Originally Posted by NoPro
It's that home security company, that monitors for break ins, fire etc. I hear they are now offering "HELP! ...I've fallen and can't get up!!!" type services now as well. For geezers like myself that is.
Seriously, it stands for "automatic double tracking".
I've also heard:
AutoMATED double tracking...and
artificial double tracking as well
Ken Townshend @ Abbey Road came up with it to simplify the tedious process of doubling vocal tracks.
Involves a 20-50ms delay, a VCO at a freq around 1 hz or under, with a depth of 40% or so, and usually no feedback.
Mix to taste w/ original signal, usually the dry out front.
Much more difficult in those days than with DAWs today, but theirs sounded about a million times better.
I still like real doubles myself, the ADT was a big part of at least Lennon's sound.