— Doubling —
Sometimes a track doesn’t seem to have the presence it needs to stand out when mixed with other tracks. We’ve already established how duplicating that track will increase its loudness beyond the level that can be reached with a single gain stage. But when the volume is set right and it still sounds thin, then a different technique is required.
Doubling is when you take the track and duplicate it, but then slightly alter the other track, so they’re no longer identical; but still sound pretty much like they’re the same track. The earliest and most rudimentary form of doubling is stacking. This is usually done on vocals but has also been done on other things like guitar. Stacking is recording over one performance with the same exact part. The object is to get both to sound as similar as you can get them. The fact that both can never truly be the same is what makes stacking work. For years, this was the way it was always done! It was a painstaking task and one which required many hours of studio time and scared many musicians and vocalists away. Thanks to innovations from studios like the famous Abbey Road, there were some other methods of doubling developed which are much easier to contend with. An automatic double tracking system, which involved two separate models of tape machine and a variable speed control, allowed one recording to be turned into what sounded like two. Eventually this led way to an effect known as chorus. With automatic speed variance being controlled by an LFO, (low frequency oscillation), a silent and slow wave creates an oscillation back and forth. As this happens, the speed of the duplicate track is sped up and slowed down accordingly. Chorus effects can’t compare to stacking because both sound very different. But both are useful in different places.
Another form of doubling which is much simpler, is delay, which simply echoes the track back after the original plays. The timing of the echo and the number of times it echoes are factors that can dramatically change the way this sounds. Most engineers today are fond of dub delay which is the sound created by playing back the duplicate from a tape machine. Waves Audio has released a plugin called Reel ADT which was developed in partnership with Abbey Road Studios to simulate their original tape machine setup which was designed to make tracking easier for John Lennon.
Whether it’s delay or chorus, doubling uses the reinforcement of the original sound through duplication and, then, by slightly altering that sound, gives the feel of more than one instance of the original. Timing, pitch, speed, pan and other qualities are experimented with to make this sound as natural or as otherworldly as desired.
NOTE: SOMETIMES DELAY CAN BE PREFERABLE TO REVERB TO SIMULATE REFLECTION. WHEN SET CORRECTLY IT HAS THE ADVANTAGE OF OF SHORTER SUSTAIN WHICH CAN KEEP THE MIX CLEARER.