Logic Pro 9 multitrack drum alignment


okay, so I'm thinking there must be a simple way to do this but I'm missing it somehow..I was reading this article


specifically, the section with the heading "Align Tracks" which talks about pulling room mic tracks into alignment with the rest of the kit and then applying a sample-delay plugin, the purpose of which is to avoid artifacts during flex-time quantization. So by blowing up the view of the drum tracks in the arrange window it's easy to see how the room mics are slightly delayed compared to the close mics, and the article suggests opening the sample editor and removing that amount from the start of the left and right room mic tracks.

So, since you can't see the other tracks in the sample editor to visually line up the cut, I'm thinking that the way to do this would be to make a separate section-the length that I want to remove- by cutting the track in the arrange window, then open that bit in the sample editor to see how many samples long it is, write that number down, then undo the cut I've made, open the entire track up again in the sample editor, remove that number of samples from the top of the region, and then repeat on the other room mic. Problem is, because they are two separate tracks (from a Pro Tools session) I can't take the same number of samples from each one-apparently Logic looks for an appropriate spot to cut and while somewhat close, it can be a hundred samples off. So I guess I have to bounce the L & R room mics to a stereo track and do it that way. Even so it seems pretty convoluted.

The other, bigger issue is that the edit in the sample editor is a destructive edit, meaning that there is no possibility of trial-and-error, adjustment, etc...it's really easy to make a fatal error using this method. I was working on a copy of the project-I know better than that-and I know I could make copies of the room-mic files also, but it's a PITA to go through the process of importing the original file every time you do this and want to un-do it. So, I'd be grateful for suggestions from anyone who's dealt with this-thanks!
thanks, but I think the idea in the article was to align the room mics for the sake of not having artifacts when using flex time and then inserting a sample-delay plugin set to the number of samples removed from the room mic files, to compensate and get them back in the same phase relationship with the rest of the kit that they were originally. I'm not sure if your answer applies to this issue, or maybe I'm just not getting what you're saying.
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apparently Logic looks for an appropriate spot to cut and while somewhat close, it can be a hundred samples off

You may well have Snap to zero crossings active, thus the disparity in cutting the files.

the sample editor is a destructive edit, meaning that there is no possibility of trial-and-error

Even though the Sample Editor is a destructive process, there are multiple undo steps (exact number adjustable in preferences) so you can just do an undo.
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thanks, I will check the snap-to-zero thing. However, when I made the cut, I was warned that the change would be permanent and not un-doable. I've seen things like that in the sample editor before, although I have also usually been able to use "undo". The only reason I went through with it this time was that I was working on a safety copy of the project so there was no risk.
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Hey - who you gonna believe? Me or the software warning box? ;)

To be safe, try this on an unimportant file and see how many undos you get. I seem to remember getting away with quite few, dependent on your settings.
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okay, so I checked it out...in Audio preferences/sample editor I have 5 undo steps selected. I tried-in a test project-delecting a section of audio in the sample editor and was warned that the edit would be permanently deleted from the hard drive and not undo-able. But when I deleted it anyway, I found that I was able to un-do it.

(un-checking the "snap to zero crossings" box worked, btw)

now I just have to figure out if the process described in the article I referenced (of aligning the room mic tracks with the close mics for the purpose of flex-timing the drums-and then using a sample delay to get them back to where the originally were) makes a real difference in the quality of the flex-timed file/s. So far I haven't heard any problems from NOT doing it that way...
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I have flex time edited multi track drums a few times. But admittedly, they never involved room mics (my room isn't _that_ big). I have never had a problem with the sort of alignment problems the author is describing in that article. I've certainly never had any problems with the overheads, but they are of course no where near as far away as room mics would be.

The process he writes about does make sense. But I suspect it really would only be necessary if you are recording the drums in a decent sized room with the room mics a fair bit away from the kit. It does seem a slightly cumbersome process, but does make sense. So use your judgement. If you are not hearing a problem when you don't re-align them, then just leave them - at least thats' what I would do.
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Eli said:
If you are not hearing a problem when you don't re-align them, then just leave them

I have to agree. The timing issues may be insignificant. If it aint broke there's no need to fix it..... However, it may be an issue that only shows up in certain areas - lots of cymbals, for example.
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