Battery powered XO?

I'm planning to make a small active crossover, which will be used in a battery powered player I'm building.

Basically it will sum L&R then split the signal at 120Hz.

Anyway, i was wondering if I could somehow power this thing using 2 x 9v batteries one for each rail on the op amp.

The only thing I can think of is that the + and - voltaes may not always be equal, so would it be worth using something like a 7805 on each rail?