Motu M4 Audio Interface Review

[ahhui]

Do you mean DT900 Pro X? I couldn't find any information about DT990 Pro X. I have found DT900 Pro X and they have 48 ohms impedance and 100 dB SPL sensitivity. They should work well with the M4 device.

I apologize, yes it's DT900 Pro X. Thank you for your advice, I'm going to buy one.

 

[PollardPhotography]

Hi All,

Long-time lurker, brand new poster.

I've had the MOTU M4 for several months and it has been great. I've been using an old pair of throwaway headphones that finally bit the dust and after much research decided to replace them with a pair of Beyerdynamic DT 770 Pro 250s.

Previously, the M4 headphone output was totally sufficient for powering my old headphones, as well as my Etymotic ER2SE IEMs. But the 250 ohm DT 770's definitely seem to need more juice as my voice comes in very quiet when using the direct monitoring feature, even with the headphone volume knob cranked on the M4. (Note: Primary input is SM7B with input gain knob at ~3 o clock. Not the most sensitive mic, but the volume of my voice was previously adequately high via direct monitor with lower impedance headphones.)

Because of that, and because I'm not sure the DT 770's are not getting enough power to shine as brightly as they can, I've decided to incorporate an external headphone amp. A bit of research turned up the Schiit Magni+ as a great entry-level choice which should have significantly more power for the DT770's and enable them to be their best while (hopefully) bringing me back up to a sufficiently high direct monitoring volume level.

I've been doing some research and have a few assumptions I'd like to clarify if there's anyone who could share some insight.

1. The Schiit Magni+ appears to be unbalanced. I plan to plug the M4's "1/2 Line Out" (RCA/unbalanced?) into the Magni+'s "IN".
Is this the best place to connect on the M4 side?
I understand this will eliminate volume control on the MOTU, but I should still be able to control volume on the Magni+ as well as in Windows.

2. Is there a major disadvantage in this use case to using an unbalanced signal chain? My research points to no, and I am not a professional (obviously), so I don't know that I'd even be able to detect a difference in fidelity unless it were stark.

3. Does direct monitoring AND the input monitor mix still work when using the Line Out on the M4? Meaning can I hear my voice/instrument through my headphones plugged into the Magni+ and can I influence the balance I heard in my headphones between the audio playing on my computer and the voice/instrument going into the M4 via the physical knob on the M4?

4. Are there any other considerations I'm missing, or recommendations?

Thanks so much for any insight you can share. This forum and thread has been a wealth of knowledge and I wouldn't be even a fraction of the way to understanding all of this without the help from the great folks here.

Thank you!

 

[studio7]

Have you tried a different mic? The SM7b has a very low output level of only 1.12 mV, and is often used in combination with the Cloudlifter CL-1.

 

[forma]

Yes i too noticed when enabling direct monitoring it lowered the output volume. So if you use that feature i can definitely see why you're finding the headphone amp lacking. I have HD600's and even without direct monitoring I find the headphone out a tad low for when in the mood to listen loud (of which i don't do often). I don't like to go beyond 3 on the dial as to my ears it starts to sound strained.

For this reason, i might add an amp ( Atom+ Hevi) to overcome the lack of power on offer. But I can certainly see why most people feel it's loud enough as i only miss a bit more power once in a blue moon.

 

[sadoMasupilami]

Hi, I have a hopefully quick question as stile relatively new to all the topics here. I would like to use the m4 for allowing a digital crossover and room correction via audiolense. My amplifier as well as my subwoofer has only RCA connections. As far as I read I would not be able to use the volume control of the M4 as the line out 3 and 4 have a fixed volume so the subwoofer would always receive 100% volume. Would it be fine from a sound quality standpoint to adjust volume from Roon or should I look for another device that allows adjusting the volume for all output channels?

 

[insane]

I remember wanting to pick this one back then when it was almost impossible to find, now that the dust has settled, I would like to pick one. My questions are:

1) If I have a Magni 3, is it worth plug in in there and keep using it, or is the headphone jack good enough that I don't need it? I have a headphone that runs at 600 ohm, others at 250 ohm, others 32 ohm... is this judged merely by how loud it gets? I want a clear neutral signal, not necesarily too loud.

2) Im running Win 10 1809 LTSC. Does anyone run this by anychance? drivers are stable?

3) Am I going to have any problems with the knobs? as asked above. I also have a pair of monitors that use XLR. I have XLR to TRS cables for the monitors. How do I plug this stuff so I can control the monitors with the big knob and the headphones with the small knob? (the headphones would be like a hard cap for safety, then I actually change the volume with the Magni 3 knob if it makes sense)

Im assuming I just have to plug the XLR to TRS cables from the monitors into "MONITOR 1 2", then the RCA to TRS cable from the Magni 3's OUTs to the m4's "LINE OUT 1 2" TRS' and that would do.

https://cdn-data.motu.com/django_prod/filer_public_thumbnails/filer_public/ff/72/ff72dc30-7851-4d02-8a03-0298f103a17a/m4_rear.png__1200x1200_q85_subsampling-2.png

https://iiwireviews.com/wp-content/uploads/2020/03/Schiit-Magni-3_2-1024x683.jpg

 

[Daverz]

Hi, I have a hopefully quick question as stile relatively new to all the topics here. I would like to use the m4 for allowing a digital crossover and room correction via audiolense. My amplifier as well as my subwoofer has only RCA connections. As far as I read I would not be able to use the volume control of the M4 as the line out 3 and 4 have a fixed volume so the subwoofer would always receive 100% volume. Would it be fine from a sound quality standpoint to adjust volume from Roon or should I look for another device that allows adjusting the volume for all output channels?

Using Roon for the volume should be fine. I would suggest keeping a 32-bit signal path throughout.

 

[sadoMasupilami]

Using Roon for the volume should be fine. I would suggest keeping a 32-bit signal path throughout.

I thought volume control in the digital domain is a bad idea but than I read that:

https://www.audiosciencereview.com/forum/index.php?attachments/whitepaper-roon-dsp-volume-measurements-pdf.131355/

As the M4 supports 32 bit I should be completely fine with Roon volume control.

Thank you!

 

[Blew]

I thought volume control in the digital domain is a bad idea but than I read that:

https://www.audiosciencereview.com/forum/index.php?attachments/whitepaper-roon-dsp-volume-measurements-pdf.131355/

As the M4 supports 32 bit I should be completely fine with Roon volume control.

Thank you!

That's when using Roon to control the DSP volume. Has anyone done similar measurements of the volume knob on the M4?

 

[antcollinet]

That's when using Roon to control the DSP volume. Has anyone done similar measurements of the volume knob on the M4?

If the M4 is using 32 (or even 24) bit math to process the signal, then there is nothing to worry about with digital volume control.

 

[Blew]

If the M4 is using 32 (or even 24) bit math to process the signal, then there is nothing to worry about with digital volume control.

How can we tell if it is?

 

[antcollinet]

How can we tell if it is?

I thought it was you that said it is.

 

[blades808]

If I use the 1/2 outputs to send to a pair of main QSC speakers, can I use the headphone monitoring port to output to a smaller pair of JBL’s in another location? The immediate obvious advantage of this would be that I could easily control the levels of both speaker sets from the Motu interface itself.

How bad is the hit to sound quality on monitors if I connect them to the headphone port and not the balanced outputs In the back?

Thank you!

 

[harrisonjr98]

3. Does direct monitoring AND the input monitor mix still work when using the Line Out on the M4? Meaning can I hear my voice/instrument through my headphones plugged into the Magni+ and can I influence the balance I heard in my headphones between the audio playing on my computer and the voice/instrument going into the M4 via the physical knob on the M4?

Did you ever figure this out? I am wondering the same.

I have a fairly messy setup right now - Scarlett 2i2 3rd gen for mic inputs but not using any of the outputs, and then a JDS Atom stack for all outputs - headphones and monitor. I would love to just get an M4 and use the line out from the (seemingly great) DAC to something like a JDS Element for headphones and call it a day.

 

[PollardPhotography]

Did you ever figure this out? I am wondering the same.

I have a fairly messy setup right now - Scarlett 2i2 3rd gen for mic inputs but not using any of the outputs, and then a JDS Atom stack for all outputs - headphones and monitor. I would love to just get an M4 and use the line out from the (seemingly great) DAC to something like a JDS Element for headphones and call it a day.

Line Out- no. Monitor out- yes. You can just use monitor out and it works great.

 

[harrisonjr98]

Ah man I was hoping it would work with the line outs but that makes sense. I was hoping not to use the monitor outs to the JDS, to remove that unneeded attenuation knob from the signal chain.

 

[dasdoing]

the monitor outs are line outs 1 and 2. they are just called monitor outs because they can monitor the 4 inputs

 

[dasdoing]

and with the mix knob you mix PC output with the input monitor.
not that I have one, but this is what I see on the pictures

 

[harrisonjr98]

the monitor outs are line outs 1 and 2. they are just called monitor outs because they can monitor the 4 inputs

But they're controlled by the "monitor" knob which attenuates the signal (or, at the very least, is in the signal path even if maxed) as opposed to the line outs which are constant line level, no?

 

[dasdoing]

But they're controlled by the "monitor" knob which attenuates the signal (or, at the very least, is in the signal path even if maxed) as opposed to the line outs which are constant line level, no?

sure, but I don't think it is in the signal path if you max it. those knobs are digital most of the time. I once hade a interface with an analog atentuator knob and I tell you they are not very reliable. I think the industry ditched them because of this. If I am wrong here guys, correct me. But I doubt it's analog