Web Extras
American Lutherie #116 - Winter 2013

Page 6 - Beyond the Rule of 18: Intonation for the 21st Century

from their 2011 GAL Convention lecture by Gary Magliari and Don MacRostie

During the course of his investigation, Gary Magliari has run across some useful tips that he has graciously asked us to share with anyone that wants to try his method out.

  1. Hollowbody instruments with a fixed, glued-on bridge often bend a little when the strings are brought up to full tension. The distance between the nut and saddle can shorten about .020". The pre-tension and post-tension distances should be checked and appropriate adjustments made to the saddle slot position. It appears that this distance reduction occurs mostly in the body.
  2. If it becomes necessary to adjust intonation after completion, small adjustments can be performed entirely with saddle offsets. However, it would be better to split the required distance equally between the nut and saddle. For example, assume that the saddle needs to be reajusted .030" toward the tail of the guitar. It would be better to shift both the nut and saddle .015" towards the tail.
  3. Anyone that has attempted to take readings from fretted strings using an electronic or software-based tuner has undoubtedly had problems getting stable readings. Often these problems are worse at particular frequencies or neck positions. This is due to sympathetic resonances, standing waves, and other frequency-induced anomolies. Targeting a harmonic instead of the fundamental will often alleviate these issues.

Targeting the first overtone (2nd partial) has produced more accurate readings. As an example, suppose a reading of the A string (110 Hz) is desired. Set the tuner at A3 (220 Hz) even though the open A string will be plucked. The tuner will report a reading of the 220 Hz first overtone with much cleaner results. The inharmonicities are too small to be of concern.

Page 16 - Meet the Maker: William Eaton

by Tom Harper

Page 34 - The New England Luthiers’ OM Collaborative Build

by Don Boivin

Page 42 - Meet the Maker: Tom Cussen

by Rick Rubin