Freezing tracks not trustworthy (10.6.3)

[rAC]

@solarama what part of your setup changed before you started having the problem? What was your OS version and Logic version then? What are they now?

What sort of Mac do you have?

[solarama]

I don't know when it started because for a long time I thought I was imagining it or that I had made some mistake. I have a MacBook Pro, M1 Pro, 13.4. I may have noticed this problem on my previous MacBook Pro (mid-2012), but I'm not certain. Very very few people are having this issue, but I have faith that we'll get to the bottom of it if we're persistent. 

Edited November 13, 2023 by solarama

[solarama]

On 9/16/2022 at 9:59 AM, des99 said:

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

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.

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...

I just found a case of a Freeze file being incorrect. It's an audio track with 5 active plugins. One of those is a UAD amp simulation with lots of distortion, so when I noticed that it sounded clean/undistorted, it was obvious that something was wrong. I copied the Freeze file, and upon unfreezing the track, the amp simulation plugin was clearly working again.

The Freeze file sounded as though only the amp simulation was disabled. In order to see if this was the case, I made a Freeze file with just that plugin off. This sounded similar to the first Freeze file, but not exactly. Comparing the two Freeze files in Logic, they were not identical. I then tried disabling the other plugins individually and together to see if I could produce a Freeze file identical to the first one, but the results were the same (they sounded similar but looked different in the editor). But there was one feature that was interesting: the first Freeze file was delayed by about 12.5ms compared to each of the successive Freeze files I made. 

What do you recommend I try next?

[Hast]

8 hours ago, solarama said:

I just found a case of a Freeze file being incorrect. It's an audio track with 5 active plugins. One of those is a UAD amp simulation with lots of distortion, so when I noticed that it sounded clean/undistorted, it was obvious that something was wrong. I copied the Freeze file, and upon unfreezing the track, the amp simulation plugin was clearly working again.

The Freeze file sounded as though only the amp simulation was disabled. In order to see if this was the case, I made a Freeze file with just that plugin off. This sounded similar to the first Freeze file, but not exactly. Comparing the two Freeze files in Logic, they were not identical. I then tried disabling the other plugins individually and together to see if I could produce a Freeze file identical to the first one, but the results were the same (they sounded similar but looked different in the editor). But there was one feature that was interesting: the first Freeze file was delayed by about 12.5ms compared to each of the successive Freeze files I made. 

What do you recommend I try next?

This looks like an obvious Logic bug to me...
Are you using native UAD plugin or DSP?

Edited November 14, 2023 by Hast

[solarama]

1 hour ago, Hast said:

This looks like an obvious Logic bug to me...
Are you using native UAD plugin or DSP?

Using an Apollo interface. But I was experiencing this same Freeze bug long before I started using that; there's no relation there.

[wonshu]

My money is on UAD plugins... especially if they're processed on external DSP...

[solarama]

I noticed this Freeze bug before I started using any UAD plugins. In any case, the Freeze track sounded fine at first, and I don't see how any plugin could alter the Freeze file once it has been created.

Edited November 14, 2023 by solarama

[12bitcrunch]

I experienced it with a single plugin. Audec Haas. Panning was totally off in the frozen track 
 

 

[Hast]

UAD/DSP is irrelevant, I asked it just to collect more information in this thread. For me it happens even though I'm not using any UAD plugins or DSP. And it happens randomly for different plugins.

[solarama]

10 minutes ago, Hast said:

UAD/DSP is irrelevant, I asked it just to collect more information in this thread. For me it happens even though I'm not using any UAD plugins or DSP. And it happens randomly for different plugins.

Apologies for making that assumption! I've experienced this bug using Logic Pro stock plugins only (Channel EQ and Compressor).

Edited November 14, 2023 by solarama

[solarama]

I noticed a second track in my project with a broken Freeze file - it has the exact same plugins/settings. It's likely that it happened to both tracks at the same time, but I'm not certain of that because I worked on the project for a while (on other tracks) before unmuting these bad tracks and discovering this problem.

I have not unfrozen this bad track yet; if someone can suggest an experiment, I have this "exposed bug instance" to work with.

[Hast]

Is there a way to get any response from the actual developers regarding our problem though?

[solarama]

1 minute ago, Hast said:

Is there a way to get any response from the actual developers regarding our problem though?

The problem is that we don't have a reason to suspect the plugins (yet). Also, I've never heard of anyone else having this bug other than the few of us in this thread, so I doubt Apple will be willing to look into it without some convincing/repeatable diagnostics.

[Hast]

8 minutes ago, solarama said:

The problem is that we don't have a reason to suspect the plugins (yet). Also, I've never heard of anyone else having this bug other than the few of us in this thread, so I doubt Apple will be willing to look into it without some convincing/repeatable diagnostics.

I'll have to switch to cubase then...

[Hast]

This has just happened again. I had a completely working project with several frozen tracks. I've added a new track, mixed it into the song, it sounded fine. Then I decided to freeze that new track. After the freeze, that new track sounded OK. But instead, all my previously frozen tracks all became broken :DDDDD Come one, this is my last message here, I quit logic once I finish current project (if it's possible) after more then 5 years of using it. Sorry, guys.

[solarama]

5 hours ago, solarama said:

The problem is that we don't have a reason to suspect the plugins (yet). Also, I've never heard of anyone else having this bug other than the few of us in this thread, so I doubt Apple will be willing to look into it without some convincing/repeatable diagnostics.

The reason I don't think the plugins are to blame is the Freeze file was correct originally (thus the plugins have done their job). The plugins aren't able to then alter that file; I believe only Logic can do that, or the Mac system.

[solarama]

3 minutes ago, Hast said:

This has just happened again. I had a completely working project with several frozen tracks. I've added a new track, mixed it into the song, it sounded fine. Then I decided to freeze that new track. After the freeze, that new track sounded OK. But instead, all my previously frozen tracks all became broken :DDDDD Come one, this is my last message here, I quit logic once I finish current project (if it's possible) after more then 5 years of using it. Sorry, guys.

That's an interesting observation - that new Freeze seems to have caused your previous Freezes to go bad. 

Was there any change to your system/setup just before you first started having this problem?

[solarama]

We might have a clue here (but only if you haven't unfrozen those tracks [which causes the Freeze files to be deleted]). Would you please check the dates on the previous Freeze files - are they the same date as the new one? If so, then we know the problem is triggered by freezing other tracks. To check this, right click on the project file and choose Show Package Contents. 

Edited November 14, 2023 by solarama

[Hast]

17 minutes ago, solarama said:

We might have a clue here (but only if you haven't unfrozen those tracks [which causes the Freeze files to be deleted]). Would you please check the dates on the previous Freeze files - are they the same date as the new one? If so, then we know the problem is triggered by freezing other tracks. To check this, right click on the project file and choose Show Package Contents. 

Sorry, I had to re-freeze every single track in the project to make it work, so I don't already have a session where it reproduces.

 

Quote

That's an interesting observation - that new Freeze seems to have caused your previous Freezes to go bad. 

I mentioned this behavior in my initial message. I already had a situation when freezing one track corrupts a different track that I had frozen long before. That leads me to the conclusion that it's not plugins or FS problem, it's definitely a logic bug while playing back frozen files. But since "we have not enough evidence" or whatever - I can't really use this anymore.

Edited November 14, 2023 by Hast

[solarama]

Hold on! We have a very good clue here, if it can be reproduced. As soon as you notice a bad Freeze file again, check whether it now has the same date as the new Freeze file. If so, we'll at least know there's a correlation and feel confident that it's Logic overwriting other Freeze files when it makes a new Freeze file. We might be close to at least knowing the cause (but not necessarily have a fix, at least not right away).

I faced the same dilemma as you, but with a different issue (a Bounced file sounds different/worse than playing in realtime). Very few people experience this issue (but it's not just me). For this reason, I nearly changed to a different DAW, and I still might...

[Hast]

I'll try to reproduce it once I finish a project, just for fun.

[solarama]

Looking for more suggestions. I've had more Freeze files go bad, and checking them in the directory doesn't provide clues. I haven't found a correlation between freezing a track and corruption of a different track.

Edited November 16, 2023 by solarama

[solarama]

Has anyone ever noticed that a Freeze file sounds slightly different than the original? I believe I do sometimes. Very subtle.

[rAC]

3 hours ago, solarama said:

Has anyone ever noticed that a Freeze file sounds slightly different than the original? I believe I do sometimes. Very subtle.

You can check by seeing if they null. If they are the same they should.

[solarama]

1 hour ago, rAC said:

You can check by seeing if they null. If they are the same they should.

It passes the null test (two identical files, Freeze one track, Gain plugin on 2nd track with L and R phase checked, two tracks played simultaneously produces silence). Yes, I know. By the laws of nature, they *must* be identical. Yet I can hear a tiny difference when playing each track individually in realtime in Logic Pro; it's very subtle and one must compare a few times. It sounds as though there's a bit more high mids in the original file; qualitatively, Freeze track has less "realism/presence" and less depth in the spatial image. I encounter the same issue with Bounce: the final Bounced .wav file is missing some of the "sparkle/clarity" compared to playing the mix in realtime, yet when it's reimported, phased reversed and played along in realtime, it produces silence. It might be specifically in the way Logic plays that file/track, but that's only a guess. Export does the same thing. There are others who experience this with Bounce, but it's a small percentage. For what it's worth, there are a few youtube videos that compare the sound of Logic with other DAWs and one can hear a small difference in character (using the exact same file). But because it passes the null test, nearly everyone dismisses this observation, and I can understand that.

Edited November 19, 2023 by solarama

[solarama]

One more thing to add regarding a Bounced mix being degraded compared to playing in realtime: a friend described to me the following: if you play a Bounced mix in iTunes, it sounds worse. If you then reimport that into Logic, it sounds "half way in between" as far as quality. This is precisely what I've found. Despite it sounding worse/different, it nulls with the rest of the mix. This is not an imaginary problem. It's a real phenomenon, but nearly all audio big-hitters say that this isn't true, possibly because it's usually quite subtle. Sadly, my friend has come to accept this degraded Bounce mix down, saying, "Well, as long as the musical intent/message comes through..." I may create a new post about this (but I'm sure it won't be well received!). 🙂 

Edited November 25, 2023 by solarama

[polanoid]

On 11/19/2023 at 12:59 AM, solarama said:

It passes the null test (two identical files, Freeze one track, Gain plugin on 2nd track with L and R phase checked, two tracks played simultaneously produces silence).

This is an actual proof that the two audio streams are identical. So, sorry, but your mind is playing tricks on you here. To rule out possible errors while doing this: How exactly do you compare the frozen track and the non-frozen one? To be sure Logic doesn't do anything "bad" to the frozen track at some later stage before it reaches the output, you'd need to do the null test on Logic's output signal, with one file recorded only from the frozen track and one only from the unfrozen track, and compare those files, phase-inverted, afterwards. If these two files null out completely, they are identical and it is absolutely impossible that there is any difference between them.

[solarama]

32 minutes ago, polanoid said:

I reimport the Bounced file into the mix, phase invert it, then play it along with the tracks, and it's "silent" when I turn up the volume on my Apollo interface. I do believe Logic is doing something "bad" during playback. Playing this reimported Bounce file by itself in realtime in Logic, it sounds better than playing the Bounce using Finder's Quickview or Quicktime, but not as good as playing the mix itself in realtime. You'd like me to do a null text on which two signals? The Bounced file and what else?

Edited November 25, 2023 by solarama

[solarama]

3 hours ago, polanoid said:

This is an actual proof that the two audio streams are identical. So, sorry, but your mind is playing tricks on you here. To rule out possible errors while doing this: How exactly do you compare the frozen track and the non-frozen one? To be sure Logic doesn't do anything "bad" to the frozen track at some later stage before it reaches the output, you'd need to do the null test on Logic's output signal, with one file recorded only from the frozen track and one only from the unfrozen track, and compare those files, phase-inverted, afterwards. If these two files null out completely, they are identical and it is absolutely impossible that there is any difference between them.

Would you mind doing this test with me: import a music file into Logic and apply a Gain of 0dB and Bounce it to a new file - no other plugins. Then, send me a few files (4 of the original and 1 of the Bounced, or vice versa) without telling me which is which. Let's see if I can tell the difference. Anyone is welcome to send these files. I probably won't be able to tell you which is the original and which is the Bounce, but I think I'll be able to tell you which one is different from the others.

Edited November 25, 2023 by solarama

[polanoid]

2 minutes ago, solarama said:

Would you mind doing this test with me: import a music file into Logic and apply a Gain of 0dB and Bounce it to a new file - no other plugins. Then, send me a few files (4 of the original and 1 of the Bounced, or vice versa) without telling me which is which. Let's see if I can tell the difference.

Wait a minute, this thread is about freezing, not bouncing, isn’t it?