I have an EVGA Z68 mobo with Realtek ALC889 onboard audio. I have Z5500's hooked up to it via the analog connections and the stock speaker wire to all the speakers. I am using driver version 2.72 with my motherboard for the Realtek driver.
What happens occasionally is the front right speaker will be extremely quieter than the rest of them. The only "workaround" I've found was to go to Realtek Audio Control Panel, crank the balance to +10 right, max the volume on both PC and on the control pod, then do an audio test. It works ~33% of the time just by blasting them. Resetting the balance and volume returns the speakers volume to normal.
I have already verified that it is not the speaker (swapped front right and left, same thing), I have verified that it is not the driver (2.71 and 2.72 same thing), but what I DO know is that the front right clips on the subwoofer, when another speaker is plugged into that port, it also experiences this problem.
Could it be that the subwoofer is not supplying enough power to just that one set of jacks (front right)? Can I test it with a multimeter?