This may be normal behaviour, although probably with polarity electrically inverted if it's a recording of something like a wind instrument. To say any more, we would need to know what the acoustic source was (e.g. type of instrument), the make and model of the microphone you used and of the audio interface or preamp+converter you used to capture the track. Was the microphone connected to the pre-amp via a standard commercial cable?

It would also be good to have a snippet (10 sec or so) of the raw track as recorded without any EQ, effects or other processing. You could post it here via the "Upload a file button" at the bottom right of the reply box.

sunbambino, post: 446775, member: 50321 wrote: no matter what I do in Logic X to balance the stereo field (by panning instruments) I don't seem to be able to correct a strange asymmetry where peaks (?) reach right to the limits on only one side of the audio file.

At the risk of hiting on the too obvious, but again you talk about panning in order to try to correct this. So I just wanted to be sure you are not considering the peaks at the bottom to be what goes to one side and the upper end going to the other side.
To simplify this at maximum, the wave drawing offered by audio softwares are representations of what an analog audio signal would do electricly. Positive at the top and negative at the bottom. What does that meen ? For exemple when the electric current goes to the top it pushes the speaker foward and when it goes to the bottom it pulls the speaker membrane toward the back.
The panning will only send the signal to a side or the other in the stereo field.
Now if i would be guessing why your wave drawing looks like this without analysing the file. I would say the mic of the instrument that peaks like that (possibly bass drum or snare) was on reverse polarity by error or was put on reverse to be in phase with other mics. But it could be a number of reasons other than this.

As Boswell said, a sample would be of help giving you a real answer and not guesses..

Thank you both, I will upload an small audio file later today, your expert observations much appreciated!

Of course (duh) I was making the assumption

pcrecord, post: 446777, member: 46460 wrote: considering the peaks at the bottom to be what goes to the on side and the upper end going to the other side.

So I've learned an important thing already.

Yes, what are we looking at there? That just looks like a mono signal (with a possible polarity issue).

Boswell, post: 446776, member: 29034 wrote: This may be normal behaviour, although probably with polarity electrically inverted if it's a recording of something like a wind instrument. To say any more, we would need to know what the acoustic source was (e.g. type of instrument), the make and model of the microphone you used and of the audio interface or preamp+converter you used to capture the track. Was the microphone connected to the pre-amp via a standard commercial cable?

It would also be good to have a snippet (10 sec or so) of the raw track as recorded without any EQ, effects or other processing. You could post it here via the "Upload a file button" at the bottom right of the reply box.

Yep, looks like an acoustic instrument or at least something with real motion, e.g. an electric bass. Another way to get something like that is with a bias offset but since the "short" side of the wave doesn't look clipped that seems unlikely.

In the end I sorted this by working out which track in the stereo mix was causing the 'problem', doing bounces with most likely offenders muted till I had the culprit, which was the main drum part. Then I excluded fx on that track till it became clear that a particular compressor was the cause. Replacing that plug with another I ended up with a file which showed none of that polarity issue. All good. (Except I have no idea why that compressor should have acted that way, I normally use all the time without probs...)

Thanks sincerely to all.

I'd like to know the name of compressor plugin was causing the polarity reverse. It's gonna be a valuable information for future reference ;)

I doubt the compressor was causing any polarity inversion. More likely it was inherent in the source or a result of the mic or cable. If the attack is set just right it could allow the initial transient through while attenuating the second half of the cycle.