[microsound] speakers_unwanted noise

[John Hopkins]

>Radio interference is definitely an 'electrical' issue, but an 
>electrician wont be able to do anything. Any length of conductive 
>material has the ability to pick up radio waves.
>
>Try shortening the cable length, if possible.

using shielded (coaxial, for example) cable will eliminate much radio-propagation interference, also, multi-stranded (braided - which can be easily home-made) conventional copper cables will cancel certain sources.  You might also have cables cut to the exact length necessary to feed the speakers.  Likely it's not coming from the speaker cables or the speakers, though you say it didn't exist before -- I'd say it's a combination of a resonance between the amp and the length of the new speaker cables...

radio-frequency resonance -- picking up noise -- can be dealt with!

jh