About to get a Motu M4, worried about all the Windows performance issue stories…

[artburda]

To my knowledge, nobody has yet measured the microphone monitoring output but I intend to do it soon. A/B'ing the direct monitor with the recorded track, the former definitely has a significant high shelf. It doesn't occur when monitoring line level sources, however.

As always, take my subjective observations with a grain of salt in the absence of measurements but what I'm hearing is not a subtle difference. I expect that it will show up in the FR once measured.

I just did such a loopback measurement with REW. Log sweep from RCA output 3 into combo input 2 (with a RCA-TS cable). Monitoring function in stereo mode. Output from headphone out into input 3 (TRS-TRS cable). Et voilà! Had to do it this way or the duplicated mono output from the left and right headphone out channels would cancel each other out.

I can't see any high shelf.

Edit: Or did you already try this? And the two front combo inputs have different circuits for direct monitoring line and mic inputs?

 

[artburda]

I just performed a test with a Rode NT-1 plugged into combo input 1. I used ableton live to route the mic input to output 3. RCA-TS cable from output 3 to input 3. I activated stereo direct monitoring. Headphone out into input 4 via TRS-TRS cable. With Visual Analyser 2020 I level matched both inputs (3 & 4) within 0.5db by playing a 440 Hz tone from my iphone into the Rode NT-1. Then I changed the frequency on my iphone (szynalski.com) in a few steps from 440 to 20'000 and I watched the channel balance very closely with Visual Analyser's Volt Meter in db mode. Again, I couldn't see any high shelf. The channel balance stayed within 1db or less. Looks to me like the direct monitoring function works like it should.

 

[Weeb Labs]

I just did such a loopback measurement with REW. Log sweep from RCA output 3 into combo input 2 (with a RCA-TS cable). Monitoring function in stereo mode. Output from headphone out into input 3 (TRS-TRS cable). Et voilà! Had to do it this way or the duplicated mono output from the left and right headphone out channels would cancel each other out.

I can't see any high shelf.

View attachment 110384
Edit: Or did you already try this? And the two front combo inputs have different circuits for direct monitoring line and mic inputs?

Thanks for that! As it turns out, I was actually hearing the absence of a low frequency boost. It had completely slipped my mind that the interface which I had previously been using exhibited high output impedance and was fudging the FR of my monitoring headphones. Oops!

Please disregard my original post.

 

[artburda]

Thanks for that! As it turns out, I was actually hearing the absence of a low frequency boost. It had completely slipped my mind that the interface which I had previously been using exhibited high output impedance and was fudging the FR of my monitoring headphones. Oops!

Please disregard my original post.

Well, now we know for sure