Isolation and separation

Isolation and separation are the two ways we avoid or minimise sound from instruments bleeding into microphones that are being used to record other instruments. 

Isolation is the use of multiple rooms when recording multiple instruments/vocals at the same time, this allows you to get cleaner recordings which will benefit later on in the mixing stage of production. This causes problems however because when recording musicians like to be able to see each other so that they can communicate visually. this is why in many studios they have windows between rooms.

Separation would be what you use when you only have one room available. Having amps facing away from other microphones and having them on the opposite side of the room is a simple but effective method of this. Portable sound proofed screens are also effective if used correctly. Placing them between instruments will mean sound reaching the other instruments microphones will be reduced.

however when a band are recording they need to be able to hear each others instruments/vocals to help them stay in time and in tune. This means you have to use an auxiliary bus to send sound back to the artists (usually the red knobs on the mixer). The more aux sends you use on each channel strip the more you can fine tune what each artist hears. You also have to make sure your aux sends are pre fader so that you can create separate headphone mixs for the artists and still tweak your main mix on the mixer. Post fader auxs are usually used when you're putting an effect like a reverb or delay on the instrument. This is because a post fader auxs will mean the whole of the signal is being put through the effect unit You send the sounds back to the live room(s) using a patch bay by connecting the aux output to the live room(s) send. Once the sound is back in the intended live room output it from the stage box into a headphone amp, now when you plug headphones into the amp and set your levels the artist will be able to hear the other instruments that are being recorded. back in the control room you can now create a mix of what the artist needs to hear. eg the drummer would need more bass in his headphone mix than he would need vocals. to give them this simply turn up the aux send on the bass channel strip that you have allocated to the drummers headphone mix.