The correct placement of the banjo bridge can be determined by measuring the distance to the bridge from the 12th fret of the banjo. The proper position of the banjo bridge is when the 12th fret is halfway between the nut and the bridge. Once properly positioned, the banjo bridge can be fine-tuned by moving it slightly forward or back until the desired tone is achieved. The positioning is crucial to the proper tuning, intonation and playability of the banjo. The bridge is not secured in any manner other than by the stress of the banjo strings.
In order to properly position the banjo bridge, the strings must be loosened to allow the bridge to be moved around on the face of the banjo. Once loosened, a measuring stick can be used to measure the distance from the nut to the exact center of the 12th fret. The measurement should be duly noted or a pencil mark can be placed on the stick at the exact location. The stick can then be used to begin at the center of the 12th fret and extended onto the face of the banjo and a pencil line placed on the face for reference.
The banjo bridge can then be placed on the face of the banjo at the pencil mark and the strings tightened. It is always best to tighten the strings slowly to pitch in small intervals. This avoids overstretching of the strings or placing excess pressure on the bridge or banjo face unevenly. Once tightened and tuned to the proper pitch, the fine tuning of the banjo bridge can be completed. This is accomplished by plucking each string, individually, in the open position and then while fretted at the 12th fret.
Compare the sound of the string when plucked in the open position against the same string plucked while fretted at the 12th fret. If the fretted note is sharp or higher than the open note, the banjo bridge is too close to the nut and should be slid slightly to the rear. If, on the other hand, the fretted note is flat or lower than the open note, the banjo bridge is too far from the nut and must be slid slightly closer to the neck. If it deemed necessary to move the banjo bridge, the adjustments should be very minimal and the process of comparing the open and fretted notes can be repeated until the notes are the same pitch.