Ahh, one of the great quandries of our time. The shows do sound wretched and it is everyones fault. I would be happy to go back and forth on this for a while as there is so much to cover. To kick things off, I was not being flip when I said it was everyones fault. All parties contribute to the overall sound of the show. Here are the broad considerations. I would be happy to expound if interest prevails. In absolutely no particular order:
The Venues - Few concerts are held in appropriate venues. Arenas sound wretched but seat tons of people, clubs and bars are too small to have amplified bands in them, and those "acoutically perfect" theaters and concert halls were not built with amplified music in mind. In addition, the emphasis on ticket sales forces sound systems to be placed where they do not affect sightlines and people are often seated anywhere a chair will fit whether or not there has been consideration for sound coverage there.
The Promoters/Producers - No one wants to spend money on audio. Sound is a very competetively bid service whose costs have risen 10 fold in the past 20 years but rates have been held flat (once you compensate for inflation.) An emphasis on audio quality is a rare trait on but a few concerts especially if it costs money.
Engineers - Here is something I would love to dig into. The person mixing your show may have gotten their position in a variety of ways. Not all of these ways has to do with qualifications. I would love to see a Sound System Drivers Licsense program to keep hobbyists and unqualified people out from behind the consoles.
The Artist/Band - It is very likely that the engineer does not have a chance to mix a descent show. Between the monitor rig, whose levels are specified by the musicians and every guitar and bass amplifier/rig, there is no clean audio to be had on stage. As a matter of fact the first 10 - 20 rows of a show can be innundated with this wash of sound sources coming from stage. Do you know that a drummer who is sitting right on top of his drum set will have 2 monitor speakers and a subwoofer or even a full range PA speaker or 2 for his monitoring? Do you know what is coming out of these speakers??? The drum kit, very loud!! The drum riser can have SPL reading of up to 130 decibels from the drum kit and monitor systems. We are often times forces to trigger a sampler for at least the kick and snare sounds just to maintain any show at all. This is a trick I have used quite effectively. To their credit many of the Country acts have been leading the charge with in-ear monitoring and banishment of all the guitar/bass amps from the stage. I have a show coming up in October where we are doing just that. If I can not get a mix together for that show, I will have to surrender my Sound System Drivers Licsense.
Have you ever seen one of the engineers at a live show that spends most of or the whole show mixing on headphones. "I'll bet your mix sounds great in there buddy. Now how bout taking those off and mixing for the rest of us!"
I know this barely touches on you query but I though I would start with the broad issues. I have tons to unload about each so take your pick.
Respectfully,
Chris