Active Speakers picking up FM

[kd5ief]

I had a pair of Behringer B2031A active speakers that I recently sold to a guy here in town. He sent me an email and says that when he plugs them in at home, he is hearing an local broadcast FM station from the speakers. This happens even if just the power cable is connected (using the built in amps). I'm guessing that the FM signal is coming in on his power lines.

What kind of RF choke would be appropriate to get rid of this? I was looking at the mouser and digikey catalogs online but they have so many I was a bit overwhelmed.

I'd like to give him a recommendation for a specific part so he can order the choke and hopefully get rid of the FM in his speakers.

Those speakers use standard computer power cables. So another thing I was thinking is that he might try some better shielded power cables. Anyone know where to pick up a fairly inexpensive shielded computer-style power cable?

Any other ideas for eliminating the FM signal are welcome.

Thanks,

Zac