Motu M2 Review (Audio Interface)

[phoenixsong]

headphone-power-table-2.pdf (wordpress.com)
This is an extremely helpful resource/guide (especially when paired with the measurements here) if you're unsure of how loud you can go on certain headphones with certain devices. I think credits go to solderdude, correct me if I am wrong

 

[umbral]

You sound rather new- as such, for a first interface the Motu M2 is probably the best all rounder and more than enough. The DAC section is good enough to impress me, and I have been a semi-audiophile since nearly a decade ago. I would say the ADC section is good enough to be end-game unless you're looking to record multi-channel complex mixes or super-clean studio recordings with mics costing upwards of $1000. The amp section isn't an issue for me- for my uses I find anything with decent sensitivity and reasonable resistance drivable through it with enough headroom, and clipping usually starts somewhere between the 2-3 o'clock position on the headphone volume knob. Even if the in-built amp is not powerful enough, you can easily get a ridiculously powerful and clean standalone balanced-in amplifier to pair with it via its balanced out connections.

In terms of features, the Motu M2 is heavily laden for its price. Out of the interfaces you mentioned, only the Focusrite Clarett series has been measured to be in another league- and that is only for its ADC section. Do bear in mind diminishing returns and the extra cost though, and also the fact that in suboptimal conditions with non-TOTL equipment, an ADC of the Motu M2's standard is probably all you ever require. There are many comparisons and sound demos available on Youtube- if you are unsure of differences after listening to those, chances are you do not need or are unable to measure up to something better than the M2 (current listening equipment limited). It's been said that when it comes to recording, skill is paramount as long as you have somewhat decent equipment at hand

headphone-power-table-2.pdf (wordpress.com)
This is an extremely helpful resource/guide (especially when paired with the measurements here) if you're unsure of how loud you can go on certain headphones with certain devices. I think credits go to solderdude, correct me if I am wrong

Thank you for your excellent reply.

I am moving from USB Microphone to a XLR one + Audio interface.

I have quite a good integrated audio chip and isolated circuits on an expensive motherboard at the moment.

• 121dB SNR AMP-UP Audio with ALC1220 & High-End ESS SABRE 9018 DAC with WIMA audio capacitors. High-Res music (32bit, 384kHz PCM)

Click here : https://www.gigabyte.com/Motherboard/Z370-AORUS-Gaming-7-rev-10
Then press: Aurus Audio and also + Learn more about AORUS AUDIO for more details.

It does have a Smart Headphone AMP, but not sure what is the max ohm it can drive ?
The 32 ohm headphones i have are very easy to be driven to crazy levels with this motherboard.

The Motu M2 says it can drive even 600 ohm ?
https://linustechtips.com/topic/1298561-can-this-motu-m2-run-dt-990-600-ohm/
"The answer is 107dB is the max SPL the M2 can run the DT990 600 ohms at"

If this is true then the 250 ohm would be enough for M2 and no problem to be powered by the lower powered Motu M2 headphone amplifier ?
What about the motherboard audio chip ? ES9018 Sabre Reference.

https://www.diyaudio.com/forums/digital-line-level/117238-ess-sabre-reference-dac-8-channel-134.html
"The ESS DACs are a bit special. They are voltage output DACs, but they have a small resistance (~200 ohm) in series with their output. This means that they can be used either into a high impedance as a voltage output DAC, or into a low impedance as a current output DAC. "

"Now its just simple math.
R / S / 4 = 195.3125 ohms "

Not sure if this refers specifically to 9018, but in this case shouldn't i use/buy the Beyerdynamics DT770 PRO 80 ohm rather than the 250 ohm version, in case i don't have the Motu M2 in the room ?

I heard that the differences between 80 ohm & 250 ohm is that the 80 version has more bass and less sharp treble, while the 250 one has less bass and more sharp treble.

Any theoretical or practical differences between these two models except the cable ?

 

[phoenixsong]

Thank you for your excellent reply.

I am moving from USB Microphone to a XLR one + Audio interface.

I have quite a good integrated audio chip and isolated circuits on an expensive motherboard at the moment.

• 121dB SNR AMP-UP Audio with ALC1220 & High-End ESS SABRE 9018 DAC with WIMA audio capacitors. High-Res music (32bit, 384kHz PCM)

Click here : https://www.gigabyte.com/Motherboard/Z370-AORUS-Gaming-7-rev-10
Then press: Aurus Audio and also + Learn more about AORUS AUDIO for more details.

It does have a Smart Headphone AMP, but not sure what is the max ohm it can drive ?
The 32 ohm headphones i have are very easy to be driven to crazy levels with this motherboard.

The Motu M2 says it can drive even 600 ohm ?
https://linustechtips.com/topic/1298561-can-this-motu-m2-run-dt-990-600-ohm/
"The answer is 107dB is the max SPL the M2 can run the DT990 600 ohms at"

If this is true then the 250 ohm would be enough for M2 and no problem to be powered by the lower powered Motu M2 headphone amplifier ?
What about the motherboard audio chip ? ES9018 Sabre Reference.

https://www.diyaudio.com/forums/digital-line-level/117238-ess-sabre-reference-dac-8-channel-134.html
"The ESS DACs are a bit special. They are voltage output DACs, but they have a small resistance (~200 ohm) in series with their output. This means that they can be used either into a high impedance as a voltage output DAC, or into a low impedance as a current output DAC. "

"Now its just simple math.
R / S / 4 = 195.3125 ohms "

Not sure if this refers specifically to 9018, but in this case shouldn't i use/buy the Beyerdynamics DT770 PRO 80 ohm rather than the 250 ohm version, in case i don't have the Motu M2 in the room ?

I heard that the differences between 80 ohm & 250 ohm is that the 80 version has more bass and less sharp treble, while the 250 one has less bass and more sharp treble.

Any theoretical or practical differences between these two models except the cable ?

Best for you to look for solid measurements of the motherboard's DAC and headphone amplifier. Marketed specifications have been proven invalid time and again. Especially with regards to DAC chips used- they only reveal the potential, not the end performance. Implementation is key.

Regarding the differences between DT770s (or DT880s and DT990s for that matter) with different resistance values, there has been a ton of information and measurements published since many years ago. There really isn't any other resistance comparisons on the scale of what's been done for these models, so go and do some easy homework. I'm not sure what you mean by practical differences, but the voice coils used in versions with different resistance values are not the same, which contributes to the slight variances in their sound. Also note that there are several iterations of each apart from the resistance values (premium vs pro vs chrome vs various versions in black)

 

[umbral]

Thank you for your answers.

Can't stop thinking how Presonus 68c would compare to Motu M2/M4.
Do these specs to you or anyone else tell a good story, a better one compared to Motu interface ?
https://www.presonus.com/products/Studio-68c/tech-specs (they have quite a lot of technical information)

But the question is, are these real and how does Motu compares to them ?

https://www.thomann.de/de/presonus_...iZGUiLCJjdXJyZW5jeSI6MiwibGFuZ3VhZ2UiOiJkZSJ9

Thank you again.

 

[phoenixsong]

Thank you for your answers.

Can't stop thinking how Presonus 68c would compare to Motu M2/M4.
Do these specs to you or anyone else tell a good story, a better one compared to Motu interface ?
https://www.presonus.com/products/Studio-68c/tech-specs (they have quite a lot of technical information)

But the question is, are these real and how does Motu compares to them ?

https://www.thomann.de/de/presonus_...iZGUiLCJjdXJyZW5jeSI6MiwibGFuZ3VhZ2UiOiJkZSJ9

Thank you again.

Not sure what to make of the specs- based on those specs of theirs, the 68c has higher Mic In THD+N compared to that of even the 24c, which in this Youtube review was measured to have significantly high distortion PreSonus Studio 24c Audio Interface Review (audio quality test) - YouTube

As an owner of the M2 I'd be biased and say go for the M2 and sleep well knowing that you've made a solid purchase consistently backed by third party measurements from different sites

 

[umbral]

Not sure what to make of the specs- based on those specs of theirs, the 68c has higher Mic In THD+N compared to that of even the 24c, which in this Youtube review was measured to have significantly high distortion PreSonus Studio 24c Audio Interface Review (audio quality test) - YouTube

As an owner of the M2 I'd be biased and say go for the M2 and sleep well knowing that you've made a solid purchase consistently backed by third party measurements from different sites

Presonus fluctuates a lot on their audio interfaces in the same lineup, i saw this simple video of specs compared in a non scientific way between 24c VS 26c VS 68c VS 1810c :

(take a look)

For example 24c is quite bad on some specifications compared to other models while 68c is the almost the same as 1810c.

For 24c
ADC : 108 dB
DAC : 108 dB
Microphone Inputs
Gain Range: 50 dB
Dynamic Range: 106 dB (A-wtd, min gain)
THD + N 0.004% (1 kHz, -1 dBFS, min gain)
EIN-126 dBu (A-weighted, 150Ω, max gain)

Instrument Inputs
Gain Range 50 dB
Dynamic Range 105 dB (A-wtd, unity gain)
THD + N 0.002% (1 kHz, min gain)
Headphone Outputs
Maximum Power 47 mW / channel @ 56Ω
Dynamic Range 83 dB (A-wtd, 56Ω load)
THD + N 0.01% (1 kHz, 0 dBFS, loaded)
Impedance Working Range 32Ω to 300Ω

For 26c
ADC : 114 dB
DAC : 114 dB
Microphone Inputs
Gain Range: 70 dB
Dynamic Range: 110 dB (A-wtd, min gain)
THD + N 0.004% (1 kHz, -1 dBFS, unity gain)
EIN-125 dBu (max gain, 150Ω, A-wtd)

Instrument Inputs
Gain Range 70 dB
Dynamic Range 110 dB (A-wtd, unity gain)
THD + N 0.007% (1 kHz, -1 dBFS, min gain)
Headphone Outputs
Maximum Power 30 mW/channel (56Ω load)
Dynamic Range 104 dB (A-wtd, 56Ω load)
THD + N0.009% (1 kHz, -1 dBFS, no load)
Impedance Working Range 32Ω to 300Ω

For 68c
ADC : 114 dB
DAC : 114 dB
Microphone Inputs
Gain Range: 80 dB
Dynamic Range: 114 dB (A-wtd, min gain)
THD + N 0.007% (1 kHz, -1 dBFS, min gain)
EIN-130 dBu (max gain, 150Ω, A-wtd)

Instrument Inputs
Gain Range 70 dB
Dynamic Range 110 dB (A-wtd, unity gain)
THD + N 0.007% (1 kHz, -1 dBFS, min gain)
Headphone Outputs
Maximum Power 150 mW/channel (56Ω load)
Dynamic Range 107 dB (A-wtd, 56Ω load)
THD + N 0.002% (1 kHz, -1 dBFS, no load)

What will happen when the 3000-5000 hour capacitors die like in the article below ? :
https://www.audiosciencereview.com/...analysis-and-few-in-house-measurements.17819/

If you keep the device on, the capacitors work all the time. It will die after that ?

 

[telecode101]

thanks for review

 

[umbral]

The problem with M2 & M4 is that they moved the delivery date from 1-2 weeks for M2 to 5-7 weeks !
And for M4 from 3-4 weeks also to 5-7 weeks.

And this tells me they can do it again even when it reaches 5-7 weeks they may extend that ever further.

 

[umbral]

Found this on the internet :

Question: Connecting an amp to my Motu M2. The back line outs are connected to my speakers, and my headphones out the front. If I wanted to amp up headphones, should I do it in this manner? Interface headphone out > Amplifier > Headphones?

Answer : Yes it works like a charm.. I do this on both of my audio interfaces.
Then I can listen at room volume or where I need to hear in depth, slip the headphones on. You got it Pontiac!

Thanks : Got it - excited to try an amplifier with the Motu, will start looking around. Thanks!

The Motu M2 seems to distort (why ? is this normal on all headphone amplifiers from all other brands?) as you crank it up with a Beyerdynamic DT-770 Pro 80 Ohm.

The 32/80/250 ohm all claim you need 100mv.

My question is can you use for the Motu M2 a separate amplifier like the way it is described above ?

Can the Motu M2 support 250 ohm at all ? Or better stick with 80 ohm ?

What external amp do you recommend ?

Is there any good headphone that can be used with this interface ?

 

[phoenixsong]

Found this on the internet :

The Motu M2 seems to distort (why ? is this normal on all headphone amplifiers from all other brands?) as you crank it up with a Beyerdynamic DT-770 Pro 80 Ohm.

The 32/80/250 ohm all claim you need 100mv.

My question is can you use for the Motu M2 a separate amplifier like the way it is described above ?

Can the Motu M2 support 250 ohm at all ? Or better stick with 80 ohm ?

What external amp do you recommend ?

Is there any good headphone that can be used with this interface ?

View attachment 123597

If driving juice is not enough for your headphones (again, clipping would be obvious), an external amp would solve exactly that. Best one with balanced inputs so you can feed it with the balanced outs of the M2

 

[phoenixsong]

@umbral For the amp itself it depends on your budget. I think other people here will be able to better answer your queries on this.
A decent headphone that doesn't cost much would be the AKG K371, but at the moment it seems to be plagued with QC issues. Risk it if you dare. If you don't mind open back options you'll have more to choose from

 

[umbral]

If driving juice is not enough for your headphones (again, clipping would be obvious), an external amp would solve exactly that. Best one with balanced inputs so you can feed it with the balanced outs of the M2

Thank you very much.

So what you are saying is that instead of going: Interface headphone out > Amplifier > Headphones
I should take a balanced M2 OUT cable and connect it to an Amplifier and then connect the headphones directly to the Amplifier itself ?

 

[mrbungle]

@umbral For Amps with balanced XLR input, you need two male TRS to male XLR cables (e.g. https://www.bhphotovideo.com/c/product/1427217-REG/mogami_gold_trsxlrm_02_gold_1_4_trs_male.html), one for each channel.

 

[phoenixsong]

Thank you very much.

So what you are saying is that instead of going: Interface headphone out > Amplifier > Headphones
I should take a balanced M2 OUT cable and connect it to an Amplifier and then connect the headphones directly to the Amplifier itself ?

Yup! To clarify, there are 2 routes:
1. For easy to drive headphones/iems, Motu M2 headphone out>Headphone/Iem
2. For hard to drive ones, Motu M2 balanced outs>Headphone amp balanced ins, Headphone amp headphone out>Headphones

Of course, going balanced is a preference, not a necessity, as it has better Sinad and higher voltage out of the M2 on top of the ability to eliminate ground loops (with proper balanced cables)

 

[617]

Try the MOTU before getting an amp, it may very well be powerful enough as is.

 

[phoenixsong]

Try the MOTU before getting an amp, it may very well be powerful enough as is.

Indeed, for most of my sensitive, low resistance drivers I listen at just under the 9 o'clock position, hitting solid levels with it. My unit starts to clip approaching the 3 o'clock position, so there's still substantial headroom. I think at my listening levels I'd be fine with up to 300 ohm headphones with decent sensitivity. With 600 ohm dynamics and low resistance but insensitive planars I foresee a problem though

 

[umbral]

Thank you @mrbungle @phoenixsong &617 @somebodyelse

Excellent help !

The headphone amp in the M2 and M4 measures similarly so the answers will apply equally to both. Solderdude's downloads page includes some relevant tutorials covering power output, headphone impedance and sensitivity, and how much output you need with different headphones to hit volume levels. If the MOTU headphone output doesn't have enough power for your DT-770s you can get some more efficient headphones, or use a more powerful headphone amp connected to the line or headphone output - the line output measured a bit better, but it might not be practical to use depending on what else you want to connect. Check the master review index for headphone amps - the L30, Atom and Heresy spring to mind. Amirm's headphone reviews include a chart showing sensitivity of headphones tested in mV, although it's quite a short list at the moment. The AKG K371 might be sensitive enough to hit the volume you want with the MOTU while performing well, but do read the review.

@umbral For the amp itself it depends on your budget. I think other people here will be able to better answer your queries on this.
A decent headphone that doesn't cost much would be the AKG K371, but at the moment it seems to be plagued with QC issues. Risk it if you dare. If you don't mind open back options you'll have more to choose from

The AKG K371, now produced by Samsung since they bought Harman, yes they had a lot of problems indeed. I don't know if they still have or only in the beginning ?

This video is from 20 may 2020, 1 year and 1 month ago.

Did they fixed their quality issues ?
https://www.thomann.de/ro/akg_k_371.htm

These indeed have :

• Impedance: 32 Ohm
• Sensitivity: 114 dB SPL/ V

https://diyaudioheaven.wordpress.com/headphones/recommended-ones/

https://diyaudioheaven.files.wordpress.com/2013/03/headphone-power-table-2.pdf

Anything better or more sensitive worth considering but good quality and better frequency response compared to K371 ?
Open back headphones would get sound out and get recorded into the microphone, right ? What if you listen to lower levels, that would still be the case ? What are the better options in open back ?

The AKG ( Samsung) K371 could be powered loud enough with no problems with Motu M2 and with no distortions,, without the need to go over 75% where it distorts, yes ?

Thank you all.

 

[phoenixsong]

Thank you @mrbungle @phoenixsong &617 @somebodyelse

Excellent help !





The AKG K371, now produced by Samsung since they bought Harman, yes they had a lot of problems indeed. I don't know if they still have or only in the beginning ?

This video is from 20 may 2020, 1 year and 1 month ago.

Did they fixed their quality issues ?
https://www.thomann.de/ro/akg_k_371.htm

These indeed have :

• Impedance: 32 Ohm
• Sensitivity: 114 dB SPL/ V

https://diyaudioheaven.wordpress.com/headphones/recommended-ones/

https://diyaudioheaven.files.wordpress.com/2013/03/headphone-power-table-2.pdf

Anything better or more sensitive worth considering but good quality and better frequency response compared to K371 ?
Open back headphones would get sound out and get recorded into the microphone, right ? What if you listen to lower levels, that would still be the case ? What are the better options in open back ?

The AKG ( Samsung) K371 could be powered loud enough with no problems with Motu M2 and with no distortions,, without the need to go over 75% where it distorts, yes ?

Thank you all.

- From what we are hearing problem units are still being circulated
- Something more sensitive with a target frequency response would probably be one of the Moondrop single dynamic driver iems
- My condenser mic does not pick up sounds from the headphones I wear (but I'm starting to suspect I have below average listening levels)
- I wouldn't say "better", but the Sennheiser HD58X and Hifiman HE4XX are pretty worthy headphones that aren't too costly
- The K371 is really easy to power, don't worry too much

 

[umbral]

- From what we are hearing problem units are still being circulated
- Something more sensitive with a target frequency response would probably be one of the Moondrop single dynamic driver iems
- My condenser mic does not pick up sounds from the headphones I wear (but I'm starting to suspect I have below average listening levels)
- I wouldn't say "better", but the Sennheiser HD58X and Hifiman HE4XX are pretty worthy headphones that aren't too costly
- The K371 is really easy to power, don't worry too much

What you are saying is that there may be better options than K371 but in open format ? What kind of headphones would be "better" in open format ?
Do you think if i monitor the voice while singing in the microphone even with low levels, but with an open back headphone then 100% sure it will get into the microphone ?

Do you use closed back headphones or open back when using your condenser microphone ?

Thank you.

 

[phoenixsong]

What you are saying is that there may be better options than K371 but in open format ? What kind of headphones would be "better" in open format ?
Do you think if i monitor the voice while singing in the microphone even with low levels, but with an open back headphone then 100% sure it will get into the microphone ?

Do you use closed back headphones or open back when using your condenser microphone ?

Thank you.

What I am saying is if you are unwilling to compromise build quality, and if they still suit your needs, there are open back pairs that are worth considering too (NOT "better"). If you are monitoring then I would suggest getting an isolated pair, so open backs are out of the question- closed backs and IEMs are definitely "better" for your uses. I use both when conversing on social platforms, but for singing I prefer using IEMs instead as the levels get much louder