instead of being a cunt and calling you cheap I'll actually assess the situation.
Some speakers depending on their configuration can actually pick up radio signals, how to stop it is beyond me but it is possible and is usually what's going on here. Look up incidents like this strictly for your model of Logitech speakers and see if you can solve it, if you can't and they're stuck like this, return them and save up for a pair of Creative Inspire T12, had a pair of them for close to 3 years now and have dropped them more than a few times from a few feet and they still sound great.