There is definitely a “sweet spot” in terms of proximity to the strings for a guitar or bass‘s pickup height. This was made abundantly clear to the inSync Tech Tip of the Day crew when we were at the PRS Experience 2010 open house at Paul Reed Smith Guitars. Guitarist extraordinaire David Grissom was playing two guitars for comparison at a “tone quest” shootout event. (A new PRS and a vintage 1958 Gibson Les Paul Standard.) He commented that he thought the PRS pickups were set too high; Paul Smith grabbed a screwdriver and dropped the pickups. The difference was immediately apparent; the guitar sounded excellent before, but with the pickups set slightly lower, the tone opened up, became rounder, and blossomed in a beautiful way.
The moral of the story: every guitar or bass has an optimal pickup height for producing the best tone. Take a few moments and play with the height of your guitar’s pickups, listening after each adjustment. Most manufacturers specify a standard “factory” height for the pickups. This makes a great starting point. Raise and lower each end of the pickup until the guitar springs to life!
Note: a handy tool for this is a ruler with 1/32″ or 1/64″ increments. This allows you to make note of the starting height so you can return to it later if you want, as well as for tracking which heights sound best.