Wow, 9 years later and I'm having this same issue with the latest Apple bluetooth trackpad. I have a 2.1 logitech speaker system which isn't hooked up to my laptop that uses the trackpad on bluetooth. The woofer and nearest speaker are a good 3-4 feet from my trackpad. I use the speakers for music while I work as well as retro console gaming- so, again, not even hooked up to my laptop. Often I'll hear a feint "grinding" noise when I move my finger on my trackpad from my 2.1 speakers. I can't really move them much more- are there any other thoughts out there? I am considering (sometime) to get some new speakers - which MIGHT solve the issue, then again I'm hesitant to drop the $$ on better speakers only to have the same problem. 😵