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Hi All:

I was thinking about using a 630mm scale on a Hauser style classical, instead of the 650mm scale. What do folks think about moving the sound hole up a little so as to keep the bridge centered in the active area of the top? Thanks.

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GEO
perpetual beginner

I can't see why it would be a problem, nor do I see why it would be necessary. The only difference you are talking about is between 10 & 11 mm depending on changes in compensation. I doubt it would make a major difference in the sound of the instrument. The bridge would still be near the widest part of the lower bout. Moving the sound hole would require different placement of the TB's and would require longer fan braces, which would probably have more impact on the sound, and introduce other variables that would be more difficult to work out than moving the bridge 10mm. Much more change than that, though, and I think you'd have to re-design the insides of the instrument, and possibly the plantilla.

This, of course, is only my opinion, and does not reflect the opinions of other builders on this site, or the opinions of the management of OLF.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Moving the soundhole up, by itself, can make a surprising amount of difference in the pitch of the 'main air' resonance. As it gets closer to the upper edge the main air pitch tends to drop. You might want to enlarge it by a little (say add 1/8" diameter of a bit more). For more on this look up W.D.Allen's 'Basics of Air Resonances' in the GALs 'Big Red Book #1'.

Just so happens.....I have just installed a new top on a old 63 Goya 630 scale with a similar to Hauser style bracing system. The soundhole on the original top was 4" from 12th. fret to top of soundhole and diameter was 3 7/16.
I did not change the (centered) location of the soundhole on the new top....BUT, I altered the shape into something a bit different with the same opening area. Made for a difficult freehand rossette experience.
I'll post final pictures when I get'r done.
Kent Bailey

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