I've just acquired the KEF KHT2005 eggs+sub system, together with a Marantz SR7200. A few days in, the subwoofer's started quietly "whirring". It appears to be coming from the speaker, whenever it's turned on (and not in standby). It's about the same volume as my Sony DVD player's transport playing - so only noticeable in near silence. The noise is a mid-to-high frequency whine with a faint crackle or clicks, sounding a bit like the radio interference caused by computer equipment. However, disconnecting the inputs, moving the subwoofer, turning off all other equipment and adjusting the knobs on the back don't seem to affect it. Has anyone else had this?