What's going on? Recording latency and track delay

Discussion of music production, audio, equipment and any related topics, either with or without Ableton Live
0x80
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Joined: Mon Nov 09, 2009 4:51 pm

What's going on? Recording latency and track delay

Post by 0x80 » Sun Mar 31, 2013 9:17 pm

I'm trying to record audio from an external device triggered via midi. How basic can you get. I can not seem to figure it out! At first I thought it was related to my hardware midi sequencer, which is synced via midi clock to Live. But I've now narrowed the problem down to just plain audio i/o and it's still there. This is how I'm testing:

I have a kick sequenced in a software using a drumrack. On this kick I put an aux bus to send it to an external output. This output is hard patched directly to an input with a cable. I am recording the input. What I would expect is a latency in the recorded audio of exactly the ms reported in the Live audio preferences. Output buffer + input buffer = total latency. If you then use this latency to set the a negative delay on the recorded track (-latency) it should line up nicely with the original kickdrum sequence. Right??

I'm working at 48khz 256 sample buffers. Live is reporting that my overall latency should be 14.3ms (6.96ms input, 7.35ms output)

I record a bit of the kick sequence in a clip. The recorded audio is off by about 32ms. That is already something I don't understand. How is it off by about twice the total latency?

I set the track delay of the recoded track to -32ms. When I play the it with the original kick, the two line up nicely. Now I do a second recording, but when I check the recorded audio is off by 42 ms! So the current setting of -32ms track delay is not sufficient to line up the second recorded clip with the original sequence.

What I discovered is that if I leave the recorded track delay time set to 32ms the next recording will be off more than 32ms. If I first set the track delay back to 0 before I press record, the recorded audio is always 32ms off.

So my question is:
- Where does this 32ms come from?
- How does this track delay affect the recording audio?
- How I'm I supposed to record multiple takes of audio if the latency keeps moving around after you set a delay time in the recording track?

An easy way to check how much latency there is on the recorded track is to turn off "warp" and move the most right box of the start marker. It will show the milliseconds when you line up with the first hit.

Who is messing with me here. Live, my audio drivers, ...? This is my setup:
RME Fireface 400
OSX 10.8.3
Live 9.0.2

I hope someone makes sense out of all this.

0x80
Posts: 35
Joined: Mon Nov 09, 2009 4:51 pm

Re: What's going on? Recording latency and track delay

Post by 0x80 » Mon Apr 01, 2013 12:03 pm

Anybody?

nbinder
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Re: What's going on? Recording latency and track delay

Post by nbinder » Mon Apr 01, 2013 12:32 pm

Any additional effects on the channel? Any other effects in the live set?

3dot...
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Re: What's going on? Recording latency and track delay

Post by 3dot... » Mon Apr 01, 2013 12:41 pm

are there any fx in the chain?
are you monitoring from Live or from mixer?
did you set Midi clock latency correctly ?
did you set the 'driver error compensation' like in the built-in tutorial?
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0x80
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Re: What's going on? Recording latency and track delay

Post by 0x80 » Mon Apr 01, 2013 3:10 pm

No fx, I'm testing only with one instrument track (drumrack), one return track (to send kick to outlet simultaneously) and one audio track to record the 2 together.

I'm monitoring from live.

Midi clock latency is not relevant now, since I play and record audio only now. I have removed my midi sequencer from this test.

When I do the tutorial on driver error compensation, my computer shows no delay. That is possible right? Or is there something fishy about this?

I found this from another RME user:
https://www.ableton.com/answers/no-driv ... he-rme-ufx

0x80
Posts: 35
Joined: Mon Nov 09, 2009 4:51 pm

Re: What's going on? Recording latency and track delay

Post by 0x80 » Fri Apr 05, 2013 3:36 pm

Support asked me to use the latest 9.03 beta and try again. This time it didn't record the audio 32ms late, but 32 early. I found a clue though. When I have the recording track monitoring input set to "auto" it will record early/late. When I set the input to "off" it records the audio exactly in sync.

Is this expected behaviour, and if so, why does it work like this? I can't understand how it is able to record the input exactly in sync with my original kickdrum track. The audio is going out of my soundcard, and back in again with a loopback patch cable. How can Live know that the audio is passing my output and input buffers, and know that the audio needs to be corrected with that amount of latency?

I understand that the latency of the audio I'm hearing depends on the type of monitoring, but this should never influence the latency of the actual audio thats being recorded right!?

I'm confused :?

0x80
Posts: 35
Joined: Mon Nov 09, 2009 4:51 pm

Re: What's going on? Recording latency and track delay

Post by 0x80 » Sat Apr 20, 2013 8:17 pm

Just for the record, I got an answer from an RME user. I already found that with input monitoring turned off I had no latency problems. I just didn't understand why I couldn't possibly record anything in sync with monitoring on. Turns out it is meant to work like that.
Ableton records midi and audio differently depending on whether you choose monitoring "OFF" or "IN"/"AUTO"
if set to "off" it will recording, it shifts events early according to buffer size latency because it assumes you are monitoring directly with no delay (like asio direct monitoring) - Cubase/studio one have this as default
if set to "in" or "auto" it shifts event later according to buffer size latency so that events are placed "when they are heard" because you compensate and play a little earlier because of the delay

This is not explained in the manual
They should definitely put this in the manual :o ...and I'm surprised support couldn't tell me this :?

ObtuseMoose
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Re: What's going on? Recording latency and track delay

Post by ObtuseMoose » Sat Apr 20, 2013 9:14 pm

0x80 wrote:Just for the record, I got an answer from an RME user....
Ableton records midi and audio differently depending on whether you choose monitoring "OFF" or "IN"/"AUTO"
if set to "off" it will recording, it shifts events early according to buffer size latency because it assumes you are monitoring directly with no delay (like asio direct monitoring) - Cubase/studio one have this as default
if set to "in" or "auto" it shifts event later according to buffer size latency so that events are placed "when they are heard" because you compensate and play a little earlier because of the delay

This is not explained in the manual
They should definitely put this in the manual :o ...and I'm surprised support couldn't tell me this :?
You get full marks for posting your question in such a clear and complete manner, and double bonus points for posting the final answer you found elsewhere. I'd noticed weirdness in latency / delay with audio, but never pursued it to the end like you did. Thanks much for your persistence and sharing the answer.

--
Moose
"all the musical ability of a blocked nostril"

0x80
Posts: 35
Joined: Mon Nov 09, 2009 4:51 pm

Re: What's going on? Recording latency and track delay

Post by 0x80 » Sat Apr 20, 2013 9:19 pm

Good to hear that this is helpful to others :) Makes me feel a little better about the time and frustration that went into this stupid thing.

3dot...
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Re: What's going on? Recording latency and track delay

Post by 3dot... » Sat Apr 20, 2013 10:37 pm

well .. this is the normal behavior

explanation:
when you're monitoring through live..
and playback.. you want to hear it in the same (offset) way (with 'input latency')

while when you're monitoring through a mixer..
and monitor mode 'off'..
you want to be played back like you've heard it through the mixer..
("before" input latency)

hope this makes sense..
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Schmidi
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Re: What's going on? Recording latency and track delay

Post by Schmidi » Sun Apr 21, 2013 7:12 pm

I had this same issue in v8. I eventually gave up on the hope of recording anything from an external source without the assumption that I would have to later reposition my warp markers. :(

0x80
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Joined: Mon Nov 09, 2009 4:51 pm

Re: What's going on? Recording latency and track delay

Post by 0x80 » Mon Apr 22, 2013 1:11 pm

@3dot I understand it makes sense in a way, especially for listening and when playing an instrument along with that. But the main confusion comes from the recording part. I didn't expect my audio to be recorded differently depending on the monitoring setting.

For example I have an external sequencer synced through midi clock. When I start live my sequencer runs perfectly in sync. When I want to record audio from a device which is triggered by the sequencer, I need to keep monitoring off. If I turn monitoring on just because I'm curious to hear what the input sounds like in Live, then the audio is recorded with a latency! I know why it happens now, but it's something you should be aware of, so a warning is in place I think.

Support pointed me to this article where it explains this behavior is configurable.
https://www.ableton.com/en/articles/pla ... imization/

3dot...
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Re: What's going on? Recording latency and track delay

Post by 3dot... » Mon Apr 22, 2013 2:05 pm

they should update it.. I think 'strict delay comp' is on by default now..
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7G
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Re: What's going on? Recording latency and track delay

Post by 7G » Tue Apr 23, 2013 12:11 am

First things first...
1)External Device "Master"->Ableton "Slave"-> Switch on EXT (Delay Compensation ON)
(this can be done in Midi prefs via Sync button)
2)Load an External Instrument that corresponds to your device
3)Hit the metronome,go back to Midi prefs and adjust incoming latency
That's it...

UltimateOutsider
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Re: What's going on? Recording latency and track delay

Post by UltimateOutsider » Tue Apr 23, 2013 12:21 am

0x80 wrote:Just for the record, I got an answer from an RME user. I already found that with input monitoring turned off I had no latency problems. I just didn't understand why I couldn't possibly record anything in sync with monitoring on. Turns out it is meant to work like that.
Ableton records midi and audio differently depending on whether you choose monitoring "OFF" or "IN"/"AUTO"
if set to "off" it will recording, it shifts events early according to buffer size latency because it assumes you are monitoring directly with no delay (like asio direct monitoring) - Cubase/studio one have this as default
if set to "in" or "auto" it shifts event later according to buffer size latency so that events are placed "when they are heard" because you compensate and play a little earlier because of the delay

This is not explained in the manual
They should definitely put this in the manual :o ...and I'm surprised support couldn't tell me this :?
Oh man, this is awesome. I always just assumed, "this is just what you gotta put up with in Live" and just automatically shifted my audio tracks to line up properly as soon as I recorded them. (Was just doing this last night in fact.)

I'm gonna experiment a bit with this stuff tonight. Thanks!

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