For tests the starting repro state is as follows:
- One audio track slaving to one VCA track.
- Neither track has any automation written,
- Both tracks have automation Read and Write enabled.
- Inspector panel is open
- Set audio track to “global” for automation mode
- Open an automation lane to see what happens.
- If it helps, instantiate the test generator on the audio track to hear changes
Trim is either broken or behavior is questionably designed
Repro: (clear auto from previous if you haven’t yet)
- On the VCA, start writing automation at 01:00:00:00, moving down slowly to -20dB, hold for 5 seconds, move slowly back up to zero.
– The automation of the VCA is now reflected on the automation lane on the audio track.
– The fader of the audio track moves corresponding to this automation.
- Switch global automation to “trim” (remain in “touch”)
– VCA tracks fader drops down to the unity gain position that faders should occupy (in Nuendo) when in “Trim”
– Audio track fader does NOT move!
- On the VCA track, play back and once it has reached -20dB (which you were holding), do a pretty quick increase and let go of the fader. You should get a short peak at the beginning of this plateau.
– VCA fader remains at unity, which is how “Trim” usually works.
– Looking at the audio track you can see how the fader starts out at unity (good), and follows the “summed” automation perfectly (i.e. only the VCA automation, since that’s the only thing we’ve written so far) including that little spike.
On the audio track, play back, and once you are AFTER the peak you created, on this little plateau, wait a couple of seconds and then write another short “bump” on the audio track.
Deselect “Trim” on the global automation panel.
– VCA channel is as it was
----- The entire audio channel’s fader now STARTS at -20dB, NOT zero!
----- Before the first bump, it is roughly -40dB
----- Between the two bumps, level is slowly ramping upwards to -30dB right before bump #2
----- After the second bump, level does not drop back to where it was before, but to -28dB.
Combining auto again will make this easier to see.
In Pro Tools, when you work with tracks that belong to a VCA, enabling Trim mode on those audio tracks will reset the fader to unity gain after which it works as is intuitive.
It seems as if Nuendo reads “current” fader position as trim value, and since the “current” position was the previous automation (none) + VCA automation (-20dB at the beginning) that’s what it begins to write.
Work-around: Place an automation point at any point on the automation timeline before engaging trim mode, either manually or by writing automation.
This second “issue” may on second thought actually be as intended, and appropriate. Confirm if you feel like it, or ignore it…
Behavior is inconsistent depending on order of automation passes.
Make sure global automation is set to “Touch”.
On your audio track, start at 01:00:00:00 and write about 10 seconds automation. Write - specifically - a “narrow wiggly” line, what should look as essentially a sine wave of medium frequency and low amplitude after you’re done. The reason for exactly that type of automation is because by using a very different automation curve on the VCA track we will be able to clearly see if it works as it should.
On your VCA, start at 01:00:00:00 let it roll for a couple of seconds after pressing play, then over about 3 seconds lower fader to about -15, hold for a few seconds, and then slowly over 3 seconds raise to zero gain again.
— At this point, on your audio track, you will see the “summation” line resulting from adding the VCA automation to the track automation. It will be an equally “wiggly” line that follows your VCA automation line. In other words it’ll be wiggly along the original wiggly line for the first few sections and then drop, hold while still wiggling, then go back up.
On your VCA, range-select your automation and copy it. Go to 01:00:20:00 and paste that automation.
On your audio track, start playback at 01:00:15:00, and start writing your wiggly automation line again.
— At this point you should see a clear difference. In the first case, at 00 minutes 00 seconds, the wiggly SUM line drops according to your VCA automation. BUT, at the second spot, the sum line INCREASES!
— As you play back both spots, look at how the fader moves on your audio track;
------ After step 3 the fader wiggles up and down centered around zero first, then around -15dB, then back.
------ After step 5 the fader wiggles up and down around zero. Period. No other change.
- Switch to the mixer view and select “Combine VCA Automation”
— The difference seen above is now seen clearly with the sum line wiggling, but only around zero in the second instance.