Questions about Neck and Bridge Pickups

[AngelOfDeath]

I know that the Neck pickup gives a mellower tone and the bridge p/u gives a brighter sound. I also know that all things being equal, the neck pickup would sound louder due to the fact the strings vibrate more above the neck pickup.

That being said, could anybody explain the theory on the brightness/darkness of tone depending on the pickup position? There's gotta be a scientific explanation. I'm quite curious about this.

Thanks.

[TonyT1000]

When you strum a guitar hard, there is more noticeable vibration taking place at the center of the string (which is closer to the neck pickup position) than on either end. That makes it much easier for a pickup to do its job. As a result, a much less senstive pickup is required at the neck position and a much more senstitive pickup is required at the bridge (hence the larger DC resistance readings for bridge pickups).

I would guess the the reduction of vibration at the end of the string would attenuate the low frequencies more than the high frequencies, resulting in a "mellower" or "darker" neck tone and a "more edgy" and "brighter" bridge tone.

Of course, the pickups can be voiced to compensate for these natural tendencies. For example, the Humbucker from Hell provides a very bright neck tone and the Tone Zone provides a darker and more bassy bridge tone.

[AngelOfDeath]

I don't know this for sure but for some reason, the vibrations of the string above the bridge produces more of the high harmonics in terms of strength. The vibration on the neck meanwhile has less strength in the upper harmonics of the sound. This seems to produce the mellower sound.

I just don't have the actual reason why.

[ibanez2005]

The harmonics are brighter as you go to the bridge because the string tension is greater there, thus the higher frequencies will ring out more cos string vibration is much smaller, the wider the area that the string vibrates, the more the low end will be pronouned. Buy an electronics book or read about how frequencies work, low frequencies travel further than higher ones because the waves travel a smaller distance.