Playing the A string 9th fret tone is dead

[robj144]

Originally Posted by Willie Voltaire

Resonance issues are fairly common. On a lot of "ES" style semi-hollows, the 12th fret G (G string) is often dead, and on fretless basses the 5th fret C (G string) can also die off really quickly.

There is (or was) a product called a "FatFinger" that you mounted to the head of the guitar to increase headstock mass, and this often can remedy the dead note issue. It can also just move it to another note/fret, and thus isn't always the best fix.

Doesn't that just increase the sustain for an electric? I don't think it would change the Helmholtz resonance since that's mostly a function of geometry of the sound cavity and sound hole.

[rick-slo]

Don't know your vocal range, but for fun try humming into the sound hole of the guitar at various pitches and see which pitches resonant the guitar the most. Anything match the F#?

Originally Posted by robj144

Doesn't that just increase the sustain for an electric? I don't think it would change the Helmholtz resonance since that's mostly a function of geometry of the sound cavity and sound hole.

I've never tried one, but their claim is that it "works on electric and acoustic instruments. Adds tone, sustain, and overall tone balance. Helps tune out dead spots."

[redir]

F# is not a bad note to have such 'problems' on.

[Alan Carruth]

Of course the makers of any product are going to make any claims they think they can get away with. I suspect that the 'Fat Finger' may well help on some solid body guitars, but that's a different system from an acoustic. On a solid body the neck is the most flexible part, especially since it's usually longer than an acoustic neck, and often thinner too. Body modes where the neck bends can be significant sound sinks on a solid body guitar, and are especially so on basses, where the bridge is right down at the bottom end where it's moving too. Some of those modes on the few solid bodies I've checked are down in the range of string fundamentals, and so can affect the sound in one way or another. Adding mass to the head might make a difference.

On an acoustic the neck moves a lot less than the top. There's usually only one or two 'neck' modes that are in the range of string fundamentals: the lowest one is almost always much lower in pitch than the low E, and the next one up is much weaker, and quite variable in pitch. The only times I've seen the lowest, and most active, 'neck' mode of an acoustic make any difference in the sound were when it was much higher in pitch than is usual. That's rare enough on steel strings that I can't recall ever seeing one. Once in a while you get it on a Classical guitar, where the neck is shorter than on most steel strings, and fatter. I suspect it's more usual on Flamencos, with their light friction pegs. Adding mass to the head on an acoustic will drop the pitch of the lowest 'neck' mode, and it's already too low to make any difference in tone.

The 'main top' resonant mode on most acoustics is generally within a few semitones of the open G string pitch. The top moves a lot at that frequency, and can 'feed back' into the string vibration if the pitches match. This is the recipe for a 'wolf' note, and that's what the OP seems to have. Hence checking the top resonance is the first order of business, IMO.

[Woolbury]

You guys are taking this further than my limited guitar knowledge, but I recently had some work done on my Collings to help improve some thudding notes. He teamed the truss rod to eliminate some cupping, redressed a couple frets, and raised my action sever so slightly. Problems gone, it plays like a dream. Could any of these type solutions help your problem? Have a good guitar tech that can look at it for you?

[Arjan1961]

Well i called the store and i will send it back and let them look at it. Now that i know this issue it anoys me. None of my other guitars have this. And it is the new re-imagined D28 so it cost me enough and i want it working on all frets. I did compare it to a piano with one false note. But thanks all for your input, i learned a lot again and with that i am happy.