troubleshooting Duplicate Tracks Not Identical [SOLVED]

[Bill Phillips]

I need help diagnosing duplicate tracks panned L/R that don't cancel when the phase of one is switched.

I've got duplicate acoustic guitar tracks panned L/R with identical FX. I was using the ME50 pedal output but decided that the pedal was introducing too much resonance and switched to the guitar DI which was routed to both my audio interface and the ME50 using a DI box. While I was using the ME50 track, I switched the phase switch on one of the tracks from time to time to be sure that all the FX were identical and the sound from the two tracks canceled.

I used the browser to bring the DI clip into the AG L track as Take2, slip edited the beginning to match the beginning of the ME50 track, checked it and bounced it to clips. Comping was not enabled, but to do the editing and move the clip, I used the edit and move tools because the smart tool didn't work in the take lane. Once I was happy with the AG L track, I duplicated the AG L track, deleted the existing AG R track, renamed the duplicate track AG R and moved the Pan from L to R. I then disabled all sends and PC, routed the outputs directly to the PreMaster Bus and routed the PreMaster bus to my interfaces Mains Out. I also added a Ozone Imager 2 plugin in the PreMaster FX Rack to display the combined output. As expected the L/R tracks combined in the middle and the Imager displayed a vertical line. But when I flipped the phase on one of the tracks, the Imager showed a horizontal line which was expected but what I heard was a thinner acoustic guitar panned hard L/R. I've checked everything I can think of but haven't found the problem.

I made two GIFs (A) shows the console view details and (B) shows the track view details. In (A) the routing should be clear, the PC is shown off and sends are off. In (B) the track peak markers line up, the clip names are shown and the take lanes are  shown. The Ozone Imager 2 is shown in bot views.

PS: Looking at the Imager displays. The one i (A) clearly shows the vertical line, the one in (B) doesn't but they are both vertical anytime the bot phase switches are off. Neither shows the horizontal line which is straight across the horizontal axis but that's what's displayed when on phase switch is on.

 

Edited August 30, 2021 by Bill Phillips
Details on Imager display.

[reginaldStjohn]

So , what are you expecting to hear?  If you sum them to mono in the pre-main output bus (Set the interveave button to mono) then they should cancel out and you should not hear anything. However, if you are playing them in stereo through your speakers then you will hear both sides come at you from your speakers but with one phase inverted. They will not cancel out in the air.

Also, be aware that if you run them through effects, especially stereo effects then the affected signal might not cancel since stereo effects can treat each channel separetely.

[Bill Phillips]

Thanks .

17 hours ago, reginaldStjohn said:

So , what are you expecting to hear? 

Nothing.

17 hours ago, reginaldStjohn said:

If you sum them to mono in the pre-main output bus (Set the interveave button to mono) then they should cancel out and you should not hear anything. However, if you are playing them in stereo through your speakers then you will hear both sides come at you from your speakers but with one phase inverted. They will not cancel out in the air.

Yes. All true. I hadn't thought of setting the Pre-Master interleave to mono which wouldn't work for me since all the buses and send FX need to be stereo in this mix.

Your interleave comment reminded me of what I'd done wrong. I want the duplicate tracks panned hard L/R. But, for the null test to make sure that they are identical, I need to pan them both back to the center. Once I did that just now, they cancel and I hear nothing meaning they are identical.

17 hours ago, reginaldStjohn said:

Also, be aware that if you run them through effects, especially stereo effects then the affected signal might not cancel since stereo effects can treat each channel separetely.

I want them to stay identical through the track FX. So I also make sure that the track FX are all mono and identical as well. That's working too. The send FX are stereo and do introduce some variation which is fine.

Thanks again.

Edited August 30, 2021 by Bill Phillips