Logic Pro 9 'Bounce Replace all tracks' + Parallel bussing Aux tracks = Phase problems!

Logic 9.1.3 (32bit) OSX 10.6.7

I am trying to use the bounce replace tracks function in Logic to print stems.
It all seems to work ok, except when I try to print my aux tracks which are being used for parallel drum compression.
The result is the (bounced) aux tracks are out of phase. The aux track being late.
This is my work flow.
1) Preferences:- set plug-in latency compensation for all
2) Mixer Window:- Create arrange tracks for selected aux channel strips. (the ones I want to bounce)
3) Arrange Window:- put a region on these aux tracks so bounce replace tracks works on these aux tracks.
4) Bounce Replace all tracks.
5) Major disappointment!

When I solo just the original (bounced) drums channel with the (bounced) aux drum group track, the aux drum group track in out of phase.

If I solo the original (bounced) drum channel with the (not bounced) aux drum group track then everything ok.

Conclusion: When bouncing aux tracks there is some latency.

Is there a fix to this? Seems very lame as parallel drum compression is a very common mix technique and there seems to be no way to print stems for it.



Im using an older version of Logic but the way I always do this is to use Freeze - that way you get a high quality version with one button push - you can then go into the freeze folder and copy the parts (you can also specify the bit rate/sample rate etc etc as far as I rememeber)

It used to be a complete nightmare creating stems in the old days - and it neednt be.

Reason+Record is fantastic for doing this - really easy - Im using that program more now simply because of certain features like that being so simple.


I have done this without any problems. Do you bounce including plugins, I haven't tried that so I wouldn't know what happens in that situation.
interestingly, I did some extensive null testing (phase inverting two 'similar' bounces) between various versions of some loops using different bounce methods of some of my songs.

The principle is if any of the various methods of bounces are the same (which some should be) , then when they are doubled with one version phase inverted, the result should cancel out to silence. (null test)
If they do not cancel out to silence the resulting sound will be the difference between the bounces.

I null tested between all these various methods of bouncing.
1) A regular bounce.
2) A bounce after I 'bounced and replaced all tracks' (latency compensation on)
3) A bounce after I 'bounced and replaced all tracks' (latency compensation off)
4) A bounce after I froze the tracks

None of the bounces null tested completely or even close.
Each resulted differently. I would of expected 1 2 and 4 to be the same.
Some resulted in Omnisphere Trillian differences
Some resulted in Vangard differences
Some resulted in the Izotope Shutter Edit diferences
Some resulted in some low reverb sound from an audio track
Some resulted in some glitchy drum beats...
All different

Conclusion; (whilst using 3rd part plug-ins)
Your mix is NOT the same if you mix your songs after making stems either as 'bounce all replace tracks' or "freeze files' (and I suspect 'bounce regions')
The best sounding mix is a regular bounce, with much better bass definition and dimension in the mix, probably due to phasing issues and that this is how you monitored and mixed it at reference to begin with.

Caution when printing down to stems, maybe use stem only as emergency backup file if you update your system and find a plug-in not working. This should be a major concern if you are printing stems to cross platform to let say ProTools or something else.



I have found that the best way to make stems. And by best I mean confirm on the stems as you go / fastest and most reliable in terms of timing is to solo the tracks for the particular stem you need, then bounce.

I use offline bouncing, and I don't think it takes much longer to do it this way then any of the bip methods. plus I really feel more secure in knowing what I want on the stem is there.

And most of the time I'm combining several parts or instruments into a single stem anyway.

All the results are in correct time when done this way. You'll also have the added benefit of not having to deal with a second track for your parallel compressed parts. Just make it part of the drum/s stem.
Yes Bobdemnaa, soloing and bouncing one by one is the way I have been doing for years, but taking too much time and difficulty to archive all my various mixes and remixes as I never like to commit.

Just seems just a waste of a potentially really good function (bounce replace all tracks) is it does not work, if if one is not on the case, putting you in a false sense of security and ruining all your mixes.