I just bought the Bowers and Wilkins MM-1 speakers for my MacBook Pro and Windows PC desktop. For some reason, when I turn off any music or other audio on the computer, I hear hissing or static (white noise) coming from the speakers when I plug them in via USB or RCA into either the MacBook Pro or my Windows PC. When I unplug the USB or RCA cables, I do not hear any hiss, which leads me to believe that the cables are unshielded or there is a problem with the speaker's audio circuitry. The static is audible when I place my ear up to the speakers. At night when there is no ambient noise, the static can be heard from where I sit. Given that the speakers are $500, I am pretty upset. I have only been using headphones for the last several years, I do not know if this static is typical. Shouldn't the speakers be dead silent when no audio signal is coming from the computer?