Conventional wisdom has it that the construction of neck joint of the instrument influences the sustain of the instrument. Neck through construction (for electric guitars and basses) is considered to offer the best sustain, followed by set neck (i.e. glued on) construction. Bolt-on necks are considered to offer the worst sustain. A recent experiment in this area suggests that this order may be backwards and that folks can't hear the difference in sustain based on neck joint type anyway.
Last updated: January 22, 2019
Although the connection between neck joint type and instrument sustain is usually mentioned in the context of solid body electric guitars, it is often mentioned when speaking of acoustic guitars as well. I could find no formal research on this subject at all - no instrumentation and measurement studies, no formal listening evaluations. A recent study[1] performed power analysis, spectrographic analysis, and listening evaluation on a series of purpose-built instruments. The study was based on only a small population of instruments but it was reasonably well controlled. The power analysis results suggest that the relationship between sustain and neck joint type is the reverse of the conventional wisdom on the subject. Longest sustain was associated with bolt-on necks and shortest sustain with neck through construction. The study also included listening evaluations of recordings of single notes. Subjects could not detect differences in sustain among neck through, set neck and bolt-on neck configurations.
Although limited in scope, this study does suggest that correlation between sustain and neck joint type may not be of practical significance.
1. Mottola, R.M. “Sustain and Electric Guitar Neck Joint Type”
American Lutherie #91, 2007, p. 52.