Probably the balance works on the mixer at the meters, but I bet when it hits the amps it goes mono.
I wouldn`t advise getting into rigs too much mate.
I accidentally got into it years ago, next thing you know I was putting on massive raves, and doing commercial installs.
Very very distracting, and possibly the ultimate audio gear porn.
Plus it means not only do I analyse the music I hear when at a club("man, they really killed the tops when mastering this tune"etc, in my head, but I`m also analysing the sound syste, ("useless twats have got the crossovers all wrong, and like bloody amateurs, it`s all bass and top and no mid")
Nightmare.