Combining VSTs into one output

What is the best way of mixing four input signals to one output signal? By how much should the input signals be attenuated in order to achieve the same theoretical output level as any one input level?

I have tried using logarithmic mathematics but the face that in Cubase there are 3 different ways to adjust the volume of any given VST (why did they have to do this!?!?!) this hasn’t worked out for me.

The following is what I have done so far:

Layered the VSTs into one track per midi controller.

Placed inserts (EQ, Maximizer and Reverb) onto this track (this sounds far better than doing it on a group channel, and is cleaner than doing it the original way: separate VST tracks with separate inserts). To mix the individual VSTs, as some need to be more present than others, I used the “Output Level” or “Level” under the mix tab.
N.B. If I ever need to combine VSTs from different plug-ins then group channeling will be the way forward.

Took the average range (dB) of a reliable sound from my old LIVE project (-18dB to -24dB, this is just how Cubase chooses to divide the ranges on the channel meters).

By adjusting the volume (range: infinity-12dB) on the macro page (homepage) for each VST track I made sure that the Stereo Out volume in the MixConsole screen was at least -24dB but not peaking above -18dB. For complicated sounds this also involved reducing the volume fader in the MixConsole room.

I have attached screenshots below to illustrate, and hopefully make clearer what it is that I am asking. I don’t work with recordings I purely play live using VSTs as my sound and use keyboard midi controllers.

Thanks in advance!
sound two - screenshot for mixing three signals into one.jpg
sound one - screenshot of mixconsole.jpg
sound one - screenshot for mixing three signals into one.jpg

For some reason I couldn’t add the fourth (and last) screenshot so here it is for you.

Also there is an interesting forum thread about this topic that I read before posting here about this, sadly they don’t seem to come to a conclusion but thought I’d offer it here too

Thank you all!
sound two - screenshot of mixconsole.jpg


I’m sorry, I’m not sure, I understand you completely. My understanding is:
Scenario 1: You have a single Instrument. If you play the Instrument, there is some Velocity.

Scenario 2: You have a layered Instrument. If you send exactly the same MIDI Notes as it is in scenario 1, how much should you reduce the Volume fader to get exactly the same Velocity?

Is this the question?

If yes, then there is no answer. It is always different. Lets imagine you have only 2 very simple exactly the same sine signals. Keep faders at the same levels (0dB) for next scenarios.
Scenario 1: You play just one “Instrument”, one sine. Lets say, the signal is +6dB at peaks. So the Velocity on the meters is +6dB.

Scenario 2: You play both “Instruments”, two si se, both of them start exactly at the same time, and they are exactly at the same phase. Both of them ar po +6dB. The result is +12dB. So, to get +6dB on the output, you should reduce both signals to +3dB.

Scenario 3: You play both “Instruments”, two si se, both of them start exactly at the same time, but they are exactly at the oposite phase. Both of them ar po +6dB. The result is 0dB. If you will increase both of them always by the same level, you will always get 0dB on the Output.

These were just 2 extrem cases. Imagine, you have many many phase shift cases in reality. And of course, you are not using sine signals.

So it always depends on the signals, you are mixing to.

And btw, there is one more factor, which is a human brain. If you set two different character signals to the same Volume (the peak will be at the same level, like 0dB), the human brain will “feel” and “interpret” it as a different Volume.

Lets imagine two signals:

  • Flute with very tiny silent (pianissimo) part.
  • Mix of the full Symphonic Orchestra in the fortissimo part.

If you set peak of both of them to the 0dB (no Compressor is used, to make it easier), the Flute signal would feel much louder. Because our brain expects a silent signal with this Instrument and color of the sound.

Martin is right, you can’t approach this as having some type of quasi-mathematical solution. Since (I assume) you are looking for a consistent sound your ear is really the final arbitrator. That said, you should look at the Loudness Meter in the Control Room since that is more indicative of how we hear sound.

From a practical perspective putting a compressor on the summed audio can help tame the variations. Maybe followed by a brickwall limiter. You might find that having several compressors in series each doing a modest amount of compression provides better results than one compressor set for greater compression.

Almost! If you replace velocity with amplitude then that is it exactly.