What was unusual about Gary's set-up was that they were slightly behind him to his right and left and turned towards a center where he would be sitting. I thought, if he can't hear himself something was really wrong. Sowhen I got the usual complaint of TOO Loud, I moved my speakers to face each other behind me with about four feet between them. There isn't a lot of room on the stage so I couldn't get the angle Gary used but I sure got the effect.
Reece Anderson once tried a system of a secondary amplifier and small speakers on mike stands facing into his ears. I tried the system before I sent it to him and was certainly a new sound for me. He was to still use the main amp and speaker behind him for show sound but the speaketrs were so he could hear stereo and balance his playing accordingly.
This was the sound I heard then but at full stage volume as Gary was using. Since one of the facets of using one speaker out of phase as I do, the sound is, short of a better description, one big stereo swirl. The sound seems to be coming from everywhere and you are in the middle of it.
I will always give Gary credit for this change because it really was his own and I merely borrowed it. If you're listening up there, Gary: Thanks a million !!

Regards Paul