Easy: Most studios owned a LOT of FX processors.
Most big mixing boards had 12 or more aux sends, and enough stereo returns and spare channels to accommodate the effects.
But if you still couldn't do it all, you tracked with effects like you described... or you could do a "bounce"... do a partial mix, and record the tracks with the special effects onto a spare tape track, and use that track as a base when you do the rest of the mix.
Bohemian Rhapsody was done with a LOT of bouncing... Mostly because there weren't enough tracks to record all the parts. (I think it was done on a 16 track machine if I'm remembering correctly...)
So they'd fill 14 tracks... bounce those off to 2... record 12 more, then bounce them (with the existing bounced tracks mixed it...) off to another 2. Any effects you wanted on the tracks had to be added at this point as well. You had to commit.
Sargent Pepper's was done that way too... that album was recorded on a pair of 4-track machines.
But it's actually very rare to use more than 2 or 3 different reverbs on a studio mix. You just send everything to one main one using an aux send, and use the other ones for special effects. Otherwise, the spacial imaging seems very, very strange.
I typically have a band reverb, a snare drum reverb, a vocal reverb, a "special" reverb (for strings or keys or choirs...) and maybe a delay or 2 (long and short) and perhaps a chorus or flange set up. And it's rare that I ever use any given 3 of those on any one mix.
Native XWA.Netter (Nutter?)
Last edited by edlib; 09-12-2012 at 12:22 AM.