Radio? - Use a metal screen, and ground it, or at least connect to common wire.
Sound? - Put a pillow on it.
Electrical? - Use simple filters, like an RC filter (resistor, and capacitor).
Pulse driven power supplies are noisy by design. Perhaps you'd better start using analogue power supplies. They emit less, and are a bit more efficient.
Maybe I can build a custom one for you. See my web site:
Your statement that 'analoque power supplies' are more efficient is beside the truth. I agree that the RF noise generated by the switching power supplies is sometimes causing troubles, but there are sufficient means of damping, surpressing or removing the noise.
