Acoustic Guitar Construction

All the guitars I played through the years tend to have preference for some notes and a dislike for others.
Sometimes it is subtle, sometimes obvious. I think it has to do with the definite proportions of the soundbox, others think that the fingerboardmaterial has a major influence. (My local luthier says rosewoods suffer less than ebony on this item).
My lastest guitar has quite a preference for the E on the 4th string. But I don't want to adress this. Leave the guitar for what it is.

Opinions? Ever played a guitar that rings on all spots?

Herman

I've never played one that rings on every note. Segovia once said that you can tell the 'character' of any guitar by playing all the strings from the 7th to the 12th frets, and that's what I do when I'm trying out a guitar. Usually, in that area, the A string will be much less resonant and hardly any sustain.

Herman, I know what you are talking about and I agree that I have the same experience, however, I don't know yet what to do about it.
Is it an intonation issue? Nut slots issue, angle of the headstock, break angle at the bridge, type of strings, size of strings, the way the guitar is braced, the type of wood used????....well you probably get the idea.
I think I have played a Martin drednaught in the past that I thought was almost perfect.

Well, I think it lies in the nature of the guitar. Think it as a loudspeaker. Ever seen a loudspeaker with a dead flat charasteristic? No, there is always a mass (conus, or in the guitar: the top) that has its own resonance frequency and its consequences. And there is little to do about that. Only build as light as possible.

But I agree Kevin, there are guitars that show only a bit of deviating notes, that get in the way.

Herman

Trevor Gore might say it is a resonance issue. If the top of the fully assembled and finished instrument resonates at the exact frequency of a given note, the string energy is "dumped" too fast - it passes through the instrument too quickly because of the "friendly" resonance and the ear hears this as "dead" and certainly not the same as (in balance with) the other notes. Gore advocates tuning the top so all its major resonances are in between the frequencies of the nearest notes (assuming the git is tuned accurately). In his repair work he has gone as far as altering the size of the sound hole to change the Helmholtz frequency of the box.

That A string is pesky. I have one of those myself and what I did was put a much thicker string there than a normal set of strings provided. It is as if I said to the instrument, "You like to pass the energy through without giving it its due? So see if you can pass this." It helps. I wound up using an A string that was almost as heavy as the low E.

String gage -- tension to me is a key factor. Of course an over simplification, but you must have just enough overall tension to get the sound board moving in response the slightest string movement. Siminoff explains this well in his "Luthier's Hand Book There's a basic problem if one expects every guitar to sound its best just because it is strung up with their favorite strings. Years ago I had a conversation with Bob Taylor regarding the need to make this match up. His advice changed a ho hum 814 into a spectacular instrument -- I simply had the wrong strings set/tension for that instrument.

Also, a guitar set up with perfect intonation is a quantum improvement even if the slightest correction were needed and made.

I agree with both John and Ken above and think of the problem a little like noise cancelling headphones http://electronics.howstuffworks.com/ga ... dphone.htm where the frequency of the note played is cancelled out by the frequency of the body/top response.

Bob