Left-Handed Acoustic Guitars?

[Eric Knapp]

Hi, all.

My sister wants me to make a guitar for her left-handed husband. She loves guitar #4 that I just posted about yesterday and wonders if I could just reverse the strings. My instinct says that it would not a good idea as the braces should be reversed too. What is the wisdom on this? Would a new nut and saddle be good enough for a lightly played instrument? Or should I tell her I really should make a full left-handed guitar?

Thanks,

-Eric

[Alan Carruth]

With the bracing, IMO the fact of asymmetry has more effect than the direction. Acoustically there's no 'treble' or 'bass' side: the low pitches are produced by the whole lower bout working as a loud speaker, and in the high range the top breaks up into smaller vibrating areas that add up to produce the sound. These can vary quite a lot even with 'the same' bracing, and the energy from the strings will find them.

I've been using a symmetric top brace scheme (double X) on steel strings for a long time now, and getting better sound than I did with the usual asymmetric tone bars, but if you like the sound of the usual brace setup you can stick with your normal pattern. In a listening test comparing the two folks said that the symmetric top was more 'modern' and the asymmetric top more 'traditional'.

What you do need to reverse is the compensation for the nut and saddle, fret dots on the side, of course, and the pick guard. If there's a cutaway that has to be reversed as well. Naturally a 'wedge' body would be sloped in the other direction too.

[Eric Knapp]

Thanks, Alan.

That's great information on asymmetric versus symmetric bracing. I'm now searching the net for photos and drawings of double X bracings. I'd like to try it.

This guitar also has a side port and wouldn't lend itself to being reversed. I'm going to make a new one for him instead.

[Alan Carruth]

Here's a shot of the rough top and back bracing on one of my guitars. Sometimes it gets trimmed down a lot.

Alan

[Eric Knapp]

Here's a shot of the rough top and back bracing on one of my guitars. Sometimes it gets trimmed down a lot.

Alan

Thank you, Alan. That will be very helpful.

-Eric

[Bryan Bear]

Alan, it is hard to tell for sure from the picture but I assume the tone bars X joint is a half lap just like the main X. It looks like both joints may be capped with a thin spruce cap. Is that right or do you add some cloth later in the process?

Since the double X tone bars are basically tapered braces, do you have a feel for how that compares to standard (asymmetrical) scalloped bracing?

[Alan Carruth]

You're right on both counts about the lap joint and cap.

Until I started using the double-X I never had much luck getting scalloped bracing to 'tune' right using the Chladni method. It's simply too asymmetric. It turns out to work much better if you leave the treble side of the main X tall, without scalloping it, as Dana Bourgeois often does. I learned that when I tok a workshop with him on his 'tap' tuning method: Chladni tuning is just a 'tech' method of doing the same thing. At any rate, leaving the treble side of the X tall makes up in some part for the fact that the tone bars run parallel (more or less) and perpendicular to the treble leg of the X. If you try bending the top along the two diagonals you'll find that with fully scalloped bars it's much more flexible one way than the other, and that messes up the symmetry of the modes.

[Freeman Keller]

Lot of guitars have been converted to lefty by replacing the bridge, saddle, and nut. You can fill the saddle slot and reroute it or replace the whole bridge. Add marker dots to the other side of the neck, a new pickguard if you feel necessary

If I was building from scratch I would mirror the tone bars but frankly I don't think you will be able to tell any differrence.