You'll have seen all those buss channels on your mixer or DAW, over there to the right - like normal channels, but you can send and group all sorts of signals together. But are you really getting the most out of this part of the mixdown process? Read on, as we take a look at some tips for using busses to help your sounds...The most common use of a buss, especially in a modern DAW, is for FX sends. Put a reverb or delay on it, and use a send from your channel to that buss. This is a useful alternative to putting a reverb on your individual channels; as it offers you a lot more control. You can adjust the effect volume by changing the buss fader, rather than going into your plugin and fooling around with the wet/dry balance. You can even put effects on the effect - for instance, if you wanted to high-pass your reverb to avoid it sounding muddy, or put some stereo widening on it; this is easy to do on a buss channel, as it will only touch the effects. If you tried it on the original channel you'd alter your whole signal.
Using effect sends like this also enables you to put the exact same effect on several channels - useful for giving a coherent sound where everything sounds like it's coming from the same place.So, FX sends are definitely useful. But what about taking the whole output of your channel and bussing that? Well, just doing that with one channel won't be very interesting. But you can use this function to group things together, and that can be a powerful tool for enhancing your workflow. If you group all your drum tracks together in this way, then when you're trying to find the right balance for your mixdown, you can easily pull all your drums down by 2dB without having to individually adjust 20 or more channels. Similarly, if you feel your drums need more treble, you can do this at the group stage without having to add an EQ plug to every channel. This saves both time, and CPU power!
Once you've grouped your sounds together you can even - and this is where the modern DAW really comes into its own - send things to other busses. If you're not careful this can be a great recipe for confusion, but on the other hand can enable you to quickly and simply add effects to many sounds at once. Parallel compression is a classic example; we had an article on this some months back, so this isn't the place for a detailed explanation, but try an FX send to another buss, compress it heavily, and then mix it in quietly behind the original signal. You can try the same with distortion, valve emulation, and plenty more.
One useful psychological trick with busses is to help you look at your sounds afresh. When you have effects and plugins on your standard channels, you can get to thinking that because you have addressed a problem, it's solved. For instance, you might have used EQ to take some of the weight out of a guitar part, but not gone far enough. But you thought you'd sorted it. If you work at the buss stage (or, even better, bounce down stems from your busses and start a new mixdown with just 6 - 10 audio channels) you won't become distracted by the fact that you already EQ'd the guitar part, because you're not looking at the plugins you've already added. You'll be able to hear more clearly what needs to be done, and take action accordingly. Busses also enable you to get a bit more clever with sidechaining. A simple example might be if you wanted a pad to sidechain off both the kick and snare; you could send these two channels to a buss, which has no output. Then compress the pad off this buss. Or (and we're getting complex here) a useful technique for de-essing can be to send your vocal to a buss, and bandpass it savagely around the frequency you want to reduce; so you're left with nothing but the offending sounds. Then turn the output of that buss off, and you can simply sidechain your main vocal off this.
As you can see, busses can be a hugely useful tool in mixing efficiently and getting a good coherent sound out of your mixdown - even helping you look at the whole mix a little more holistically. But they can also be a very quick route to a complex and and confusing channel structure, so remember to keep things as simple and straightforward as you can manage! So, if you're ready, put on your thinking cap and get routing. It might just make the difference you needed to your mixdown...
