It’d be interesting to know if the theatre in question was using an industry sound scheme or what? Even back in the day no one in, say, a United Artists theatre, cold in any way manner shape or form mess with any element in the sound chain or placement of same. You may well have been listening to what the Sound Mixologist mixed. We music mixers take our mixes out into the real world and listen on functioning systems. If I mixed on only my system (Adam A7 and UAD Apollo) and put it out, the result would actually be absent in the highs and overall quieter and somewhat low and mid heavy. I mix a power pop tune on only the record monitor system and it has the Eq profile of a late 50’s Perry Como record! I myself have sat in a theatre wondering what the heck refrence the mixer had. Way too much dynamic range as well. To modern ears any more than 6 dB may be a bit much.
Before the show started there was one of those mini adverts about the sound and picture system they were using liquid something or other.
I am not exaggerating on the bad sound my wife noticed it immediately and she never pays attention to such. At times the speakers were distorting because they had it up so loud, my guess either the system has been damaged and the woofers and tweeters were blown and they turned off the amps to those or the crossover was damaged or someone just had fiddled with the settings and screwed it up and to get it loud enough the just cranked the mids up. Because if what I heard is supposed to be the sound they were shooting for someone needs beaten with a spiked ball bat.