Official Luthiers Forum!

Hello all,

Needing a little assistance, advice, troubleshooting, from the collective expertise at this forum.

I finished my first guitar a month or so ago. It has the usual first-guitar blemishes (the finishing job really lacks), but I can overlook the warts as I made it. Sound-wise, it's pretty nice. Big full sound.

Except for one problem. The high-e string is extremely bright. And by bright, I mean very bright. I've tried different string to no avail. It almost ruins the sound of the guitar because that string is so shrill.

I made a new nut, thinking it wasn't cut well, but it didn't make a difference either.

What can I check, adjust, that might alleviate the problem. I did make the saddle myself (compensated). Anyone else have this problem? Just wondering what it is a symptom off?

Much thanks!

My first guitar had too much treble, too. The first place I would look to is the bridge, if all else fails with set up, etc. I made mine out of ebony, and solved the problem by replacing it with a rosewood bridge. Until then, I didn't think there could be too much high end.

It could also be the physical shape of the bridge, but features usually end up dampening sound, not reinforcing it. Do you have a picture you can post?

Another approach would be to dampen the E with braces inside/under the top. My model of sound production says that the first string generates a ring of vibration, centered on the cross point of the X brace (assuming this is a steel string guitar) with a radius usually outside of the bridge wings. Try plucking the E and feeling for any hot spots of intense vibration on this imaginary ring. If you find one (or two--they may be symmetrical) try sticking a gob of modeling clay there to see if it helps. If it does, you could consider it just another "wart" , or you could add a peaked short brace or two under that spot for an unobtrusive fix.

Scott

[QUOTE=Scott van Linge] My first guitar had too much treble, too. The first place I would look to is the bridge, if all else fails with set up, etc. I made mine out of ebony, and solved the problem by replacing it with a rosewood bridge. Until then, I didn't think there could be too much high end.

It could also be the physical shape of the bridge, but features usually end up dampening sound, not reinforcing it. Do you have a picture you can post?

Another approach would be to dampen the E with braces inside/under the top. My model of sound production says that the first string generates a ring of vibration, centered on the cross point of the X brace (assuming this is a steel string guitar) with a radius usually outside of the bridge wings. Try plucking the E and feeling for any hot spots of intense vibration on this imaginary ring. If you find one (or two--they may be symmetrical) try sticking a gob of modeling clay there to see if it helps. If it does, you could consider it just another "wart" , or you could add a peaked short brace or two under that spot for an unobtrusive fix.

Scott[/QUOTE]

Scott,

Thanks for the help. The bridge is a rosewood bridge that I bought from John Hall (I believe he gets his from Martin). I did no modifications to the bridge.

I might try the modeling clay to see if can dampen some of the high frequencies generated by that string. Any thoughts or ideas where I might start?

Here is the best picture I could find at work. Should give you some idea of how the bridge looks.



Thanks,
Mark

Hi Mark,

Well, it can't be the bridge, so on to Plan B. In my first post, I described the ring that is likely generated on the top by the first string.

Practically speaking, the place to look for a hot spot would be to the sides of the bridge wings (most likely symmetrical, with one on each side, if your side/finger braces are also symmetrical in shape and position). Pluck the E, and feel with your fingertips (I use index and middle, laid gently flat) to the side of the bridge on the left, or bass side, simply because it has no pick guard. Work your way up, feeling between the sides and the srings, until you are up to the bottom of the soundhole.

If a hot spot happens to be over a side brace, reshaping it parabolically might help. More likely, it will be over an area not braced, and a short (maybe 3" long) brace with a peak in the middle about 3/4" high will give some dampening. Try one, then one on the other side if that helps, but not enough.

Of course, you could just glue the gob of clay inside, if it works on the outside. Internal warts.

I saw an article somewhere that said the brace should weigh as much as the clay, which makes sense, too.

Scott

Adding mass to the top will drop the pitches of whichever resonances happen to be active in that location. Adding stiffness, by gluing on a brace, will tend to raise them. The rule of thumb for this with things like fiddle plates, where you're thinning an area rather than a brace, is to remove 1/3 as much wood as the mass that had the effect you wanted on the frequency. It's a bit tricker with braces, and there's not real direct correspondance, but the method is about the same. BTW, use poster adhesive, such as 'BluTac' or 'FunTac', as these won't leak oil into the wood the way modeling clay will.