The "wall of sound" was an interesting example. When you see pictures from those days, every vocal mic was really two mics... one to sing into and another so the sound person could sum an inverted copy of the ambient to cancel as much of it as possible.Those old huge rigs look impressive but sound horrible. Back in the days you couldn't hear Jimi Hendrix singing if he plucked the strings at the same time and you certainly couldn't make out how great his tone was from all that deafening roaring. ...and I can't even imagine phase delays of Grateful Dead's "wall". I am quite glad we have come forward from those days because you can actually enjoy and hear the music -clearly- now.
Last time I saw a doom band performing with cranked full stacks I couldn't even hear anything but LOUD screeching noise and windows rattling. Every second of every song sounded the same. Distorted mess that is. They probably thought they sounded great just because they were louder than every other act that night. I know not to waste money to their concerts in the future.