Some tracks out of sync when multi-track recording

[DavidPardy]

Hello, I apologise if this has already been answered but I don't think I've been searching for the right terms.

I record my drums with 8 mics, using a Behringer XR18 Air mixer, and probably about 50% of the time I will have a random number of my recorded tracks appear to start about half a beat or so later than the others. I've checked the very limited settings for the mixer's driver and minimised latency, etc. It's quick and easy enough to fix by dragging the tracks, but definitely not something I feel I should have to fix

I did notice the same problem occurred when recording from stereo input, non-Asio USB driver for a different mixer in the past, on the same computer.

I'm wondering if it's a Win10 issue? I know they changed how Windows audio works with Win7, so I'm wondering if this is related to that.

So far I've only done enough takes on my main Desktop PC to notice it occur - I've only tried a couple of times on my laptop so I'm not sure if it is going to experience the same issue.

Relevant desktop PC specs:
I5 2500k (2.8ghz I think)
8gb 1600mhz DDR3 RAM
about 6tb of drive space across three hard drives (plenty of free space on all drives)
Running Win10 Pro 64bit

Currently using Tracktion 7 but the problem occurred previously on Tracktion 6 with the old stereo mixer.

[Ben di Arrows]

You might like to check the time adjust properties of you inputs in the settings. Have you calibrated latency with a loopback?

[DavidPardy]

Thanks, Ben. I've checked all those in case they had changed, but nope, everything is fine.

It happens at random, it's not consistent, so I've already ruled out configurable latency settings. So for example, the last take I recorded today had tracks 1 and 2 start at the right time, 3 and 4 started slightly later, and 5 - 8 started the same amount later again. By comparison, the take I recorded immediately prior had no issues at all.

Could the sample size be causing issues? At the moment I'm running with the default value set by Behringer of 2048 samples, and audio quality itself is fine.

[nathanscribe]

Oddly enough I've just been experiencing this on my Mac, so I suspect it's not a Windows issue. I've been recording all week in T6 just fine, latency is all compensated for correctly, no alterations have been made - but the last audio track I recorded (played via a MIDI track) is half a beat behind for no obvious reason. I recorded three takes, all of them late. No previous takes on any of the other audio tracks in this project had this issue, it just randomly appeared and I have no idea why. I also muted all the other tracks in case plugins etc were getting in the way - no joy. The MIDI plays perfectly in time, both using a plugin softsynth and an external hardware synth - it's just the audio recording that is wrong. All other MIDI and audio tracks are spot on.

I did drop in record on this track though, rather than from the top. Could this be the issue?

[DavidPardy]

I don't think so - unless something is coded slightly differently on the Mac version. So far, all my edits are the first take/run-through from the start, some of them I've inserted the backing track as an extra track so I can create a click, but the others I'm running the backing track through a different program - I've had the delay occur in both situations.

[klangbastler]

there should be an asio driver available from behringer for this mixer. or is your issue with the asio driver?
in the past years, only asio drivers gave me stable and reliable results on different daws in windows (win 8 32bit at the moment), regarding latency correction/offset when recording.

[DavidPardy]

Yep, I'm already using Behringer's ASIO driver. It originally came set to the "Safe" audio quality setting but I adjusted this to the "Minimal Latency" setting with no difference in the occurrence of this particular problem. So I'm not totally convinced it's the driver at this point, unless this problem is only happening to people using Behringer devices based on the X32 family.

[nathanscribe]

Allen & Heath here, FWIW.

I closed the project, had a break, and went back to it - on re-opening, the problem had gone. Buffers perhaps?

[klangbastler]

i'll definitely check that here with motu and rme drivers.
things like this should not happen!

[DavidPardy]

Interestingly, over the last week or so, the problem has still been happening but to a lesser extent. The latency discrepancies are now much smaller - small fractions of a second rather than half a beat or so.

There is a possibility that my desktop computer simply has too much stuff going on and it's generating latency that way, but I can't test that until I do a recording with my laptop later this week.

[klangbastler]

i can't think of anything in tracktion doing something.
if there is no offset manually set on the inputs, it should just read the buffers and write them to disk.

so maybe asiodriver or hardware issue ...
or something in the controlsoftware in the xr18?

have you tried the windowsdrivers for the xr18 in comparison?

[lay it prodctions]

Every time you change your interface latency you need to run a signal detection on your mic inputs to get Tracktion to compensate for latency if you don't it will work sometimes and sometimes it won't. Iike I see you are experiencing.

[klangbastler]

if tracktion would have to compensate for latencies between channels of a simultaneous multichannel-recording, then there is something wrong on the driver or interface.

but i guess it is a misunderstanding. the issue here is not about a latency-compensation, that you can measure with a channel loop.
it is about an offset of some channels of a simultaneous multichannel-recording, that should not be there. a multichannel-interface and its OS audiodriver should deliver all streams at the same synchronized timepoint. the latencies of the channels of a correctly built hardware ad-unit are synchronized to the internall pll (sample clock). there should be zero offset between channels, not one sample.
when there are offsets between channels, something is wrong.

it is another thing with track after track recording (overdubbing), where in/out latencies come into play and should be measured and compensated for. normally an asio driver together with the daw does this for you automatically, regarding the audiodriver buffers inside the computer, which it knows.
the latency of the hardware ad/da (which the driver doesn't know) is pretty low and is no problem in most cases.
but it can be measured with a loop and then be compensated by the daw with a negative offset for the fileplacement, if that is of concern.

[gigazaga]

it is another thing with track after track recording (overdubbing), where in/out latencies come into play and should be measured and compensated for. normally an asio driver together with the daw does this for you automatically, regarding the audiodriver buffers inside the computer, which it knows.
the latency of the hardware ad/da (which the driver doesn't know) is pretty low and is no problem in most cases.
but it can be measured with a loop and then be compensated by the daw with a negative offset for the fileplacement, if that is of concern.

Right. I was confused about the exact problem mentioned here. If numerous track are recording simultaneously and some of them are out of sync that would be weird.

If recording sync during overdubbing is off then it is necessary to run the Auto-Detect loopback to get it locked in. Tracktion is not great at calculating recording sync and is worse for some interface technologies than others. I recommend always running Auto-Detect after making changes to the interface or Audio buffer size.

[DavidPardy]

Yes, that's correct - some tracks are out of sync, and it occurs randomly when I record, there's no obvious pattern.

It's easy enough to fix by dragging things around, but obviously that's not an ideal situation.

I haven't made any changes to the driver settings yet as I haven't had the time and I'm in the middle of recording so trying to keep everything as consistent as possible, but once I'm done with this particular job I'll experiment a bit more.