90% of the time you'll be listening to the background music managing your underlings with about 10% of the time spent in battle, therefore you set the volume so it's comfortable 90% of the time.
when the battles start, the sound effects are at a MUCH louder volume with lots more bass , and i often find myself scrambling to turn down either the system volume via the keyboard or turning down the amplifier volume knob to keep things reasonable. this is with background music set to its loudest setting, (nf7s + audigy2 ZS + promedia ultra 5.1's)
IMHO what would be great would be a background music slider that went from 0 - 150% set in relation to the battle sound effects. or you could simply have two sliders: one for music and one for effects.