Different bracing - not much sound difference

On the last set of 3 tenors, I figured I would try out several different bracing styles, to see which one sounded the best. I have been moving to using 2 fan braces, but making the braces taller and thinner to maintain the strength/stiffness and minimize the weight. I fixed a friends Kala (put on a new top) and it had an X braced top, which I copied and it sounded pretty good. I have also been playing with curved, 'fulcate' laminated braces, which are very stiff, strong, and light.

Two of the bodies are veneered black locust (our best local tone wood, stiff and reasonably heavy), and the third is casuarina, a new wood I have been experimenting with, which is very hard and heavy, stats comparable to the ebonys. All have redwood tops (recycled from old roof-top water tanks).

I figured that the different bracing styles would yield significant differences in volume and/or tone. The results are surprising.

The sound of all three is very very similar, so much so that you really can not quantify any difference at all! Played one way, this one sounds somehow 'brighter', but play another way, that one seems 'brighter', etc.

The sound of all three is very good, nice and rich (I have them all set up as low-G with Southcoast strings), great volume and sustain, nice balance between base and treble, good sound up the neck. The bracing style seems to make little difference in the end. Maybe all the discussion/agonizing over bracing styles should be decreased in importance.

(In the pictures of the instruments there is a dogwood concert on the left which is not part of the experiment)

Thats a very interesting post Jon. Thanks for sharing your results. Convinces me to just stick with the three brace fan system that I have found good results with. Those are lovely ukes you are building. Keep up the good work
Brian

I'm impressed by the workmanship you have put into theses ukulele's. Interesting experiment too. Maybe being über precise and dawdling over "some" placements of parts is not necessarily going to gain much for the effort.

Yeah, I'll bet they sound like, well, ukuleles... You might have a point. Maybe bracing schemes are over rated... The back of that one second from the left looks a lot like ziricote. But I think you said it was black locust? Picture of some ziricote I used. Similar looking.

Bracing schemes certainly can be over rated. Sometimes you can make big changes and nothing seems to happen, then you make very small changes and a lot seems to happen. So in that respect it can be very difficult to predict. I've even made an instrument that didn't have any bracing at all. Guess what? It sounded perfectly nice. I'm fairly certain that it had a better (ie, deeper) bass response than the same model with bracing. Don't take it to an extreme though i.e. you can do anything and everything will work. It doesn't seem to work like that, at least not in my experience. Providing you are making enough changes you will have failures, instruments that just don't seem to work or are lacking in a certain aspect. You can't take bracing as a factor that stands alone though, it's just one of many. Those lattice braced guitars don't function just because of the bracing. It's the bracing coupled with an extremely thin top which is also coupled with sides/backs that are less acoustically active. No one can tell me that they don't sound different. It's the combination of all those factors that defines or alters the type of sound.

Kekani said:

Top thicknesses?

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Resulting in top "stiffness," which may mean that the braces had the nearly same elasticity and presented no difference in damping the top. Either that, or the bass and treble tonal outputs (to the ear) may have been pleasant enough that the overall sound seemed to be equal and nothing was sonically confined. Maybe not, and there is no difference in frequency response of the three boxes -- at least to the ear.

If any of the bracing patterns created a stiffer top, then I've been told that the resulting sound should be more treble and less lower frequency output.

It does seem that within a given stiffness 'envelope', the exact bracing style makes little difference. All three of the bracing patterns were of (I think) similar stiffness. That is my impression from flexing the top before it is glued on. I have been going increasingly light with bracing, while still keeping enough strength/stiffness that I will not get much bridge rotation. (On stringing up these three I did not notice any bridge rotation.) The redwood is a fairly soft and weak top, compared to spruce, even with the very fine grain of this redwood (30-50 grain lines/inch) so the bracing has to be a bit more robust since one is not going to get much stiffness from the top itself. Since with these I see no bridge rotation I can perhaps go a bit lighter on the braces ... I do think that the softer/weaker redwood contributes to a deeper base response, which I like.

The tops are .08" thick.

sequoia - The ziricote one is ziricote veneer laminated to black locust. The black locust is local to me (I cut it with a chain saw to start with) and is a very nice tone wood. It has the disadvantage of being 'boring'. Kind of a drab yellow olive color that never gets curly, or swirly grain patterns, or strong medulary rays or anything. So I figured out how to veneer it, and can now make it look like anything, and really fancy veneer is pretty cheap for the amount needed for a uke. I can even use a burl veneer (the other one here), so the uke looks like it is made from a burl, which one could never do with solid burl wood because it has no strength.

Thanks so much for posting this. I'm not a builder, I don't even know if I could glue on a bridge. But I have wondered about this for some time. I saw a video a few months ago of a guitar that was practically nothing but braces. The paper thin wood was shredding off of it, but it still sounded great. Go figure.

YEP. It's what to expect from a ukulele. I am looking at a completely different top configuration and will use a lattice brace system so I can create an evenly responsive plate. I don't expect there to be a huge sound difference but I do expect to be able to offer some snake oil with this design...

Pete Howlett said:

I am looking at a completely different top configuration and will use a lattice brace system so I can create an evenly responsive plate. I don't expect there to be a huge sound difference but I do expect to be able to offer some snake oil with this design...

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That is the thing: Do we even want an evenly responsive plate? Boring? Practically everything in an ukulele is asymetrical and rounded. Why use a square linear bracing system? Why, because it is the strongest best geometry. However music is not symmetrical and it is the round angles that produce that beautiful sound we call music. If a bracing system makes no difference, I say that is the way to go. Stable. But I'm not convinced. We haven't got the report in from Michael yet. Personally I don't have the guts to build a lattice braced uke. You go first... Nobody ever said you sold snake oil Pete.

I think Pete was employing some of that dry British humour...

If you want to minimise weight, make your bridge smaller.