Buzzz

[Wayne]

My J100 started buzzing on the last half dozen frets before the body, not above and not below. At least I think it started There is a slight chance I bought it that way a couple months and was just careless in checking it out-I dont go up the neck all that often. But I dont think it was doing this when I bought it. I cant see anything obvious, no lifted frets no major doglegs in the neck. I've been humidifying it religiously ever since I noticed it a few weeks ago. Any idea? I wont be able to get into the luthier for at least another week.

[Thermionik]

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Wayne - you changed strings perhaps, sounds like a relief problem, or maybe some iffy frets.

Be more specific in your description, folk can help you better.....

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[Wayne]

The problem grows worse from bass to treble. No buzz on the bass, very slight on the A, and very pronounced on the high E, and only in the last 6 frets before the body. There is no buzz on the body and there is non buzz low on the neck. I can see the strings practically lay on the upper frets when I fret it up there, so the problem is definitely relief in the neck or frets. I just cant see why it is happening. Frets and neck look good to me, but I'm no expert. This did start shortly after changing strings, but I went to mediums thinking that would solve it (it didnt) and am now back to the original type of strings it came with when I bought it used a few months ago. How can I be more specific?

[Thermionik]

When you look down the neck from the headstock, and up the neck from the bridge:

 

(1) Does the neck look flat, or does it curve slightly, and where and which way.

(2) Does the neck twist slightly (I'm thinking treble buzz -v- bass not buzzing.

(3) What is the action measured from each E-string to the 12th fret.

 

Any chance of a couple of piccies looking along the neck in both directions?

 

And has anyone done anything to the bridge that you know of, and what were/are the string gauges you used before the problem, after the problem manifested, and now.

 

That kinda 'more specific'.....

[Wayne]

I think it had Martin Marquis lights on it when I bought it. I put GHS medium PBs on it briefly, then replaced those after a week with Martin Marquis Lights. I kept the guitar out of its case until I realized how dry it was in the house, then started humidifying it. Action is ~1/16 on the low E and maybe slightly less on the high E. All I have is a ruler so its hard to be more accurate.

 

I cant get any pictures worth a damn. Viewing from the bridge it looks like the frets and/or fingerboard are slightly raised/more prominent on the body of the guitar. Viewing from the nut it looks like there is a slight rise in the fingerboard/frets at the body, with perhaps a slight scoop just before the body. Tough to say. My eyes arent that great up close. AFAIK there has been no bridge work, but the guitar is 6 years old and I've only had it since October. The RH in my house is about 28. I'm sure its closer to 40-50 in the case (Judging from my other guitar's case with built-in hygrometer), but like I said I only started humidifying a few weeks ago after I noticed the problem.

[Thermionik]

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You nailed it - neck needs a pro to look at it and advise, but it sounds like the neck is a roller-coaster ride rather than a nice smooth relief curve. And changes in humidity/temperature are best avoided, especially if sudden. Get it to a luthier and talk it through in person. Don't try anything on it yourself - no disrespect intended, I would take a neck of mine like that for a second opinion, if not actually getting the work done.

 

You have a low action combined with a string tension change at the same time as a change in environment. You may only be 'just' over the edge, and a good luthier may just pull you back 'afore ye falls clean off.....

 

Oh yeah, Wayne..... keep us informed and fingers crossed.

[brians356]

It is common and not really abnormal for there to be a slight hump in the fretboard near the neck/body junction. Your action is quite low for an acoustic - 1/16" = 4/64" under the low E is quite low. If you want an even scarier reading, slap a capo at the first fret and measure it again, which eliminates the string height at the nut as a variable and is considered the proper way to measure. If you could shim the saddle with somehting about 1/32" thick, that would raise the action to 5/64" and your buzz may just go away, leaving you with a reasonably low action. Before I did that I would make sure you have some neck relief: Holding the E string down at 1st and 12th fret, see that there is a slight gap above the 7th fret. Five to ten thousandths is reasonable (i.e. nearly the thickness of your high E string.) If there is zero gap, loosen the truss rod nut 1/4 turn (counterclockwise) and let it sit for a few hours and check it again.

 

Also, don't over-humidify the guitar! Many people go overboard. 47% relative humidity is optimum. Don't blast it with moisture unless you know for a fact it needs it (i.e. fret ends are poking out or top has sunk visibly.)

[Wayne]

The action is probably a little higher than I said. but it is low. It may be closer to 3/32. I'm mostly a fingerpicker and I like it low so it hasnt bothered me much (in fact I love it), though I've had to be real particular about capo placement to avoid buzzing (now I know why!). I play with a capo at 2 probably 90% of the time. I meant to shim the saddle last time I changed strings but was hoping that humidity would bring it back in line. I'm pretty sure the RH is no higher than 50-55% in the case.

 

I just did the 1-12 test and do have plenty of clearance at the 7th, probably more than the string thickness.

[brians356]

I doubt humidifying will bring it back to buzz free. How dry was the room you had it in, and how long was it in that environment?

 

Assuming the guitar stabilizes at near 47% for a few weeks (don't leave it at 55% forever!) and it still buzzes, you have a couple of choices:

 

1) Raise the saddle (new bone saddle is best for sound, shim is ok if you use hardwood or brass)

2) Have the frets leveled/dressed, and lower them an extra bit in the hump area.

[Wayne]

RH was probably in the 40s in my house till mid-November, by then it started dropping down to the high 20s RH where it is now. I've never had an RH problem with my other guitars but they were all fairly cheap. Are Gibsons primadonnas?

[brians356]

Gibsons are built with solid tops, sides, and backs, not laminates. And so like any premium guitar they are susceptible to cracking and top movement from changes in moisture content in the wood. Relative humidity in the 20s is very dry indeed. 47% is optimum, plus or minus 5% is nothing to be concerned about. Even really dry conditions in your house will take weeks to produce tell-tale signs in your guitar, as long as you avoid rapid changes in temperature. If you have an unheated room or closet in your house where the temperature stays 10 or 15 degrees cooler than your living space, that would be the best place to store the guitars. In such a cool space, any additional humidifying you might need will require a lot less introduced moisture.

[Thermionik]

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Wayne - please, unless you are 100% confident in your ability to both diagnose the problem accurately and apply the appropriate remedy, take it to a pro.

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[Wayne]

I'm not going to do a thing to it. I just wanted some opinions while I wait---I had an appt with the luthier last weekend but my car broke down. I have the appropriate amount of confidence in my ability, ie very little. Though I did build a banjo once. Not sure if that helps or not. :)

[Thermionik]

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I get the impression that building a banjo is probably cool, or at least bearably OK.....

 

.....just don't admit hereabouts to having played it :D