the density and resonance of the woods combonation
effect the A.) frequency of vibration and the B.) amplitude of those vibrations. The resulting friction of the strings to the magnetic poles in the pickups create that sound you hear. (these days you have to take into effect the resistors and capacitors in the preamp that allow and block certian wavelengths from being heard or boosting whats heard)
the woods interacts by creating the amplitude and frequecy modulation for the pickups to "pick up"
[the lightwave pickups measure movement of the strings which is just a more precise way of doing it without the mags.]
of course I didnt pay all that much attention in physics
so I could just be blowing the hot air.
