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chuck in ny
02-17-2017, 10:06 AM
has anyone had success with heavier soundboards, and whatever your observations are if you did.

Timbuck
02-17-2017, 10:33 AM
has anyone had success with heavier soundboards, and whatever your observations are if you did.
First one I ever made...it had a 2.5mm thick utile mahogany soundboard, it was very treble no bass end and no volume ....It looked great ..I still have it and play it when I don't want to disturb anybody.

chuck in ny
02-17-2017, 12:04 PM
well, without the lower register you don't have much of an instrument. interesting to hear your experience. maybe thick would work with a softwood top.

kohanmike
02-17-2017, 01:35 PM
I had a gypsy jazz Grande Bouche tenor cutaway uke made with a flame maple top that was rather thick. It has what my other uke player friends describe as a small voice, not much projection or sustain, which is true, but it does have a very nice tone.

Moore Bettah Ukuleles
02-17-2017, 05:46 PM
First one I ever made...it had a 2.5mm thick utile mahogany soundboard, it was very treble no bass end and no volume ....It looked great ..I still have it and play it when I don't want to disturb anybody.

Nice for cutting fish on though. ;)

sequoia
02-17-2017, 06:23 PM
Yeah, 2.5mm is pretty thick (that is 3/32" or about 94 mil for those of us that do Imperial). I think what happens is that a top that thick tends to absorb the string energy and instead of vibrating it basically just sucks it up and goes "thunk". Thunk is not a good sound. On the other hand I have made tops too thin I think and they don't go thunk, they just so of go "ping" because they can't absorb the string energy. It is the Goldilocks effect: Not too thin and not too thick. I think it was Beau that said: Just 80 (mil) for everything (back, sides and top) and you wont be too far off. Wise words. However, I've been using a lot of torrefied spruce lately and I find that even 80 is a bit thin because it is so dry and it likes 85 a lot better. So each wood is different, but you can't go far wrong with 80 cause Beau knows. Another general rule of thumb I think is that hardwoods can go thinner than 80 and are more forgiving than spruce when you get into the 70's or even high 60's. Anyway, all of this is very general and over simplified. And then you add the issue of bracing....

Timbuck
02-17-2017, 10:21 PM
My cuban mahogany soprano tops are 1/16" or .0625" = 1.6 mm.

Allen
02-18-2017, 10:20 AM
You need to specify the size of the instrument for this to be pertinent. And if and what type of bracing you expect to use.

2.5 mm in a Western Red Cedar on a Baritone would be pretty close to being spot on with light bracing.

sequoia
02-18-2017, 05:09 PM
You need to specify the size of the instrument for this to be pertinent. And if and what type of bracing you expect to use.

Sorry. I was referring to a tenor sized instrument with fan bracing. To me we are back to the big "black box" of ukulele construction and I certainly have not figured out how to do it consistently. Here is where experience and feel come to the fore and frankly I'm not there yet. But I'm starting to get a glimmer.

jcalkin
02-19-2017, 03:44 AM
Thick and heavy are two different things. At Huss & Dalton we'd flex test every guitar top and thin it out until we got the deflection we desired, which was a fixed number. Mahogany and softwoods used the same scale, and mahogany didn't always end up on the thin side as you might expect. Spruce that was "fluffy" or slightly off the quarter had to be left somewhat thicker so as not to exceed the scale of flexibility, but suffered nothing in sound quality and often sounded better than stiffer/thinner tops of the same specie. After testing a few hundred tops I could tell by hand flexing how a top was going to test on the machine, and this ability seems to have stayed with me. While the deflection figure never changed, over the years I began to carve the braces lighter and lighter. Dealers began to report that our guitars were really coming to life and left little to be desired, sound-wise, compared to other up-scale guitars.

All this should transfer to the uke, using a new set of deflection figures. Once deflection is under control the bracing system you use can be pretty much standardized. The real take away here is that playing it safe probably inhibits the potential of your ukes, and that until you have a top fail you'll never know how thin/light is too much.

sequoia
02-19-2017, 07:59 PM
The real take away here is that playing it safe probably inhibits the potential of your ukes, and that until you have a top fail you'll never know how thin/light is too much.

Yes, failure is how you learn. If you don't know what is wrong how are you going to know what is right? This knowledge is accrued through the process of doing again and again and again, etc. As in over and over... I have seen videos of luthiers using a quantitative deflection device. Like taking a 4.7 pound weight (dreadnought guitar) and seeing how much deformation takes place along the top plate and measuring the deflection. I really think this allows the production factory to output a consistent thickness that varies with the different types of wood encountered but gives a consistent sound (hopefully good). Dial in deformation and deflection to a set number and bingo! The top is going to sound pretty much like the last set and the one before it.

This is all well and good and I get it. It takes out the experience part. Anybody can sand and read numbers on a digital output. 14.0019/0.44444 = 1.6.0017 = Good sound. But it also takes out the experience and art of flexing a top until it "feels right". This is why buying an uke from a good luthier is so expensive. He doesn't need the frigging numbers. It just feels right. ... Here is the question: Can a low production luthier that doesn't use quantitative deflection ever really be as consistent as a big time manufacturer that uses quantitative measurements and does consistency even matter as long as the damn things sound good? In other words: Does quantitative trump qualitative when it comes to building great sounding ukes?

lauburu
02-20-2017, 08:31 AM
Does quantitative trump qualitative when it comes to building great sounding ukes?
Could we keep Donald out of this forum? It's bad enough that he dominates the news.
Miguel

jcalkin
02-20-2017, 09:30 AM
Yes, failure is how you learn. If you don't know what is wrong how are you going to know what is right? This knowledge is accrued through the process of doing again and again and again, etc. As in over and over... I have seen videos of luthiers using a quantitative deflection device. Like taking a 4.7 pound weight (dreadnought guitar) and seeing how much deformation takes place along the top plate and measuring the deflection. I really think this allows the production factory to output a consistent thickness that varies with the different types of wood encountered but gives a consistent sound (hopefully good). Dial in deformation and deflection to a set number and bingo! The top is going to sound pretty much like the last set and the one before it.

This is all well and good and I get it. It takes out the experience part. Anybody can sand and read numbers on a digital output. 14.0019/0.44444 = 1.6.0017 = Good sound. But it also takes out the experience and art of flexing a top until it "feels right". This is why buying an uke from a good luthier is so expensive. He doesn't need the frigging numbers. It just feels right. ... Here is the question: Can a low production luthier that doesn't use quantitative deflection ever really be as consistent as a big time manufacturer that uses quantitative measurements and does consistency even matter as long as the damn things sound good? In other words: Does quantitative trump qualitative when it comes to building great sounding ukes?

You've entirely missed the point. First you discover the the greatest safe deflection number, then you play with such a top until you know how it feels, then you make each successive top feel like that. That's the experience, and it isn't that hard. But if a top never fails you'll never know what the safe threshold is. Or you can just use the .070" rule, be safe, and maybe make wonderful ukes. Playing on the edge isn't for everyone. But you still haven't escaped a number, have you?

printer2
02-21-2017, 01:24 PM
Here is the question: Can a low production luthier that doesn't use quantitative deflection ever really be as consistent as a big time manufacturer that uses quantitative measurements and does consistency even matter as long as the damn things sound good? In other words: Does quantitative trump qualitative when it comes to building great sounding ukes?

A big league luthier was describing that he thicknesses a top down to the point where its stiffness when wobbled sounds like cardboard. So rather than using weights he uses the air and his hands to get the tops to have the same relative stiffness before he braces them. He seams to have a good batting average with the sound of his instruments. Mind you he has many years experience to rely on.