Finally met the dreadful "dead spot" thing.

[barber76]

Honeymoon with my first warmoth strat build came to abrupt end. Two days ago noticed, that 3rd string on 14th fret sustains ~ twice shorter, than the other strings. It starts to get worse around 12 fret, gets to worst at 14, and after 15 quickly gets better.

The worst thing, it doesn't seem to be fret leveling or action problem. The guitar was set up by a very good luthier, there's no buzz, no intonation issues, no tuning issues. All plays beautiful, and I didn't notice it for a while. Now, when I heard it, I can not un-hear it.
Luthier advice was to try to experiment with changing the mass of the headstock. Otherwise, this phenomenon, while known, doesn't have a guaranteed fix. It just happens sometimes.  :sad1:

 

[PhilHill]

I'd say your Luthier is probably right. Headstock size/mass/weight has been shown to have an effect on sustain. At the same time though, wood is a mysterious substance. Wood has it's own set of rules and does not care to vary from them. So, yes sometimes a piece of wood will have dead spots in certain areas and they may not be apparent right away. Sometimes they can suddenly show up as the wood ages. Or it can depend on ambient temp or humidity. And, unfortunately, there isn't much you can do about it. :sad1:

 

[Fat Pete]

Safe to assume you've tried a different string?

 

[barber76]

Safe to assume you've tried a different string?

Not yet, on the first set of 10-46 put on after the build completion. Will soon try 9's anyway, but w/e I managed to google, states this issue is not fixable by string change, even different gauge. Will see for myself soon.

 

[Cactus Jack]

I second the recommendation for new strings. During the assembly process and setup, I go through to packs easy.

Also, I'm sure the frets were assessed, and honestly, I have no idea if they would contribute to the problem, but I'd triple check them. I've purchased 8 brand new necks, and while they are all fantastic, in my opinion, they all required complete leveling and dressing. I could imagine the combo of a very high and very low fret right opposing one another could lead to fretting out. However, to really know you'd need to adjust the neck dead straight and measure, which would then require you to perform your setup again. Not a big deal for the extra peace of mind.

 

[barber76]

I could imagine the combo of a very high and very low fret right opposing one another could lead to fretting out. H

But then there will be a tuning issue, no? Problematic low fret (followed by a high one) will sound out of tune? One of reasons, why I believe it is just resonance oddity, is that there're no issues with tuning whatsoever. Oh, and also it is not a single fret that has an issue, more like a region on the fretboard from 12 to 15, with 14 just being especially bad.

 

[Cagey]

A high or low fret won't cause tuning issues per se, but it's possible for the imbalance between them to be so small as to cause a deadening of a string rather than a buzz. For example, when frets are leveled out perfectly and the neck set straight (no relief) so as to get super-low action, it'll often sound "dead" because the strings can't ring. With electrics, this is sometimes overcome by very high gain amplification, but on acoustics it's simply unacceptable.

Other times, a fret itself may not be seated well in the fretboard, so there's not a solid connection between the string/neck. The fret behaves sorta like a "cushion" and dampens string vibration. It's really the main argument for gluing in frets, as the glue tends to fill in the wood fibers and make it solid, not to hold in the fret as is sometimes thought.