Two things re: sound in the stadium.
1) the acoustics will be much better, making noise transfer from one end to the other improved markedly (the RBB will have a roof overhead to reflect the sound for starters); and
2) speaker systems can be time delayed so that they all play at one time, but it's not necessary in this scenario because the furthest any person would be from a speaker at the stadium would only be about 30 metres max, which means every seat in the stadium will get a similar noise level during music playback.
Both of these will improve the "connectedness" at games.
But the biggest factor will be whether we're playing well or not.