Critical bug : Regions are not snapping to grid perfectly.

[cmscss]

It may be a visual bug but when you have a short looping clip, it goes out of time the more it loops - this is how I noticed it.

 

I actually thought it was a Logic/Tempest/Midi sync issue while recording (and wasted a day messing with it) until I noticed the loop point was ever so slightly out.

 

Now I cut files instead of dragging the end point, cutting is way more accurate - no timing issues.

[jwhitesides]

I know this hasn't been brought up in a while, but this bug is still happening in Logic Pro 10.4.8.

 

I have found something interesting though. The work-a-round is this: If you analyze a region with Smart Tempo, then try looping the region - it will loop perfectly at any tempo. While I'm not a huge fan of Smart Tempo, at least this saves the headache of having to go in region by region to clip the every growing out of sync bits out.

 

We still need Apple to fix this looping bug so that regions that are on the grid loop properly at any tempo without the use of Smart Tempo.

[DJFact50]

Confirmed again today... and thank you for posting this. Now I understand why I'm getting these ever so slightly out of phase sections in my tracks.

[jwhitesides]

This bug is still present in 10.6.1.

 

Been testing a setup for over the internet recording and have been attempting to figure out sync/clock issues. Initially thought it could be tied to the looping thing, but now believe it's literally a tempo issue in Logic.

 

That being typed... I did a looping exploration and found in 10.6.1 these are the tempos that Loop without issues:

 

224, 210, 200, 192, 180, 175, 168, 160, 150, 144, 135, 132, 128, 125, 120, 108, 100, 96, 90, 84, 80, 75, 72, 64, 60, 50, 48, 45, 40, 36, 32, 30, 25, 24, 20, 18, 16, 15, 12, 10, 9, 8, 6, 5

 

Any other tempo without a workaround as noted in an earlier post - will not loop perfectly. Can anyone see the math pattern? I can't.

 

This is specifically audio related. Sample rate does not matter. This only affects audio regions as MIDI regions now loop at perfect at any tempo.

[matronator]

Just encountered this bug when I was trying too loop a region on 93 BPM and found this thread.

 

That being typed... I did a looping exploration and found in 10.6.1 these are the tempos that Loop without issues:

 

224, 210, 200, 192, 180, 175, 168, 160, 150, 144, 135, 132, 128, 125, 120, 108, 100, 96, 90, 84, 80, 75, 72, 64, 60, 50, 48, 45, 40, 36, 32, 30, 25, 24, 20, 18, 16, 15, 12, 10, 9, 8, 6, 5

 

Any other tempo without a workaround as noted in an earlier post - will not loop perfectly. Can anyone see the math pattern? I can't.

 

At first I thought it might have something to do with prime numbers, because when I started checking the numbers in random order (excluding the obvious unfitting 5 at the end), most of them were directly preceded (by 1) by a prime number. But it was just a lucky coincidence that I got so many in a row fitting the theory, as I checked more numbers that didn't fit.

 

So I guess kinda pointless to even mention it, but I already had it halfway written before it was invalidated, so whatever. I was never good at math...

[Eriksimon]

 

That being typed... I did a looping exploration and found in 10.6.1 these are the tempos that Loop without issues:

 

224, 210, 200, 192, 180, 175, 168, 160, 150, 144, 135, 132, 128, 125, 120, 108, 100, 96, 90, 84, 80, 75, 72, 64, 60, 50, 48, 45, 40, 36, 32, 30, 25, 24, 20, 18, 16, 15, 12, 10, 9, 8, 6, 5

 

Any other tempo without a workaround as noted in an earlier post - will not loop perfectly. Can anyone see the math pattern? I can't.

 

I can sort of discern the makings of a pattern. You asked for this, it has been on my mind for two years now ( no it hasn't ).

 

The math "pattern" is multifaceted: no prime numbers in those BPM's, and no odd numbers other than multiples of 5. Divide 44,100 by those, and you get this series:

196,875 (7/8) - 210 (actually the square root of 44,100!) - 229.6875 - 245 - 252 - 262.5 - 275.625 - 294 - 306.25 - 326,33333 (326 1/3) - 334,090909(334 1/11)- 344.53125 (334 17/32) etcetera - so all integer fractions. I think the prime numbered BPM's are (part of) the problem, and probably some fractions that have a big denominator (see my much earlier post calculating with 44,100 and 199 BPM) - and I am pretty sure that series of "nonbuggy" BPM's will turn out differently at 48,000 Hz.

although...

It seems all those in the series are multiples of either 3 or 5, or powers of 2. As is 44.100, and also 48,000, both divisible by 5 and 3, so I'd think all those BPM's are also "OK" with 48,000 Hz.

A real mathematician (I am a fake one) may easily (or at least with more passion than I can muster right now) find a pattern. I stick to my earlier "rounding error in the samples" hypothesis. Some of those BPM's just don't end up in a whole number (of samples) for one bar (or multiple bars). It may well be that "fixing" this "bug" may interfere with Logics' engine (slow it down considerably). I don't think it is as ugly as Eric C. thinks it is though, as it can be quite easily worked around. in most cases it is more of an OCD thing than musically relevant, again, see my two year old post earlier in this topic

in factors, same series:

2x2x2x2x2x7, 2x3x5x7, 2x2x2x5x5, 2x2x2x2x2x2x3, 2x2x3x3x5, 5x5x7, 2x2x2x3x7, 2x2x2x2x2x5, 2x3x5x5, 2x2x2x2xx3x3, 3x3x3x5, 2x2x3x11, 2x2x2x2x2x2x2, 5x5x5, 2x2x2x3x5, 2x2x3x3x3, and I stop, because bored now, at 100: 2x2x5x5.

[extrememixing]

The rounding errors in the math are the problem. There is just no way to make all of the numbers come out even for all tempos and all subdivisions. It should be better with higher sample rates, but the problem does not ever go a way. Unless we get to the infinite resolution of light. But we're all dealing with the same laws of physics and others are able to make good music. If your sample loop is 3 samples off, music will survive.

 

Steve

[stratquebec]

The rounding errors in the math are the problem. There is just no way to make all of the numbers come out even for all tempos and all subdivisions. It should be better with higher sample rates, but the problem does not ever go a way.

 

Steve

So this « problem » should be inherent to every digital sequencer like Logic, Cubase, Pro tools and all. Isn’t it?