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View Full Version : How to modify kasha bracing system?



kimmylele
08-03-2012, 03:40 PM
I'd like to build kasha bracing system that I got plan from hanalima but it's for low G strings,
question is,

1.How can I modify if I'd like to place the sound hole to the center (original sound hole)

2.How to modify the 6th string bracing if I'd like to use high G string?

Thank you for your advance.

oudin
08-03-2012, 03:49 PM
I would move the sound hole to the center and use fewer braces. The bracing configuration does not effect the tone on a one-to-one ratio. It is subtle and indirect and there are about three times as many bracing patterns as there are luthiers. And while I have my preferences, it would seem that most of these variations work well.

mm stan
08-03-2012, 06:43 PM
I'd like to build kasha bracing system that I got plan from hanalima but it's for low G strings,
question is,

1.How can I modify if I'd like to place the sound hole to the center (original sound hole)

2.How to modify the 6th string bracing if I'd like to use high G string?

Thank you for your advance.

nice playing on you video Kimmy

kimmylele
08-04-2012, 06:13 AM
I would move the sound hole to the center and use fewer braces. The bracing configuration does not effect the tone on a one-to-one ratio. It is subtle and indirect and there are about three times as many bracing patterns as there are luthiers. And while I have my preferences, it would seem that most of these variations work well.


Thank you sir,
I'd try to build follow your advice first and adjust later for next batch.


nice playing on you video Kimmy

Thank you, :D

The Big Kahuna
08-04-2012, 06:53 AM
I have a daft question, but this would appear to be an appropriate place to ask it:

Has anyone ever experimented with alternatives to wood for bracing? Such as carbon-composites or ultra-light honeycomb materials? It seems to me that the holy grail of bracing is light weight combined with rigidity and strength. Surely there are much better alternatives to wood.

BlackBearUkes
08-04-2012, 02:42 PM
The bracing is only part of the overall picture. There are many today using carbon/balsa wood combinations and the honeycomb composites in there bracing systems, mostly in the classical guitar world. Greg Smallman being the most successful builder of classical guitars, who start doing this stuff in the late 80's. There are however some compromises along the way, the biggest being the kind of sound some of these instruments deliver. To my ear, some of these guitars have a metallic edge to the sound which I do not like much. With the added strength of the carbon fiber and thinner tops, the sound changes. Some like it, some don't. After years of listening to classical guitar, I prefer a woody, clear strong Spanish sound.

The ukulele has had a few builders working with some of these same ideas, but with a small body instrument, I personally don't hear any advantage for all the extra work involved. This could be a lengthy discussion because of all the different ideas used. Excellent quality Sitka spruce bracing is very hard to beat when it comes to stiffness, weight, longevity, and availability. And remember this, the braces do not make the sound, they only help to regulate and support the top wood which does make the sound. All things being equal in weight and size when carbon fiber or spruce bracing is used, for me spruce wins.

Rick Turner
08-05-2012, 06:58 AM
I would ask a simple question, "Why?" The impedance matching concept of the Kasha system has been pretty much debunked. This idea that different parts of the top can be coupled in frequency dependent ways to the bridge just doesn't seem to hold up to either Chladni pattern or laser interferometry pattern analysis. That is NOT to say that different parts of the top do not respond in different ways at different frequencies, but the idea of coupling bass strings in one way and treble in another doesn't seem to work.

And I agree re. the Smallman sound...think banjo...and re. Spruce, though I like Adirondack for the slight stiffness to weight advantage...and since I have a fantastic source for it.

I'm also getting fantastic results with some 60 year old recycled redwood that was fencing up at Stanford U.

Next I get to try out some truly unusual wood from a giant sequoia that started growing 2,700 years ago and was 292 feet tall and 30 feet in diameter when it fell in the late 1960s up in the Sierras. It's the lightest wood next to balsa that I've ever handled.

oudin
08-05-2012, 02:08 PM
I have a daft question, but this would appear to be an appropriate place to ask it:

Has anyone ever experimented with alternatives to wood for bracing? Such as carbon-composites or ultra-light honeycomb materials? It seems to me that the holy grail of bracing is light weight combined with rigidity and strength. Surely there are much better alternatives to wood.

I enjoy the discussion that this stimulates even if it can be repetetive. I have messed with carbon fiber, balsa, Nomex and various stuff. I do not hold the idea of there being a holy grail of bracing in that one may prefer the "lesser" instrument. The lattice top guitars are a perfect example of this. They are louder, more sensitive, and have more sustain than traditional bracing systems. There is no doubt of this. But many people still prefer the traditional guitar. Another example could be the ukulele itself. Many of the tonal aims of the ukulele builder could be very easily acheived by building instruments with larger bodies, longer scale lengths, and more strings. But then it wouldn't sound like an ukulele. But I am all for (and in love with) the persuit of an ideal performance within the desired parameters. The appropriate place I see for unique bracing options is the opportunity to use woods that would otherwise perform poorly or not at all. Mya Moe often uses woods that would not perform well under normal circumstances. Without knowing exactly what techniques they use, they certainly get creative. I see a tremendous potential for carbon, nomex, etc. in these areas.

Pete Howlett
08-05-2012, 02:25 PM
There are two camps - traditionalists and innovators. I'm with the first tho I started out with the second. Experience has told me that if you want to get louder, change the tone and sustain you simply put a pickup in the thing and model the sound through a high performance amplifier and sound architecture module. It is very hard to make a 'bad' acoustic ukulele and only can you achieve this nadir by ignoring basic principles. If you build light with a sensibly braced instrument you will get the sound. Kasha, sadly has not been a great hit in the guitar making world and let's face it, these poisonous ideas that leak out of the guitar making world are distractions made to throw us reall men and women off balance:) As I have frequently said, a ukulele is 26 sticks of wood glued together in the right order with care and love.

ThomD
03-29-2013, 09:15 AM
Ukes I don't know. With guitars, to say Kasha hasn't taken the world by storm is certainly true. And to say it has not lived up to the theory is also true. So the style failed to be the only one, and it does not end up having a heavy underpinning of science associated with it (though I guess they tried). No better or worse than the rest.

Or in other words if there are 25 major brace styles where two have 80 percent of the market, and the other 23 have less than 1% each, it is right in the running with the rest.

People build it because it is pretty on the same basis that anything else out there is considered pretty by some. But it is more expensive to build so that is probably why it continues to have appeal among amateurs who could care less whether it takes an extra hour or two.

The Big Kahuna
03-29-2013, 09:30 AM
a ukulele is 26 sticks of wood glued together in the right order with care and love.

How did I ever miss this. Love it.

Pete Howlett
03-29-2013, 11:36 AM
I've said it many times - call yourself The Big Kahuna! Pay attention man :)

Chih-Wei Liu
03-29-2013, 04:51 PM
Years ago I've tried radial bracing on several of my classical guitars. There are two sets of fan braces which a lot like Kasha's. They are more prone to the deformation due to bridge rotating torque. Adding a bridge doc(like Eric Devine does) to solve the problem will inevitably add lots of mass to the vibrating center and change the sound. Little weight does count more than it does on a bigger heavier top like steel string guitar's.