Logic Pro 9 serious timing problem: help needed

peterlemer

Logician
Having recorded many vocal regions and at about 85% of the task completed, I found that many of the intervening regions were no longer in sync.

Timewise this project is a bit of mix, I took a commercial track and clocked it, to begin with, so the tempo map had some variations.

Then I gradually replaced elements, added sections, chords, riffs etc. and took the re-creation to a late part of the tempo map and set a fixed tempo.

Working solely in this fixed region, I applied some Melodyne here and there, and in one instance used the flex tool.

It is possible that I copied the vocal track with flex tool to several other vocal tracks - so making them all flex-prone. It is also possible that in slowing down sections for singer rehearsal I may have dropped 2 bpm without noting, and continued recording.

Whatever the reason, I am cleaning up the track and it's going fine, but I have this one very strange problem:

There's a short vocal region with no flex or melodyne working - just a plain vanilla region with a few blobs in audio view. I've even moved it to a brand new track. There are no plugins anywhere en route. Yet when I play this region the actual sound coming out doesn't even closely match the blobs - there's about 3 sec delay between visual blob and audio. I've never seen this before.

I've quit logic, re-started the mac, and the problem persists.

Any ideas? What's going on?
Can I refresh the drawing of the waveform? Is that the problem?

pete
 

forgetr

Logician
Select the region in question and check the delay parameter in the region inspector (top left corner or Options > Region Inspector Float). Are there any plugins on the track?
 

peterlemer

Logician
thanks for that, forgetr :) I have never noticed that float before and as it happens, I often visit the Inspector, and I no longer have to, as the float fits perfectly in my screen layout.

However, there is no delay on this naughty region, nor is there a plugin.

The region performed perfectly when I opened up this morning, but now it's late again.
I can't afford to lose confidence in my audio/visual connections.

I'll perform a Disk Warrior cleanup, and permissions reset.

pete
 

peterlemer

Logician
aha! again, thanks to forgetr I've taken a closer look at the region parameters, and there's a checkbox: "follow tempo" .

It's checked for this region, and when I uncheck it, the audio plays as displayed.

what is its function?

Looking at the manual, it says that when checked, a symbol appears in the media list entry for that region, but I have several regions in the list showing that icon, but they don't have a 'follow tempo' checkbox in the inspector.

Weird feeling to have a whole new playground where i don't know what the equipment does :-(

pete
 

forgetr

Logician
Ahhhh. That box will make your audio region do just that, follow the tempo map for your track. If you record an audio file at a certain tempo (or import one with tempo information), and then change the tempo of the track, that box will allow you to force that region to play back at the new tempo. Basically, it ignores the tempo information embedded in that region/audio file.

Glad I could help. :-D
 

peterlemer

Logician
...Basically, it ignores the tempo information embedded in that region/audio file.

Glad I could help. :-D
So many aaahhhs! :) This must mean that any artefacts ( heaven forbid) that might be created with the timestretching algorithms, could be introduced when the region is obliged to conform with the new tempo.

When it's switched on, why would audio sound later than drawn, though?

eg.
1. I record a region at 90 bpm.
2. I change the song tempo to 100bpm
3. with the 'follow tempt' checked, I would expect that region to play back from the right start point, but at 100bpm.

I would still expect the audio to match the drawn waveform. But from this experience, I guess that it doesn't?

And why would some of my regions have this checkbox, while others don't?
And why does the checkbox default to 'on'?

pete
 

Eli

Logician
And why would some of my regions have this checkbox, while others don't?

pete
There's your answer right there. If some are regions are set to Follow Tempo and others are not, and you've changed the tempo since the original recording, this is going to screw up the timing of the content in some places and not others.

Admin: add "SOLVED" to the top of this thread!! :D
 

peterlemer

Logician
And why would some of my regions have this checkbox, while others don't?

pete
There's your answer right there. If some are regions are set to Follow Tempo and others are not, and you've changed the tempo since the original recording, this is going to screw up the timing of the content in some places and not others.
:D
I'd like to know how some regions get switched to set Follow Tempo. Knowing nothing about this feature, I certainly didn't. As before, my region list has some set on, and others off. And some regions don't even have the checkbox!

pete
 

peterlemer

Logician
further: looking at a song from the same stable - it has many MIDI and audio regions, and has a few slight tempo changes to track a source MP3.
Looking at the Media list, I see the little clock icon next to regions, but the Region Inspector shows no 'follow tempo' checkbox. What determines whether a checkbox appears?
What determines whether a clock symbol appears?

pete
 
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