Acoustics spill, or leakage from one instrument into another's mic, is many times thought of as undesirable, but it can and should be used to enhance the sounds instead of avoided. In this video we'll look at decreasing leakage and also using it to our advantage when it's there. Many who are inexperienced at recording are under the mistaken belief that during a tracking session with multiple instruments, every track recorded must contain only the instrument or source that mic was pointed at. That's usually not the case, as most tracks normally have at least some leakage, unless they're totally isolated.

Let's take a listen to the top snare mic from a drum kit. (music playing) Notice how you can hear the other drums in the background of the snare hits, if only faintly. This is perfectly acceptable in most drum recordings. Leakage can be used as a sort of glue between instruments in much the same way that instruments magnify one another in a live situation. If you're in a small room and leakage is inevitable, instead of trying to avoid leakage, great attention should be taken to the kind of leakage being recorded, rather than trying to eliminate it.

If you can't get major separation by putting amps and musicians in dedicated rooms when tracking, try keeping the players and their gears close together as possible. Not only will it help the players communicate, but the leakage will contain more direct sound than the room reflections, which will make it sound better. This might make track fixes clash with the original basic tracks, so it's best to have keeper tracks from all the instruments to get the desired effect. Of course, if you can completely isolate things like guitar and bass amps in another room, all the better.