Buzzing acoustic

dtaylorl · 02-08-2011, 11:12 PM

My friend's acoustic guitar started buzzing the other day. It's really well set up and sounded great until Friday night when the buzzing suddenly started, only a few hours after he had last played it. The buzz seems to happen if the strings are fretted and also if they are open. It's worst on the three high strings, but seems to effect the others as well. What should I be looking for to diagnose the problem? He though it might be the strings (they were many years old), but replacing them didn't solve the problem.

martinedwards · 02-09-2011, 05:25 AM

something loose.

tuner washers, or maybe the truss rod is loose in it's slot.

dtaylorl · 02-09-2011, 04:49 PM

After looking at it again I'm pretty sure the truss rod needs to be tightened. The buzz is definitely coming from the strings touching a higher fret. Tried to tighten the rod, but when I stuck the allen key in the slot it didn't reach. Is this normal? I don't really have any experience adjusting truss rods.

What really puzzles me is that it was working great, and then all of a sudden it was buzzing. Why would this happen so suddenly? The weather has been warm then cold then warm then cold here recently, so I'm wondering if humidity/temperature is a possibility... but that's pretty normal here and its never been a problem before.

Edit: I just discovered that the guitar has a "2-way" truss rod. What does this mean? Am I right in understanding that this means I need to turn it in the opposite direction?

jeepnstein · 02-09-2011, 07:25 PM

Humidity is your friend. Humidify before adjusting.

dtaylorl · 02-09-2011, 07:47 PM

I took it home to my house since I know my home is usually quite humid and also just put a wet sponge in the case in hopes of adding humidity. Turning the rod counter-clockwise did help a little bit, but there's still a lot of buzz. The truss rod is really hard to access - my longer set of allan keys just barely reaches it and they seem to be skipping in the socket so I didn't turn it very far... don't want to strip it. I'm also beginning to suspect that the old set of strings was a higher gauge. It buzzed with both sets, but the new ones seem worse. After its been humidified for a day or so I'll try it again and maybe throw the old strings back on and see how it is. Any other suggestions, especially regarding the truss rod, are appreciated.

martinedwards · 02-10-2011, 02:30 AM

a double acting truss rod means that it will add or remove back bow.

righty is still tighty, lefty is still loosey

and if the allen key is slipping then it's the wrong size.

Major Tom · 02-10-2011, 04:02 PM

If it is an import guitar, you will need to use metric allen wrenches. Some domestics may also use metrics these days.

dtaylorl · 02-10-2011, 09:17 PM

'Tis an import. I kind of think my keys are metric, but not sure. Even though we (Canada) are on the metric system, most things of that sort are usually the same as the states. I'll have to see if I can find another set somewhere. It feels like it must be really close to the right size, but just not quite.

FrankieTheKid · 02-25-2011, 09:34 AM

before you mess with anything you should find a setup guide for an acoustic guitar. most major manufacturers have them on their website.
as mentioned above, the truss rod will increase or decrease the bow in the neck.
attach a capo to the first fret and press the 6th string down on the last fret.
there sould be minimal clearance at the 8th fret. if the string touches any of the middle frets, the truss rod should be loosened to allow the neck to bow slightly. if it's cranked to tight the neck will arch the wrong direction and you'll get fret buzz.

another good suggestion (by you) was the difference in string gauge. obvious, but worth stating:
heavier gauge, more tension, more bow in the neck.
lighter gauge, less tension, neck will relax.

1. figure out what gauge strings you (or your friend in this case) prefer.
2. string it, tune it and check the neck bow and adjust the truss rod to .012" at the 8th fret using a automotive feeler gauge.
3. (probably the biggest nuisence) you'll have to adjust the saddle height so the strings sit approximately 3/32 to 1/8" off the 15th fret. this will involve loosening the strings, removing the saddle, adding or removing shims under the saddle, and re-tuning until it's right.
4. whatever gauge strings you set the guitar up with STICK WITH IT.

hope thes helps.