I currently use the Logitech Z-5500 Digital 5.1 Speaker System in my home office, which by all accounts is a pretty high-end system (maybe not for a true audiophile, but for an average joe like me they're great). I am trying to figure out what the best way would be to share a single input on this speaker system between two computers (a Mac Pro and an iMac). I am currently using a basic headphone splitter with two standard 3.5mm male-to-male stereo cables to perform the task, and for the most part it works just fine with one minor issue that is likely to prevent me from keeping things setup like this... There is a subtle, yet clearly audible humming noise coming out of the speakers. Aside from going out and buying the most expensive versions of the two pieces of hardware I listed in the previous paragraph, does anyone have any other suggestions on how I can eliminate this humming noise? Thanks!