Sound Mixing
One of the things I am passionate about and I do regularly is sound mixing, in particular church on a Sunday although it could relate to mixing sound anywhere. Unlike concerts that have professionals doing the sound, churches will normally use volunteers who aren’t necessarily trained or knowledgeable in what to do. One thing that really annoys me is when I walk into a service and the mixing isn’t good, especially when there are certain instruments or singers that you are unable to hear clearly.
Frequencies
Before you can understand how to mix sound you have to realise that sound can be broken up into frequencies and that certain instruments (including vocals) tend to use certain frequencies but not all of them.
A simple breakdown could look like:
0-20Hz Very Low – Too low to hear
20-60Hz Sub – Sound that would come out your subwoofers. The rumble of a bass drum would fit nicely here but not a lot else
60-250Hz Bass – Bass guitar fits here, need to make sure other instruments aren’t taking it over, ie. the keyboard. However, if there is no bass guitar then the keyboard might be appropriate to add bass to the mix
250-500Hz Lo-Mids – Usually a frequency you want to scoop out a little or avoid as it can make things sound muddy or boxy
500-2kHz Mids – This is where all the other instruments compete, along with the vocalists.
2-4Khz Hi-Mids – Some instruments and vocals may get up here but you need some of it otherwise
4-20Khs Highs – Mostly too high to hear and you may want to dampen some of this on vocals to remove harsh S’s (de-ess)
Equalisation
The way you deal with particular frequencies is through equalisation. It’s just a way of adjusting the difference between each frequency, either on an individual channel or on the mix as a whole. You can boost frequencies that you want and reduce those that you don’t. This is the most powerful tool a sound person has so it’s very important to learn about. You can add other effects and cool stuff but it will all be based on top of what you’ve done (or not done) with equalisation.
Mix with your Ears
It might seem obvious but you need to listen to what the whole mix sounds like and make adjustments from there. It’s easy to look visually at frequencies on a sound desk and make pretty shapes with the EQ but it’s meaningless if the sound is still terrible. Sometimes a good trick is to look away or position yourself somewhere else for a moment so you get a better idea of what it really sounds like.
