• Welcome to ASR. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Motu M4 Audio Interface Review

CJYYZ said:
Any M4 owners up for doing some experimenting? First off, can you connect the M4 directly to a phone and pass audio from it to the phone for a Facebook live stream?
Click to expand...

Yes you should be able to power the M4 directly from your phone using a USB-C to USB-C cable. So, depending on your phone's battery capacity, you may not even need the power bank/hub.

From the manual:
1768257333439.png
 
Blew said:
Yes you should be able to power the M4 directly from your phone using a USB-C to USB-C cable. So, depending on your phone's battery capacity, you may not even need the power bank/hub.

From the manual:
View attachment 503715
Click to expand...
That would be ideal, but I'll need to maintain a 3 hour Facebook Live stream and power the M4... I doubt a phone could pull that off without an external power source.
 
CJYYZ said:
Hmmm... I never thought about whether or not the M4 can handle power delivery on its own. I guess it's designed to connect to a computer, which would handle the power delivery to it. Do you think I would need to connect a powered hub to the power bank? I was hoping a power bank with multiple USB-C connections would act as a hub, to simplify the whole setup.
Click to expand...
The M4 doesn't have to handle USB PD - the hub will just supply it 5V. It's about how the hub, PSU and computer or phone negotiate power handling so the PSU can power everything. A hub/adapter like this has a USB-C port marked 'PD' that you can connect the PSU to, and a captive USB-C plug to go to the laptop or phone. The M4, or in my case the speakers, can connect to one of the other USB ports on the hub/adapter. With the laptop, and with some more recent phones, the laptop or phone charges quickly and playback to the speakers works exactly as it should. With the Pixel 3a the phone charges quickly, but can't play to the speakers even though it ought to work.
 
somebodyelse said:
The M4 doesn't have to handle USB PD - the hub will just supply it 5V. It's about how the hub, PSU and computer or phone negotiate power handling so the PSU can power everything. A hub/adapter like this has a USB-C port marked 'PD' that you can connect the PSU to, and a captive USB-C plug to go to the laptop or phone. The M4, or in my case the speakers, can connect to one of the other USB ports on the hub/adapter. With the laptop, and with some more recent phones, the laptop or phone charges quickly and playback to the speakers works exactly as it should. With the Pixel 3a the phone charges quickly, but can't play to the speakers even though it ought to work.
Click to expand...
I was hoping to avoid having to use a hub and just go with a power bank with multiple usb-c ports. Do you think that's possible, or is a hub required to get the phone and the M4 to talk to each other?
 
CJYYZ said:
I was hoping to avoid having to use a hub and just go with a power bank with multiple usb-c ports. Do you think that's possible, or is a hub required to get the phone and the M4 to talk to each other?
Click to expand...
You mean plug the phone into the power bank, and the M4 into the power bank? In that case there's no communication route between the phone and the M4 (unless the power bank has a built in hub - I've not heard of one, but it's possible...) There are some pretty compact ones like the UGreen 60165 aimed at charging a phone while using a USB headphone adapter.
 
somebodyelse said:
You mean plug the phone into the power bank, and the M4 into the power bank? In that case there's no communication route between the phone and the M4 (unless the power bank has a built in hub - I've not heard of one, but it's possible...) There are some pretty compact ones like the UGreen 60165 aimed at charging a phone while using a USB headphone adapter.
Click to expand...
I see... It looks like I'm going to have to research all the components I'll need, buy them and hope it all works. Fingers crossed. Thanks for your advice.
 
There are special Y-adapter cables for smartphones with 1 USB-C connector and 2 USB-C plugs, one to supply power to the phone and one for everything else.
 
This might be a noob mistake, but I was pulling my hair out trying to make a loopback sound card calibration measurement of my M4 in REW, because the input level was too low no matter what I did (changing channels, swapping TS or TRS cables etc).

It turns out it was the "output channel mapping" in REW. The defaults don't correspond to what is labeled on the M4. Output channels 3/4 are labeled L/R on the M4, but in REW they are named C and LFE by default.
 
somebodyelse said:
You mean plug the phone into the power bank, and the M4 into the power bank? In that case there's no communication route between the phone and the M4 (unless the power bank has a built in hub - I've not heard of one, but it's possible...) There are some pretty compact ones like the UGreen 60165 aimed at charging a phone while using a USB headphone adapter.
Click to expand...
I found a couple of power banks with integrated usb-c hubs. They are even more expensive than the MOTU M4! Yikes... I guess I'll be using a separate hub.
 
Having a weird issue with my M4. I am trying to use it to record some vocals into Logic (14" M1 Pro MBP running Tahoe 26.3), and have this weird buzzy artifact/noise happening. They are quick little <1s bursts that almost sound like some kind of digital/USB noise artifact. It is like a stock library sample of a little electrical zap sound. Oddly they are seemingly "triggered" most often by transients when I go to speak/sing, ie I'll start a recording and then 20 seconds later the moment I start to speak, the buzz immediately happens. They are not caused by transients 100% of the time but the correlation felt too strange not to note. It is not input/preamp gain clipping, the actual recordings are peaking around -15 and I am seeing the issue no matter how low I go with the preamp gain.

Things I have tried, and the issue still occurs:

-different microphone (first saw it happen on a condenser that was using phantom power, tried a dynamic and it still happened)
-different DAW
-M4 directly plugged into USB port on Mac and not CalDigit TS4 dock, as it usually is.
-different USB port on Mac
-different USB cable
-different XLR cable

I do not have another bus-powered interface to compare but on my larger Focusrite 18i20 4th gen, 18i20 3rd gen and Clarett+ 8Pre (all take AC power in) this issue is not present.

I was looking at trying a USB ground loop isolator like the one that JDS makes, but they are fairly expensive for a shot-in-the-dark solution.

Anyone else dealt with this problem and/or discovered a fix?
 
Beware of updating the firmware - my M4 locked itself permanently in update mode. Will NOT come out, and it's out of warranty, and my past experience with MOTU support mostly consisted of them blaming my own hardware.

Weird clipping/distortion preceded the failure, and earlier firmware versions gave very strange "bitcrushed" style audio. Not saying this will happen to everyone, but I can't guarantee it wasn't the firmware or not, or if mine had a masked issue the firmware update catalyzed.
 
harrisonjr98 said:
Having a weird issue with my M4. I am trying to use it to record some vocals into Logic (14" M1 Pro MBP running Tahoe 26.3), and have this weird buzzy artifact/noise happening. They are quick little <1s bursts that almost sound like some kind of digital/USB noise artifact. It is like a stock library sample of a little electrical zap sound. Oddly they are seemingly "triggered" most often by transients when I go to speak/sing, ie I'll start a recording and then 20 seconds later the moment I start to speak, the buzz immediately happens. They are not caused by transients 100% of the time but the correlation felt too strange not to note. It is not input/preamp gain clipping, the actual recordings are peaking around -15 and I am seeing the issue no matter how low I go with the preamp gain.

Things I have tried, and the issue still occurs:

-different microphone (first saw it happen on a condenser that was using phantom power, tried a dynamic and it still happened)
-different DAW
-M4 directly plugged into USB port on Mac and not CalDigit TS4 dock, as it usually is.
-different USB port on Mac
-different USB cable
-different XLR cable

I do not have another bus-powered interface to compare but on my larger Focusrite 18i20 4th gen, 18i20 3rd gen and Clarett+ 8Pre (all take AC power in) this issue is not present.

I was looking at trying a USB ground loop isolator like the one that JDS makes, but they are fairly expensive for a shot-in-the-dark solution.

Anyone else dealt with this problem and/or discovered a fix?
Click to expand...
Does changing the buffer size do anything? Is "low latency offsets" turned on? This can cause glitches with some systems. These come up with the driver with windows, dont know how to see them on a mac.
 
harrisonjr98 said:
Having a weird issue with my M4. I am trying to use it to record some vocals into Logic (14" M1 Pro MBP running Tahoe 26.3), and have this weird buzzy artifact/noise happening. They are quick little <1s bursts that almost sound like some kind of digital/USB noise artifact. It is like a stock library sample of a little electrical zap sound. Oddly they are seemingly "triggered" most often by transients when I go to speak/sing, ie I'll start a recording and then 20 seconds later the moment I start to speak, the buzz immediately happens. They are not caused by transients 100% of the time but the correlation felt too strange not to note. It is not input/preamp gain clipping, the actual recordings are peaking around -15 and I am seeing the issue no matter how low I go with the preamp gain.

Things I have tried, and the issue still occurs:

-different microphone (first saw it happen on a condenser that was using phantom power, tried a dynamic and it still happened)
-different DAW
-M4 directly plugged into USB port on Mac and not CalDigit TS4 dock, as it usually is.
-different USB port on Mac
-different USB cable
-different XLR cable

I do not have another bus-powered interface to compare but on my larger Focusrite 18i20 4th gen, 18i20 3rd gen and Clarett+ 8Pre (all take AC power in) this issue is not present.

I was looking at trying a USB ground loop isolator like the one that JDS makes, but they are fairly expensive for a shot-in-the-dark solution.

Anyone else dealt with this problem and/or discovered a fix?
Click to expand...

Did you say you are bus powering the motu? If so give it an external PSU.

Try getting as clean an audio path as possible (software wise). For a test use audacity to record. Unload any sound related stuff you've got going on - eg soundsource and it's plug ins. etc etc. Unload anything else you have that interfaces with Audio.

Try a different (new) user account. If you can get to the point noise is not an issue - then load things back one at a time until it reappears - then you know the culprit.
 
Well, happy to report that after updating the firmware and doing a couple of preliminary tests I have not been able to reproduce the issue. It was intermittent but regular enough that I think I would've run into it again by now. I feel like a bit of a doofus for not checking firmware as a first troubleshooting step, but in my defense when checking the dates it looks like I installed the 09/2025 update on the 2nd of Feb, so just a few days before the next update landed and recently enough that in my brain I was still definitely "up to date" haha.
 
You must log in or register to reply here.

Similar threads

S
Motu M4 for vinyl ripping
Replies
2
Views
898
ScotDP70
S
Shrek6
creating a loopback in REW with MOTU M4 and WiiM Amp Ultra. No line out, but... subwoofer out?
Replies
1
Views
373
staticV3
staticV3
L
MOTU Stage B‑16 on Windows 11 – ASIO Driver Not Installing / DAWs Can’t Initialize
Replies
3
Views
566
Philbo King
P
J
Make MOTU M6 LINE OUT mirror MONITOR outputs?
Replies
3
Views
945
AnalogSteph
AnalogSteph
amirm
  • Poll Poll
Lynx Hilo 2 Audio Interface Review
2 3 4
Replies
73
Views
30K
xema
X
Back
Top Bottom