I have a stereo piano track and a vocal. What I’d like to do is to duck the mid signal of the piano (talking M/S kind of mid here) whenever the vocal is happening (the vocal is front and center), just as one more tool to increase vocal clarity. I know one way to do it is to have the vocal feed the side chain of a comp that is set to compress the M signal, and adjust it so there is 1 or 2 dB of gain reduction in the piano M signal whenever the vocal is feeding the side chain. I was reading that a drawback of that is that it may work the least when it is needed most, and vice versa. For example, when the voice is softest, we may want the most ducking of the piano M signal, but this is the time the gain reduction is actually the least.
Because of that, and because I don’t own a comp that does M/S and have a side chain, I tried another method:
I sent the piano to a group with the group’s first insert slot being a plug in that filtered out the side signal so only the mid was left (I used SPAN). In the 2nd slot I put a gate, and fed the gate’s side chain with the vocal. So, every time the vocal occurred, the gate opened and some of the piano M signal was passed; whenever there was no vocal, the gate was closed, and nothing was passed.
I then routed that to another group for the sole purpose of inverting phase of the piano’s mid signal, and then on to the master bus. So vocal caused cancellation of the piano’s mid signal, to a degree controlled by …
Well, it worked well in the end, but I hard a very hard time precisely controlling the amount of dB reduction in the M piano signal using any combination of the gate’s threshold and/or the send level of the vocal to the gate’s side chain. It was either a huge drop in the piano M signal volume, or no drop at all in my hands. In the end I found the best way to control that precisely/delicately was to adjust the post-gate gain feeding the phase reversal (I used the gain control in the pre-section of the “Phase Reverse Group” immediately after the gate). It wasn’t hard at all after that to dial in a 1 or 2 dB drop in the piano mid signal every time the vocal came in. It was fun to “check the ears” by putting another instance of SPAN on the master bus to show the piano M signal only, pulling the fader down on the vocal, and watching the piano M drop a dB or two every time the gate opened.
Anyone have any thoughts or suggestions on this? It occurred to me it would have been a whole lot easier just to automate the amount of mid compression on my Fairchild 670 so there was a dB or two of compression of the piano’s MID signal every time the vocal came in, but of course that wouldn’t get around the possible problem of having the least M signal piano gain reduction when the voice was the softest (i.e., when probably I’d want the most gain reduction).
(Also, just to confirm … the Cubase gate is sample accurate - no phasing when the parallel signal was run through a wide open gate, and complete nulling with phase reversal).
Thanks for any thoughts!