Are there any commonsense rules around adjusting the mid and side levels of a track?

[Uncle Freddie]

Hi,

Are there any commonsense rules around adjusting the mid and side levels of a track?

I have a piano plugin that sounds good in stereo, but has so much out of phase information that when summed to mono, it drops in level noticeably. I want to make sure the piano can be heard in mono while not taking away too much of the lushness when in stereo.

What I have been doing: I have another plugin (Goodhertz Midside) that allows me to adjust the mid and side signals independently. For every +N dB added to the mid, I make the same -N dB decrease to the side.

I am still trying to zero in on the perfect value -- seems to be somewhere between 1.5 and 3dB -- but the important thing is that I have been keeping the change 1 to 1. But the actual math of decibels and frequencies and human hearing are funny things...

Am I attacking the problem in the best practice way? Or are there some non-obvious but commonsense rules I should be following? Like maybe for every dB I add to the mid, I should subtract -0.5dB from the side...

I know "use your ears" is the final directive. But I am looking for commonsense rules around this if there are any. Like the commonsense rule of aiming for a level of -18dBFS RMS on your individual tracks. You don't have to follow it, but other engineers (and listeners) appreciate when you do.

Thanks,
Fred

[Wonks]

Doing a 1:1 increase/decrease keeps your overall volumes fairly level, but a lot depends on how wide you want the piano to sound. This is the creative side of things, so there are no rules, and even if there were, they can be broken. If you simply push the sides out until you're happy, then you may need to bring the overall piano level down a bit to compensate, but you'll have got it sounding how you like.

The end result of just increasing the sides then bringing the overall level down again, is basically the same as upping the sides and bringing the middle down to keep the overall level fairly constant (different frequency ranges so no exact match), but only worrying about one parameter rather than two when playing with the width makes it easier to make decisions (well it does to me).

[RichardT]

Something I don’t know - others might - is whether altering the mid / sides balance will affect the frequency balance of the piano.

[Wonks]

As the mids are the lower frequencies and the sides the upper frequencies, then yes it will, but any frequency balance depends on how it's miked up, so there's no perfect balance and any 'natural' balance will depend where you stand/sit in relation to the piano, and the room it's in. Near/far all make a big difference, and sometimes you need a brighter sound if it's a dull piano, and vice versa. And if in a mix, then it might need to change between duller and brighter depending if it's a background or a lead instrument.

[Hugh Robjohns]

Something I don’t know - others might - is whether altering the mid / sides balance will affect the frequency balance of the piano.

That would depend on what spectral content is being carried in each signal, but in general the answer with most normal stereo material is no. Altering the M/S balance won't change the frequency balance significantly.

As for common sense rules, adding and subtracting complementary amounts from each channel will help to maintain a constant level in the decoded signal. Most stereo width controls do that automatically.

When it comes to virtual pianos, though, many are created to sound very spacious and simply don't work well In mono, and no amount of MS manipulation helps. Try different sample sets.