Paint for EMI or RFI treatment

Hi,

I would like ask folks here if anybody know about paint or paste, can put on speaker or interconnect cables.   This paint or paste has feature for EMI or RFI field noises treatment,  which improve SQ.   I know there is something exist but seems i cant find  it.

The reason im asking because even im using expensive cables (AQ Fire & Castle rock), still the sound im getting is: bright, up-forward, music instruments close each other... .   Something telling me there  is another problem  in my settings.

Thanks for all your help.