Drop a stereo track into the "program" track.
The send (bus 1+2) from the "program" track returns up "Aux ø" where the left and right channels are panned to the center (-3.5db to compensate) and flipped out of phase using the trim plug.
This cancels anything that is panned up the middle and allows you to get an idea of reverb length,texture, predelays etc. It's also surprising what other things pop out when they are not masked by the main elements that are usually up the middle.
It's also useful when the client insists they want that "dry" steely dan sound and you can't convince them that there is actually a med/long reverb there but it's just not that loud.
Cheers, Bolla
Works like a charm!