How much does volume matter when breaking in amps and cables?

True. What you are hearing is not break in. Maybe tweaking as the show goes on, crowds, changing speaker positioning, your ears adjusting to the environment etc. 

Only if you say so. 😛

Geoffkait you should not treat aberyclark with such distain for telling you the truth. Your ears are indeed having trouble adjusting to the environment.

Try this. Wear earplugs for about 3-4 hours straight. Pull the plugs out and listen to your system. With your ears halfway rested, your system waill sound much different than you are use to. Same if you wore no earlugs cutting the grass for two hours. Chances are, one is attending an audio show out of town. Maybe travel was noisy, airplane cabin pressure or city altitude. Hotels are generally busy and noisy. Most likely one’s ears have to adjust for something different. 

Hey, Doc, is this the guy you’re backing? You sure about that, Doc? Well, I hate to judge before all the facts are in but I wouldn’t get behind him 100%, if ya know what I mean.