I used to believe the above statement, especially since my set-neck (Greg Bennett CD3) and neck-through (ESP LTD MH-300) guitars have very good sustain (to my ears at least). However, I now doubt such beliefs.

Science says otherwise with some researchers even claiming that bolt-on necks have the best sustain. There’s even a test that shows a Fender Strat (with a bolt-on neck) has better sustain than a Gibson Les Paul (set neck).

And so, is it just placebo that we tend to perceive neck-thru and set neck joints having better sustain?

Why is this an important question for guitar enthusiasts? We want the best possible instruments at the lowest cost. Take note that set-neck and neck-thru jointed guitars are typically more expensive than ones with bolt-on joints. Links to articles and experiments regarding this can be seen below:

http://liutaiomottola.com/research/sustain.htm
http://www.cycfi.com/2013/11/sustain-myth-science/

Perhaps sustain is largely dependent on craftsmanship, no matter how cheap or expensive a guitar is. Maybe excellent craftsmanship would always equate to excellent sustain rather than the kind of wood or the kind of neck joint used.