Speaking of "interference from powerful radio signals": Do you know that the one of the uBer Cable's design features is 100% RF shielding from plug to eartips? Is that the reason for it's legendary improvement is SQ?...possibly. It certainly is unique in that construction feature amongst all other 'upgrade' cables.
Interesting .... and how do they do that then? What kind of shielding provides 100% negation of RF frequencies? I don't think that the plastic that the units are made from would protect against RF interference, which might suggest that it is not RF shielding that improves the SQ.
I only know of one material that would stop absolutely any frequency from penetrating, and it would certainly be impractical. I mean all RF, that's a pretty broad spectrum.