Motu M4 Interface: Unexpectedly Decent AIO

I've been enjoying M4 for several days. Honestly I didn't expect much when picking it up -- only hoping it has a A/D converter decent enough to adventure dac measurements. What I knew was M4 had ES9016 to do D to A conversion. Neither 9038, 9028, nor 9018.. pretty outdated (released 12 years ago) chip. My expectation was fairly low, just hoped it to be functional.

It didn't take many days until I realized my assumption was wrong. Their dac was far from crap. Moreover, their built-in headphone out was exceptionally impressive to the point I can recommend M4 (as a good budget AIO) to others. Below was my initial impression.



Let me first be clear. Its dac is -- of course -- not in the league of $$-$$$ D/S converters such as matrix sabre pro. Its headamp wasn't as competent as that of Solaris dac, either. But I do argue when it comes to price-wise fair contest, as a complete package of one AIO, its playback performance is no slouch compared to Zen dac, Modi-Magni stack, and any Topping I heard to date. Note that the first two are what I've been recommending for starters.


Setup


Not much to talk. Super easy. Users only need to follow instructions written on the box. If you don't want ASIO, you can ignore them and immediately enjoy with default usb driver. And if you intend to connect it to external amps, I'd suggest to install ASIO4ALL. Refer to this post for more details.



The native (ASIO) driver has extremely simple configuration screen. A lot simpler than more sophisticated their higher end products such as Ultralite.


M2 vs M4



If you've researched about this product before, then you might know its cheaper brother M2. I haven't used M2. So can't fully compare the two. But could be worth noting M2 is 2x2 (2 inputs and 2 outputs; M4 is 4x4) and doesn't come with fixed-level line outs (no matter balanced or unbalanced). But I'd also add that in M4, analog attenuation has not caused any deal-breaking sonic degradation to me.


Listening

My evaluating configuration below.

• DAC evaluation: Motu M4 (Line outs 3-4) → Geshilli Erish → Headphones (mostly ZMF Verite)
• AIO evaluation: Motu M4 (Hp out 1-2) → Headphones (mostly V-Moda M200)
• Other associated gears: Schiit Modius, Schiit Magnius, Topping DX3

Sound: As a D/A Converter

I was blown away as M4's dac far exceeded what I expected from previous-gen Sabre. ES9016 was several generations prior to the current ES 9038 Pro. Chip spec easily differs by tens of decibel. While I don't bother such numbers, I was rather concerned that 9016 was a relic of the past when Sabre was super notorious. But there were some exceptions. LH Lab's Geek Out was clearly one of them. And I am pretty sure Motu's engineer learned a thing or two from LH directly or indirectly.

That doesn't mean M4 sounds similar with GO. Nope. Both could resemble in maturely taming Sabre trebles and transforming them to rather agreeable tonality. But M4 sounds more like Matrix's XSP with slightly degraded quality across all over the technicality criteria. Tonally warmer than Matrix but colder than LH. M4 isn't quite what I'd describe neutral, but among those three I listed, definitely the most neutral. Not surprising for its intended uses though.

I had very difficult time in describing M4's fluidity and liquidity. It feels like M4 is inherently sterile and dry, but comes with some micro thin layer with some magical ointment put on its surface. As a result, some imperfect mixture of mutually contradicting states exist in my perception. Weirdly, that creates subtle but unique organic flavor in its sounding. This "organic" feel was very evident when I ABed M4 and Modius (bal outs).

Speaking of Modius vs M4, Modius presents more grainy highs (bad), better dynamics (good), and a little higher resolution (good). On the contrary, I like M4's blacker and clearer background (maybe at a cost of lower resolution?), edgier transients, and better timing over Modius. But please take this with a grain of salt as I doubt if Modius can do equivalent justice to Erish+Verite downstream as much as 2541 or BF2. Until the day M4 arrived, Modius had to serve for headphones duties (it originally only used for speakers) as bifrost 2 gone . M4 let Modius return to its original place.

Another thing to note is its lack of density in upper midrange. Modius had similar issue in my headphones chain but M4 was a little more evident. Compared to what I favorably used (Bifrost 2, DAC 2541), M4 sounds a little hollow time to time. Not bad in reproducing dimensions but feel very fake.

Overall, Its da converting ability was exceptional for many inherent limitations: price, bus-power, and outdated chip. Very enjoyable and listenable by all means.


Sound: Built-in Head Amp

For the first few days, I didn't even dare to try hp out as I thought it would sound like shit. How foolish I was!

The built-in amp is indeed very synergistic and alleviates many shortcomings I listed above. I tested M4+Magnius vs M4 back and forth with bunch of headphones I'm having. And I found clear preference toward M4's hp out with "right" headphones.

Below are things particularly good to me

• Less veils: I didn't think I heard veil with external amps. But switching to internal amp from magnius immediately reveals much high level of transparency and disappearance of veils. I still failed to find such veil with Erish though.
• Fuller body on mids: As I stated above, there were hollowness and thinness in its playback. The builtin amp can't fully eliminate that issue, but a lot mitigated.
• Better depth-dimensionality: Reduced hollowness and improved mids contributed to more believable dimensionality and staging. That improvement combined with inherent playback nature of simplification (i.e., lower resolution), spatial cues get easier to perceive and pin-point.

But please note that the head amp isn't as complete as dedicated external amps. To be specific, I don't think M4's amp has enough authority or grasp on drivers. Any improvements listed above were more evident with easier loads (M200 and Symphone) and less or not at all with harder loads (Verite and HD650). Hemp was kinda in between, but closer to the latter group.

M200+M4 was indeed the highlight of show. This combination bonds me to the music (and to this combination). And for this combo, I can more comfortably say it's the best sub-$200 AIO I've ever heard even without its decent ADC feature. This combo sounds so nice that I have to move M200 to my primary rig and use porta pro and symphone instead for bed-loafing duties.


Measurements (Experimental)

Disclaimer: All taken by a noob. Be wary of any kind of BS

Spoiler: Balanced Out measurements

Spoiler: Unbalanced Out measurements

Additional Thought

One thing I cannot fully recommend M4 to others at this moment is Motu's own Ultralite interface comes with way more useful features (D2D, EQ, way flexible configurations, etc. -- not to mention more outs and ins) and price delta isn't distant enough (low 200 vs high 500) for features delta. Moreover, I am also pretty much sure UL can benefit from better power. Knowing how Motu could do well with 9016, UL feels like a better value.

For more info about UL: https://www.superbestaudiofriends.org/index.php?threads/motu-ultralite-mk4-review.9438/

 

Thanks for the review. Despite my ears-not-worth-spening-money-on purchase embargo, I'm still potentially up for something at the lower-cost end of things.

Way, way back, when I began my PC-based audio, and went from built-in (awful) to cheap board (a little better) to a fifty-quid (GBP) board (noticable improvement) to a hundred-quid half-price-obselete-model board from RME which I felt rivalled my Cyrus CD player, all in a matter of a few weeks, I asked the guy in the shop what his open-budget choice of interface would be and he replied MOTU. Somehow I never forgot that. But, back then, their stuff was not only expensive, but expensive because of all the included input channels, mic preamps and stuff, that I did not want. In a few words, their reputation was good a couple of decades ago.

Later (maybe one decade ago), they still had the reputation for sound, but also had one for being completely not-Linux-usable and wanting to stay that way.

Maybe not so much for Linux users, who need to google this, look at kernel levels, and decide whether they, if not running a distro with a recent kernel that supports M2/M4, are prepared to get their fingers dirty in the techie mud. Supposedly class-compliant now, which should mean absolutely-Linux-usable, they are... maybe.

Alerted by @Psalmanazar, to the low-cost-high-value potential of these new-to-me (I haven't kept up) boxes, the M2, at least, has been on my possible-exception-to-spending embargo.

I was a techie in a different lifetime (Unix systems manager indeed) but have no great enthusiasm any more. But never saying never.

 

I'm still using M4 well, but came across several bugs with its windows driver, including the followings:

• Foobar2000 WASAPI does not operate at all.
• ASIO4ALL/WaveRT works. But 88.2/96khz playback involve noticeable periodic noise.
• Native ASIO driver generates seconds of silence whenever active sampling rate changes (e.g., 44.1 -> 48).

 

I'll be honest that I am not sure the difference between WASAPI event vs push, but push works with my M2 (but not event).
If the M2 and M4 similar enough to group together, I also can't get mine to work with Redscape properly yet.

 

In push mode, the software "pushes" or sends the data to the hardware. In event mode, the hardware "pulls" or calls the data.

From what I recall reading years ago, this is mostly a hardware compatibility thing as you've noticed and shouldn't affect sound, but I don't know if anyone has tested that sort of thing.

 

Thanks for taking the time @Vtory.

I rather enjoyed the M2 as well. I upgraded to the mk4 based off of @Psalmanazar recommendations about a year ago. Differences that were worth the upgrade:

• Internal DSP; EQ, compressor, noise gate, HPF
• M2 would rarely lock up, I think this was due to USB bus. Mk4 obviously doesn't have that
• Also REALLY like the ability to set mic gain with a digital, numerical readout. I didn't realize how convenient that was until I tried a Crimson 3 recently and tried to live without

The headphone amp on the mk4 seems a little more powerful from memory, but not as clean either.
I do wish both the M2 and mk4 had the mix knob the m4 has. mk4 you have to adjust in the digital mixer and it's just not as convenient.

 

Many of the issues I have had with the MOTU M2 have been when the Buffer Size changes. While not common a user may experience a very high or slow pitch change in the audio, fun sometimes. Easy to fix, most issues I had with my M2 have been solved by either changing the sample rate, Buffer Size, or using external power via schiit wyrd

On linux these settings are much more difficult to change on the fly (default-fragment-size). It will reinitialize when many applications use more than 1 sample rate; 44.1 x 48. One might have luck messing with ~/.config/pulse/client.conf but I wasn't. My point, it isn't P&P on linux 5.1x.xx(as is often the case)

In my opinion I can not recommended this for a pulse audio application.

 

I use JACK.

I'm no "hi-res" guy, and I'm quite happy to set it at 44100 and feed it 44100, reducing the sample rate in the player. I did have a problem with that when I noticed that my favourite player of the time degraded the music, so I changed to one that didn't.

I'm currently using 4.15! (Mint 19.1). But my update manager application has up to 5.4 on offer.

 

I'm now on a fresh machine (well, new insides) with a new, clean, Linux-Mint install, and kernel 5.4, so an M2 is back on the hmm-interested list.

 

Hello bump, hello bump!

As my little firewire box seems to have died, I'm, ahem, moving towards a motu.

My standard Linux kernel was 5.4.0. I'm testing 5.8.0 as of this evening. Everything seems to be working, so I'm fairly confident to go ahead.

Does anybody know how the headphone-outs compare, M2 or M4? For quick and easy listening?

 

MOTU is known to be finicky with drivers. I know somebody who switched from MOTU to RME because he was fed up with the driver problems he was having. So maybe going with a safe bet driver wise might be a better idea. I do not know what would be the next best thing without being considerably more expensive (like RME).

 

My M2 would occasionally lock up but I'm not sure if that was a driver issue or due to USB powered.

FWIW my mk4 I am yet to have a single lock up or oddity.

TheM2 had a quieter but less powerful headphone out.

 

I've had constant problems with my MOTU m4 on Windows -- digital static on the mic inputs in particular. I'm not ready to declare victory yet, but I think they all got solved by... drumroll... plugging directly into a motherboard USB port instead of going through a powered hub.

Also, MOTU recently released a new driver. It has an option to sync the hardware's bitrate with Windows' bitrate, which I could see increasing reliability in some situations.

 

Thanks guys.

No Windows.

Upside is... No Windows, no microsoft software, no microsoft way of doing things.

Downside is... Usually stumped when it comes to upgrading hardware on devices. Last time that applied to my camera, I was lucky and had a Win laptop in the house on its way to being donated to a young student. And there is Windows software that I think I'd love to use, specifically, Capture One for photo processing.

And the news is that I ordered the M4 a couple of days ago, and it will be here in a couple of days. Big import premium: about US$335! Well, that's India and it can (often is) be worse.

USB truth is that even different ports on the motherboard can behave differently.

Using Firewire kept all that away for the past decade-plus, although the truth is that getting Firewire audio to even work properly under Linux was, at first, hell. But once it did, it just went on working.

 

I knew that 5.8, 5.11 and 5.13, although not standard, are available for my Linux Mint 20.1. I thought I'd pick the smaller jump. My upgrade manager is now offering me 5.13. Probably no harm in trying, I suppose!

 

I was on 5.16 last night and even the self monitoring feature works. I think its a go. I didn't hear any issue on my end. using pipewire to do a voip call

 

Thanks!

My requirements are the simplest: playback.

I doubt if I'll be doing any recording; I doubt I'll ever digitise vinyl again (ears).

In fact, in buying this, I'm going against a basic principle, which is not to pay for connections and capabilities I don't need, eg, why buy mic preamps that I'm not going to plug mics into!

But hey, I fancied the thing. And it doesn't cost that much.

 

Have spent an evening playing with this thing. Still am. I think we'll learn to live with each other.

On the whole, no, I don't like the headphone out. It is strident. And it needs the volume well up like 3-o'clock, for hd600, which I'm listening with just now.

Revised 21 Jan: Revisited because I didn't retest this immediately after all the kernel upgrades. No, it doesn't have much umph with HD600, but it is certainly not bad. ​

Through the amplifier (not headphone amp, actually, a Cyrus Integrated) things were a lot smoother, but I was still getting fatigued.

I've been here and there in software. I've changed things and changed them back, thus no net change, but hey, it sounds different now. It's like one of those cable reviews: every change (or not change) seemed to make things a bit better. And I think the sum of it is real, but I am just sure how much I imagined the details.

Playback seemed glitchy. was I imagining what seemed to be a slight fade every so often? I can't say for sure. But I could not be imagining the dropouts, of which there were a few, associated with x-runs. X-runs, in the past, for me, have manifested a drop-outs, a momentary but marked silence in the music. Here, they were more of a trip-up, but undeniable.

I have upgraded to kernel 5.13.23. An internet report mentioned some weird distortions on lower versions, and I think I was getting some. Maybe the system wanted to celebrate --- there seemed to be more clarity and depth to the music. Altogether more pleasant.

This is my test for those hard-to-define elements in digital music: does it make one want to stop? Or does it make one want more? Am I tapping my toe? Or am I thinking about doing something else when the song is over?

Practical problems. I was hoping to be able to use outputs 1-2 and 3-4 for different devices. I was hoping to be able to use the not-volume-controlled 3-4 for the amplifier.

aplay -l and my JACK configuration (Cadence JACK toolbox) see the M4 as one thing. I can only say, connect to M4, not specify the ports.

I can change that, in Catia. But my player disconnects and reconnects regularly and will always go back to ports 1-2. This is a bit of a pain. I have dealt with something similar in the past, but I don't remember how.

 

Scripting the power switch to work with Linux/JACK...

The Motu M4 (and M2, I think), unlike most USB-powered audio interfaces, has a power switch. We do not need to leave it on when not using it.

My audio system is based on JACK, controlled by cadence tools from KX Studio. It will connect to its configured device on startup, but it won't bother looking again if there is not one.

Today, I wrote a script, added to my start-on-login programs that looks for the M4. It goes on looping. When it finds M4 (it's been turned on) it will start cadence or tell it to start JACK and the alsa bridge. It will continue to loop, telling JACK to stop if the M4 goes missing (ie has been turned off).

Just turning on was simple to handle. Turning off, and turning on again was a little harder to work out.

Shell scripts used to be part of the day job, but I got rusty. Like, it took me ages to work out that I had left the '$' off one $VARIABLE when reading it. I got very rusty.

 

This just burned me. Except I’m trying to use this thing with i(Pad)OS, not Linux, so I can’t just write a script to enable outputs 3-4. I even contacted Motu support, and was told that the outputs can only be specifically routed in (DAW) software. Which most audio software I have on my iPad does not support. If I’d known that, I’d have just bought the M2.

Judging from its manual, the Lynx Hilo does the right thing here with regard to flexible routing and not needing a software tether, but it’s a far more expensive device.