Will the truss rod fix this?
 

Played my Taylor 914 a couple of days ago and as usual when I finished put back in the humidified case. Pulled it out last night, clipped my Peterson tuner on the headstock and had to tune way way up to bring it up to pitch. Very unusual as this guitar rarely needs more than a minor tweak on a couple of strings to tune. It now sounds strident, a bit tinny and sounds grating, little bass and not as full as it normally sounds.

Fairly new to the acoustic world and I'm a little leery of playing with the truss rod but does this sound like all it will need? If so, loosen it or tighten?

What’s the room humidity in your place? What happened seems odd to me.
I would try leaving it out of the case for a few days.
See what happens.
BTW, to be honest, I’m not a fan of humidification unless it’s extremely dry as in below 35% on a consistent basis.

you just want to check / sight down the neck from the head stock to look for a back bow, which if it's severe enough would choke off notes a bit.

there's a few videos to explain
like this one: https://www.youtube.com/watch?v=XXaERG7omDY

One thing to be aware of, truss rod adjustments are usually 1/4 to 1/2 turn.

Have you looked at the back edge of the bridge to make sure it's not coming loose?

Those things even happen to the best instruments, when you least expect it.

If that appears to be okay, you might try thumping on the top in case a brace came loose, in which case you may also notice a more pronounced arch to the top.

I'm assuming this isn't a new strings issue, and there's always an outside chance that the neck joint needs snugging.

Best,
Howard Emerson

Did you check the neck relief by putting a capo on the first fret, holding the strings down on the frets where the neck meets the body, and seeing how much relief you have between the strings and the frets in the center of the neck?

Is your tuner set for standard guitar tuning (A 440)?

I can't see how the truss rod or humidity would have anything to do with your guitar suddenly being out of tune and sounding dramatically different.

I'd slack the strings and take it to a guitar tech.

Loss of bass and higher action makes me think that X braces are loose in the bridge area. Is the top bellying up?

I can't say if a truss rod tweak would help or not. There's just too many variables. But don't be afraid to give it a bit of a turn one way or another. You won't destroy anything if you don't force it. That said, it has not been my experience that the neck relief just goes out like that without any outside forces, I'm just saying don't be afraid of adjusting it.

Users turn to the truss rod because aside from changing strings and bridge pins, it’s all they’ve got. The truss rod’s setting it critical to the playability of the guitar, and adjusting it blindly in the hope of improving things is a fools errand. Once properly set, it is quite unlikely that it will need further attention between fret millings. In most cases that is every couple of years, if you’re a 3 hours a day player. Unless one has a clear concept of the truss rod’s function and the correct parameters of guitar set up, adjusting it it is best left to an accredited tech.

The chances of a sudden change of string tension being related to the truss rod are vanishing. Adjusting a truss rod make cents of difference, not semitones. Overnight humidity fluctuation can make a semi tone of difference, though it is very unusual. If the OP’s change was greater than that, it is likely that there is a structural failure. As mentioned by others, there are a variety of those that could make the difference.

Exactly what Bruce said. ^^^

I would follow Howard and Bruce's advice. This may be structural and require a tech.

I agree with rokdog49.
I am not a huge fan of humidifying a guitar. Too much will damage a guitar more than "drying out".

When a guitar is made the moisture in the wood is the least it will ever be.
From that point on it will only gain moisture, and "drying out" very little.

Moisture will cause havoc with braces and bridge glue as well.

I would suggest leave it out of the case, tune it and leave it for a day or so, and see if it stays in tune within a few of cents or so.
If not, take it to a qualified luthier. Just because a guitar store gives a guy the title of "tech" doesn't make him one.

Good luck hermano.

Ron

That is a nice guitar, if you know nothing about the truss rod then leave it alone, it could be a simple fix or complicated, it is such an unknown going by your description.

Did you buy it new, did you register your name with taylor as the owner, you would get a free checkup if you contacted them and gave them the details you supplied above

Taylors warranty is exceptional, i fixed a guitar last week 9 yrs old still under extended warranty as the owner registered the guitar with them when they bought it new

Steve

That is not true. Ask anyone who has ever had a top, back, sides or fingerboard crack. Ask anyone who has fret ends stick out. Ask any experienced woodworker about wood movement.

Wood is hygroscopic, like a sponge, and will absorb and desorb moisture in response to its environment. As it does so, it changes size and shape. This is well documented.

Extended periods in extremely high humidity can cause glue joint failure. 60 to 70% relative humidity is generally not high enough to cause permanent damage. That level of humidity can cause non-permanent expansion of the wooden materials resulting in raised action.

Very low humidities can also cause glue joint failures. Hence, one of the reasons that guitar makers recommend that one maintain instruments in a specified range of humidity, ideally usually from about 40 to 50%.

If you throw a wet towel over the guitar it may ruin it quite quickly, but if you put a couple of wet towels in the same room, assuming the humidity it spiking low, that is unlikely to do any damage.