Both of these posts are spot on. I have attended games in Ohio State and Wisconsin in the last year. Your location within the stadium is the biggest factor in hearing the band. At Ohio State I was high in the second deck and the band was on the exact opposite side of the stadium from me. But, because they were pointing at me, I could hear them very well. At Wisconsin, again high in the second deck but this time the band was down to my lower left. I could barely hear them. It wasn't their fault. I'm sure I would have heard them fine if they were pointed at me.
The biggest problem with our band isn't the halftime or pregame shows, it is the sunken and too-small pit they have to sit in during the game. It is difficult for anyone to hear them on the closed end of the stadium... and it ISN'T their fault. It was really bad last year. This year I have noticed they have added speakers on the field that point back to the closed and, and it seems to help a lot. I have also seen them 'point' to either side when playing, on occasion. That has helped too.
Another issue I have is it seems like the programs like Michigan, Ohio State, USC, etc. understand how to set up for TV coverage. When watching a game on TV that is played at their stadiums, you can hear their bands PERFECTLY and it really adds to their 'branding' for their entire gameday production... and how it plays on TV. It used to drive me nuts in the Metrodome when you watched a game on TV and you could barely hear the rouser or what the band was playing, and when you did hear it, it sounded strange because it seemed like the microphones were placed about two inches from the flute players or another section. The 'U' has one of the best, most recognized fight songs in the country and it would always sound strange on home televised dome games. I figured it would improve when the team moved to TCF. Unfortunately it hasn't. Some media expert needs to take lessons from Michigan so the rouser sounds 'normal' through the TV broadcasts.
Any/all of these problems are outside the immediate control of the band itself. I think they do a great job. Gameday wouldn't be the same without them.