Freezing tracks not trustworthy (10.6.3)

[12bitcrunch]

I did some pre-fader freezing of tracks recently on a cpu-intensive session.

The tracks were hard panned within a stereo insert effect using Haas delays. There was no pan on the logic channels themselves

The frozen tracks were totally different! Felt panned like 30 degrees instead of 90.

it’s made me totally not want to freeze a track ever again.

can anyone share any other stories of freezing tracks going wrong?

 

 

[des99]

I've never known freeze results to be different, unless you have stuff going in and affecting plugins via a sidechain source, as that source won't be playing when you freeze a track.

I'd suggest to try to recreate this in an test empty project to see if you can replicate it.

Edited July 17, 2022 by des99

[12bitcrunch]

On 7/17/2022 at 7:36 PM, des99 said:

I've never known freeze results to be different, unless you have stuff going in and affecting plugins via a sidechain source, as that source won't be playing when you freeze a track.

I'd suggest to try to recreate this in an test empty project to see if you can replicate it.

That's a good idea. No sidechain btw, just a Haas Delay pan actioned by a stereo insert plugin.

When i'm back in my studio i'll try it in an empty session, but obviously the concern is it happening in a typically busy session! 

[12bitcrunch]

On 7/17/2022 at 7:36 PM, des99 said:

I've never known freeze results to be different, unless you have stuff going in and affecting plugins via a sidechain source, as that source won't be playing when you freeze a track.

I'd suggest to try to recreate this in an test empty project to see if you can replicate it.

So I went back into the session, confirmed the freezed files to sound different to un-freezed (unfrozen?).

Here's a screengrab of the frozen files viewed through Izotope Insight: https://www.dropbox.com/s/cqvbjvdpgqtewuq/frozen.mov?dl=0

And the unfrozen: https://www.dropbox.com/s/20kg9fwq6ccwtmp/unfrozen.mov?dl=0

Next step was to delete all the other tracks in the session. All different elements of the arrangement are in track-stacks btw.

Now the frozen files are true to the actual plugins inserted on the tracks.

Bit baffled here. Does cpu headroom affect freezing tracks?!

[des99]

No, CPU headroom is irrelevant to freezing. I haven't watched your videos yet, but the next step is to recreate this setup in a new empty project to see whether you get the same behaviour.

The reason is, if something weird just happens in one project, it doesn't necessarily mean it's a proper reproducible bug, it could be a corrupted project where all kinds of weird things can happen. If you can recreate the same thing in a new empty project, it's far easier to identify, document and report the bug...

[12bitcrunch]

2 hours ago, des99 said:

No, CPU headroom is irrelevant to freezing. I haven't watched your videos yet, but the next step is to recreate this setup in a new empty project to see whether you get the same behaviour.

The reason is, if something weird just happens in one project, it doesn't necessarily mean it's a proper reproducible bug, it could be a corrupted project where all kinds of weird things can happen. If you can recreate the same thing in a new empty project, it's far easier to identify, document and report the bug...

Cheers. The videos just show that the output is different when freezing the tracks.

Freeze is correct when deleting all other tracks in the session, freeze is correct when importing into an empty session.

But the unreliability of Logic freezing remains, so I guess I won’t be doing it in the future!

[des99]

11 minutes ago, 12bitcrunch said:

But the unreliability of Logic freezing remains, so I guess I won’t be doing it in the future!

I've been using the freeze function since it was added to Logic - at least a couple of decades now - and I've never had once instance of freeze not doing what I expect. So I have no perception of freezing being "unreliable". All that's happening so far is that you have one project where something's going on - it doesn't mean freezing is generally unreliable, or you should stop using this (very useful) feature.

I can't remember many (or any) reports of freezing being unreliable online in many Logic-related forums over the past few decades either...

Also, if this issue is fixed if you delete *other* tracks in your project, and can't be replicated elsewhere, this would also point to project-level corruption (or some mixer routing config in this project perhaps) as the cause, not an unreliable freeze generally...

I couldn't really determine much useful data to troubleshoot from the videos. It would be more helpful to see the mixer routing, what plugins are being used etc...

Edited July 20, 2022 by des99

[12bitcrunch]

Yep I’m a logic user of 20+ years also. 

The issues I’ve seen with freezing tracks online have all been easily discernible. Audio dropouts (or no audio), glitches etc.

There are no routing issues... regardless the unfrozen and frozen tracks are all going through the same routing so that shouldn’t make any difference?

I have a macro to bounce tracks in place which is reversible (using track alternatives and copy/paste/bypassing fx chain), so I’ll do it that way from now on. I can easily A/B without having to wait for Logic to render the freeze files every time.

No more freezing for me...

[des99]

14 minutes ago, 12bitcrunch said:

There are no routing issues... regardless the unfrozen and frozen tracks are all going through the same routing so that shouldn’t make any difference?

As I have no idea of your routings, all I'm doing is offering possible suggestions I can think - I can't actually look at your situation to identify any more specific issues. But yes, there are routing situations - for example, plugins taking in sidechains, plugins that rely on communicating with other plugins in the session (which won't be active when freezing), sometimes plugins with some kind of time-based modulations or generated arpeggiaters etc which sometimes don't work when freezing, and other situations that may affect this.

If you're interested in tracking down the culprit on this session, mute all the affected tracks except one, verify that freeze isn't working, then disable all the plugins on that track and keep checking the freeze results as you enable each in turn - this might identify at which point in the process the freeze is varying for you. You can then look at the plugin that's affected for a potential solution/workaround/bug report or at least an indication that that particular plugin/s seems to not freeze correctly (possibly a bug, or routing issue in the plugin).

You can also check the differences between source-only and pre-fader freezing.

Then you'd have some actual data as where the problem is occurring.

Let us know what you find out!

[12bitcrunch]

Can't identify where it's going wrong, have checked all individual channels, substituting and bypassing plugins. 90% it renders incorrectly but sometimes it has worked. Had a scenario where the track wasn't frozen but when I went to alter plugin parameters they were greyed out.

Perhaps a corrupted freeze files folder?

I would hesitate to say the project is corrupted, as deleting all other tracks in the project makes the freeze behaviour correct...

[des99]

8 minutes ago, 12bitcrunch said:

I would hesitate to say the project is corrupted, as deleting all other tracks in the project makes the freeze behaviour correct...

I would infer the opposite as you from that behaviour. It's quite often one or more tracks that have corrupted things, and removing them, or getting content off them, often fixes the corruption. So if one of those other tracks was causing project corruption, removing them fixes the issue, and causes the other artifacts to disappear. I'm not saying that *is* the problem, but there's usually method/experience in my troubleshooting approaches.

You just need to be systematic about tracking these things down. Are you saying that if you bypass *all* FX plugins, and freeze, you still get freeze issues? This is presumably on a software instrument track (as there would be nothing to freeze otherwise, just a raw audio track).

[12bitcrunch]

29 minutes ago, des99 said:

I would infer the opposite as you from that behaviour. It's quite often one or more tracks that have corrupted things, and removing them, or getting content off them, often fixes the corruption. So if one of those other tracks was causing project corruption, removing them fixes the issue, and causes the other artifacts to disappear. I'm not saying that *is* the problem, but there's usually method/experience in my troubleshooting approaches.

You just need to be systematic about tracking these things down. Are you saying that if you bypass *all* FX plugins, and freeze, you still get freeze issues? This is presumably on a software instrument track (as there would be nothing to freeze otherwise, just a raw audio track).

It’s on audio tracks. I can’t remove all plugins, as it’s the Haas delay plugin that’s not getting frozen always. It’s panning the audio track(s) hard left and right but with a delay.

[des99]

1 minute ago, 12bitcrunch said:

I can’t remove all plugins, as it’s the Haas delay plugin that’s not getting frozen always. It’s panning the audio track(s) hard left and right but with a delay.

So it's always this Haas plugin that's not freezing correctly, and only this is the thing causing the problem? Which plugin is it?

[12bitcrunch]

2 minutes ago, des99 said:

So it's always this Haas plugin that's not freezing correctly, and only this is the thing causing the problem? Which plugin is it?

No, sometimes if I mute one, two or all plugins before it the panning freezes correctly. Like I say it’s totally inconsistent. The plugin is Audec Haas 2.

The Haas plugin only accepts a stereo input so I have a passive instance of logic’s gain plugin before it in mono>stereo mode

 

[des99]

Ok, well it's difficult to go much further - if you say you've recreated this exact chain in a test project and it always freezes correctly, and you haven't had this issue in other projects, I'm inclined to think it's perhaps limited to this project only and is corruption-related (especially if deleting other tracks always fixes it).

You can of course choose to avoid freezing if you don't have confidence with it, but it's a rather severe loss imo. In this case, at least you can bounce and work around it. I guess just keep an eye on this in future projects, hopefully it won't happen again...

[12bitcrunch]

Yeh. Thanks for accompanying me through it!

Like I said, duplicating and bouncing track in place gives you the same effect, if a bit messier. 

[des99]

No problem - sorry we couldn't solve it, it's rather annoying I agree...

[solarama]

On 7/20/2022 at 3:50 AM, 12bitcrunch said:

So I went back into the session, confirmed the freezed files to sound different to un-freezed (unfrozen?).

Here's a screengrab of the frozen files viewed through Izotope Insight: https://www.dropbox.com/s/cqvbjvdpgqtewuq/frozen.mov?dl=0

And the unfrozen: https://www.dropbox.com/s/20kg9fwq6ccwtmp/unfrozen.mov?dl=0

Next step was to delete all the other tracks in the session. All different elements of the arrangement are in track-stacks btw.

Now the frozen files are true to the actual plugins inserted on the tracks.

Bit baffled here. Does cpu headroom affect freezing tracks?!

I've been having this same problem for a long time. Freezed tracks get corrupted regularly - stereo tracks suddenly can sound mono, sometimes it sounds as though one or more plugins isn't engaged, etc. I have to regularly unfreeze and freeze all of my tracks. There is no way to predict when a Freezed track will become corrupted, so this is a slippery problem. To verify this is happening, when you suspect your Freezed file is bad, do a Bounce, then Unfreeze and do another Bounce. They sound different!

[12bitcrunch]

9 minutes ago, solarama said:

I've been having this same problem for a long time. Freezed tracks get corrupted regularly - stereo tracks suddenly can sound mono, sometimes it sounds as though one or more plugins isn't engaged, etc. I have to regularly unfreeze and freeze all of my tracks. There is no way to predict when a Freezed track will become corrupted, so this is a slippery problem. To verify this is happening, when you suspect your Freezed file is bad, do a Bounce, then Unfreeze and do another Bounce. They sound different!

Yeh... the solution for me is to disregard the possibility of freezing tracks entirely. Now I bounce in place and keep the original if I need to revert. 

[des99]

3 hours ago, solarama said:

To verify this is happening, when you suspect your Freezed file is bad, do a Bounce, then Unfreeze and do another Bounce. They sound different!

I'm not sure what's happening in your specific case (I've never had an instance where a freeze file has been noticeably "wrong"), but be aware that a second freeze won't always sound identical to a first freeze, as many synths and FX plugins have random, or pseudo-random processes going on, free-running LFO's and other things, meaning that each pass will vary slightly, and so each freeze will vary slightly.

[solarama]

2 hours ago, des99 said:

I'm not sure what's happening in your specific case (I've never had an instance where a freeze file has been noticeably "wrong"), but be aware that a second freeze won't always sound identical to a first freeze, as many synths and FX plugins have random, or pseudo-random processes going on, free-running LFO's and other things, meaning that each pass will vary slightly, and so each freeze will vary slightly.

No, I'm speaking of huge changes in sound - e.g. two or more insert plugins seemingly disabled and, more often, the stereo field being compromised, in some cases to mono. I wish this were a repeatable bug but it happens at a seemingly random time (e.g. days later [opening/closing the project several times or more). 

[des99]

Yes, I get that - I said this general note to be aware of wasn't about your specific case in my post.

I haven't investigate your specific case - likely you have plugins that aren't working properly when Logic is freezing, or they require a sidechain input or other mixer routing which won't be active during freezing etc. Or some other intermittent bug.

Until you have some reproduceable case to go on, it's difficult to investigate that one.

[solarama]

12 hours ago, des99 said:

Yes, I get that - I said this general note to be aware of wasn't about your specific case in my post.

I haven't investigate your specific case - likely you have plugins that aren't working properly when Logic is freezing, or they require a sidechain input or other mixer routing which won't be active during freezing etc. Or some other intermittent bug.

Until you have some reproduceable case to go on, it's difficult to investigate that one.

I just had a frozen track shift in time to sound a bit late. The hi-hat from the Brooklyn kit, using the default Channel EQ and Compressor. I did a Bounce with the metronome and indeed it sounds late. Then I unfroze and it sounded fine again (and I did a Bounce of that too). This problem is intermittent and can take a long time to happen; often times I won't notice something is wrong if that track is low in the mix. Can you recommend a procedure to try to nail this down? e.g. create a new project, load a software instrument, open and close it 10 times, checking each time for any corruption...?

[des99]

I'd probably wait until a track freeze sounds significantly wrong, then locate that freeze file and make a copy of it. Then re-freeze the track, verify it sounds good, and make a copy of that known good freeze file.

Then I'd open both in an audio editor, and compare. If the first freeze file is not noticeably different from the second, then it's not the file itself, or the freeze process that's messing up, it's probably some internal project state or corruption on that track that's causing the problem.

If the first file *does* sound bad/wrong etc, then the problem is in the freeze process itself - but this seems unlikely as I think people are reporting the freeze files are initially good (indicating the freeze process was fine) but at some point down the line starts to sound bad (the file itself won't have changed if it hasn't been re-frozen). Unless you have some file/disk level corruption happening.

This would start to pin some cause on what you're experiencing.

[solarama]

6 hours ago, des99 said:

I'd probably wait until a track freeze sounds significantly wrong, then locate that freeze file and make a copy of it. Then re-freeze the track, verify it sounds good, and make a copy of that known good freeze file.

Then I'd open both in an audio editor, and compare. If the first freeze file is not noticeably different from the second, then it's not the file itself, or the freeze process that's messing up, it's probably some internal project state or corruption on that track that's causing the problem.

If the first file *does* sound bad/wrong etc, then the problem is in the freeze process itself - but this seems unlikely as I think people are reporting the freeze files are initially good (indicating the freeze process was fine) but at some point down the line starts to sound bad (the file itself won't have changed if it hasn't been re-frozen). Unless you have some file/disk level corruption happening.

This would start to pin some cause on what you're experiencing.

Whenever this problem has occurred, the initial Frozen track sounded fine. It is at some later time that this track (but not necessarily the Frozen file) sounds "wrong", which is the same issue as people have been reporting. As you said, this would imply that it's likely some internal project state or corruption on that track. Would you still suggest examining the Frozen files in this case (and could you please tell me how to locate Frozen files)? Otherwise, how can I try to pin down the cause of said track corruption? I appreciate your advice here!

[des99]

20 minutes ago, solarama said:

Whenever this problem has occurred, the initial Frozen track sounded fine. It is at some later time that this track (but not necessarily the Frozen file) sounds "wrong", which is the same issue as people have been reporting.

Yes, this is what I understood was happening, and what I was describing, with a way to verify this is the case.

21 minutes ago, solarama said:

Would you still suggest examining the Frozen files in this case (and could you please tell me how to locate Frozen files)?

I'm just giving you troubleshooting steps to gain hard information about what might be going on. Otherwise, all I can do is *guess*, which doesn't help that much...

Your freeze files will be in your project folder/package.

22 minutes ago, solarama said:

Otherwise, how can I try to pin down the cause of said track corruption?

Well, you're assuming track corruption is already the answer. I'm not sure we've got there yet, I would do the test I described to confirm that even when the freeze files sound "wrong", the file itself is good. Once and if that has been confirmed, troubleshooting can continue more in the project corruption direction. (Not that there are easy answers about what may cause projects corruption, unless a specific reproduceable case can be discovered to trigger the issue. That's not something that people don't experience this can do).

But check the freeze files first, so we can rule out one area of problems...

[Hast]

On 7/17/2022 at 8:45 PM, 12bitcrunch said:

The frozen tracks were totally different! Felt panned like 30 degrees instead of 90.

I'm having absolutely the same problem. Sometimes frozen tracks start sounding a way different comparing to the original. Like some of the plugins are just turned off.

It happens in different projects, on different tracks, with different plugins. And happens absolutely randomly. Sometimes it works fine, but latter becomes broken. Sometimes frozen track sounds OK, but once I'm freezing a completely different track afterwards, then one I froze before starting to sound wrong. And sometimes the same track with the same plugins is frozen perfectly fine. And I don't what to do, except for bouncing tracks in place (which is so annoying).

 

In my examples I don't use any side-chain if that matters.

My setup: OS Ventura, Mac Mini M1, Logic Pro 10.7.

 

Edited November 11, 2023 by Hast

[12bitcrunch]

Sorry to hear @Hast

I haven’t frozen a track since this happened to me. I just commit the track to audio now.

[rAC]

@Hast have you tried the troubleshooting steps @des99 posted?

[solarama]

Every session (almost), I unfreeze and then freeze every frozen track. This is how I avoid losing tons of time due to mixing with "false" or "corrupted tracks" (which would then require me to mix the song again, possibly from scratch). The other option would be to Export or Bounce the track and then reimport it into the session (or Bounce in place). However, if I do notice that a frozen track has "become corrupt" in the middle of a session, I will definitely follow the troubleshooting steps recommended by @des99 above. He gave very good advice. The problem might be something other than audio files being corrupted. But this is indeed a real problem that I've struggled with for years, having lost lots of time mixing with "incorrect tracks".

Edited November 13, 2023 by solarama