU M4 can be connected directly to iOS devices with USB-C running iOS 9 or later using a standard USB-C to USB-C cable.

Q: 7. The specs list the the TRS outputs as DC-Coupled. Will they still work for non-DC-coupled TRS inputs on KRK monitors?

A: Yes, the DC-coupled TRS outputs on the MOTU M4 will help to send a cleaner signal from M4 to the KRK monitors. So there are no issues at all with compatibility and the DC-coupled outputs should provide better quality sound.

Q: 8. Made in USA or made in China?

A: The MOTU M4 is made in China.

Q: 9. Will this Interface work with Akai Force firmware 3.1 as USB audio interface? How many channels?

A: If this Motu interface is compatible with your computer and your Akai Force is compatible with your computer then they will both work together without any issues. USB 2.0 (44.1 to 48 kHz): 64 in/out USB 2.0 (88.2 to 96 kHz): 32 in/out USB 2.0 (176.4 to 192 kHz): 24 in/out

Q: 10. Is it possible to bypass mic preamps on m2 or m4 models? I want to use external preamp

A: You can come from your mic pre amp into the MOTU M2 or M4 at line level via the 1/4-inch TRS input in the center of the combo input connection. This would bypass the mic pre amp on the audio interface.