"Be sure your foil hat has a good low impedance ground"

Thanks to Tweeker for this creative quote.

If the shield is not grounded, it will not act as a shield. It does, however, if wired incorrectly such that it becomes return ground conductor, act as a bigger antenna for the EMI.

But I guess some audiophools don't get the concept. But I guess you don't need science to make some audio stuff.

Shielded home speaker cables, heh heh.