A few tips I found useful and would like to return to next time I enter the Composition Room.
- ‘DON’T ever send signal to multiple channels at equal level
One guaranteed way to ruin your surround mix is to send signals to multiple channels – especially adjacent channels such as the center, front left, and front right channels – at equal level. Doing so will almost always result in some frequency components cancelling out, resulting in comb filtering and a very evident “hole” in your mix, particularly as you move your head around.
If you’re going to send a signal to multiple channels, either do so at differing levels, or delay the signals slightly – optimally somewhere between 12 and 48 milliseconds. The human brain registers this as natural reflections, just like in a real space, and comb filtering will be at least minimized, if not completely eliminated.’ [1]
- ‘DO apply less compression and EQ
One of the big surprises to surround mix newbies is that you need way less compression and EQ. No longer are you having to slice and dice frequency bands and minimize the dynamic range in order to cram lots of elements into just two speakers. No longer do you have to work hard to give everything its own “space.” With six or more channels (and speakers) at your disposal, the music – and all of its components – has a lot more opportunity to breathe on its own, without you having to force the issue.
The converse is true as well: If you overcompress in surround, the overall mix becomes bland and difficult to listen to. You’ll find that the “glue” in surround mixes is a lot more subtle than it is when mixing in stereo.’
- If you have an instrument recorded in stereo, pan it hard left and right to the front speakers, then feed the signal to a stereo reverb and route the returns to the rear speakers. In a similar vein, route stereo drums to the front speakers and room mics to the rear speakers. Having dry signal come from two speakers and ambience coming from speakers in different locations can create a strong enveloping effect.
- In a 7.1 system, treat the “surround” speakers off to the sides as if they were an oversized pair of headphones. They represent the perfect place for you to hide that all-important “ear candy” in every mix.
[1] https://www.waves.com/mixing-in-surround-do-and-dont