The tone of an instrument is heavily influenced by the position of the sensing bars or polepieces of the pickup along length of the string. The closer the pickup gets to the bridge, the brighter the tone, and vice versa.
The best reference and example is the positions of the Jazz Bass* pickups. These positions were chosen by Leo Fender when he developed the instrument and they are something to keep in mind if attempting a new instrument with different types of pickups or pickup positioning.
The centerline of the bridge or treble pickup of the Jazz Bass* is placed at 1/16th of the open scale length away from the intonation point of the ideal string. So, 34 divided by 16 gives 2-1/8" or 2.13 inches or 54 mm. Because there are no perfect strings and the string saddles must be "pulled back" (away from the nut) to compensate for their stiffness, the length from the G-string saddle to the center of the bridge pickup will be a little more than this.
The centerline of the neck or treble pickup of the Jazz Bass* is not so accurately placed and is approximately 6 inches or 152 mm from the G-string saddle. This yields the deeper tone of the J-Bass neck pickup.
By comparison to these two "standard" tonalities, one can understand the intermediate tone of the Music Man. Or the more aggressive tone of 2 pickups with closer spacing but the same bridge pickup position. Or many, many other variations and combinations of pickup position, pickup coil arrangement and pickup windings.
The "growl" of the J-Bass* bridge pickup is a very well known and loved. It comes from a very specific combination of these parameters. Over the years we have played many variations around this tune. It is a great tune.