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Thymej
06-03-2015, 04:23 AM
Is my common sense off or on (my common sense tells me no to the question below)?

In regards to Ukuleles, with solid tops and laminate sides and back, if all things being equal in build, does the laminate outside layer really make a difference in sound; being that the inside layer woods are unknown (at least to us consumers)?

If you took any brand and picked a solid top wood with the only difference between model 1 and model 2 was the outside laminate woods, and the tops being the same solid woods, would there be sound differences (excluding any sound differences from the fact that each uku is made from different pieces of wood but same type)?

Adrian Ortiga
06-03-2015, 04:32 AM
Yes it would make a difference , and i think they use "acoustic ply" or soemthing when building laminate wood instruments, this "acoustic ply" aint just some cheap ply wood but certainly cheaper than mahogany and other popular woods :)

spookelele
06-03-2015, 04:48 AM
IMO no. The outer layer of the laminate is so thin that I seriously doubt it affects the sound. The quality of the plywood underneath might, but the outer veneer on the ply is pretty much cosmetic.

k0k0peli
06-03-2015, 05:44 AM
The job of the sides and back of an axe is to bounce sound up to the top / soundboard to vibrate. If those inner surfaces are hard, there's more bouncing and sharper / brighter sounds. If they're softer, they absorb acoustic energy; the sound is softer. A uke with balsawood sides (absorbent) would sound rather different than one made of PVC plastic (reflective). That laminate's surface is going to be on the hard side for more reflection and resonance. If it's as hard as a solid wood used in a similar instrument, they should sound about the same IMHO.

ichadwick
06-03-2015, 05:47 AM
The purpose of the back and sides of an acoustic instrument is to reflect the sound back towards the front of the instrument. Sound predominantly comes to the listener from the top and the air hole. To better reflect rather than absorb the energy, the sides and back should be made of less elastic material than the top. Laminate wood (plywood) is generally more reflective than solid wood of the same thickness because it doesn't move as much when hit by the acoustic energy.

Dense woods like rosewood are better reflectors than spruce and cedar.

This is also why artificial material backs like the plastic in the Ovation are effective: high reflectivity, low absorption.

spookelele
06-03-2015, 06:09 AM
I used to think the purpose of the back and sides was just reflection.
But I've changed my stance recently

On some ukes, like my Rebel, the whole body vibrates.
I'm certain the back and sides are generating sound as well and it's kinda trippy.
Besides the crazy tone, the whole thing vibrating makes it feel creamy when you play.

On other ukes like my pono atsh, the body doesn't detectably vibrate at all.

Anyway.. I will say that the back/sides don't necessarily just reflect sound.
They can definitely participate in creating the sound.

robedney
06-03-2015, 06:38 AM
In my experience spookelele is right. When developing our carbon fiber violin I immersed myself in all of this stuff for a couple of years. The back and sides do indeed vibrate both with and independently of the air resonance inside the box. There's all sorts of wave propagation going on inside the box, and even the total mass of the neck has an impact on voicing (hollow neck vs. solid neck). Consider the fact that your clamp on tuner works so well on the peghead -- it's detecting non-air transmitted vibration generated first at the bridge. Further, if you affix piezo elements to various parts of the body you can measure and visualize the waveforms in different places. There's a lot more than reflection going on.

Now, as to the original question, I don't think that the top layer of laminate makes a truly audible difference. The fact that the material is a laminate as opposed to a solid does make a difference, and how significant that difference is depends on all sorts of things. As a general rule of thumb, however, it's very safe to say that the most important part of any ukulele is going to be the top plate (sound board). The back and sides are more subtle in the impact on voicing, but nonetheless important.

The density of the back and sides is not so much a matter of reflection as it is a sort of filtering mechanism. As the waves propagate through the material (as opposed to the air inside) they will at times multiply and at others cancel each other, depending on the material. There is a feedback loop going on as well -- the material vibrating and setting the air into motion at the same time that the internal air motion feeds back into the material and modifies the vibration. It all gets endlessly complicated. Even the best of the best can't successfully predict the sound of an instrument based on computer modelling.

In a violin the sound post mechanically couples the top and bottom plates. However, the uke responds very much like a violin without the sound post installed (something I've analyzed and measured). One last thought: The ceramic tile in your stall shower is an excellent reflector, creating an echo effect that makes even my singing sound better. Imagine a uke made with a solid wood top with back and sides made of ceramic tile. The reflection effect would be highly efficient, but it wouldn't sound like a uke.

Icelander53
06-03-2015, 07:13 AM
Is my common sense off or on (my common sense tells me no to the question below)?

In regards to Ukuleles, with solid tops and laminate sides and back, if all things being equal in build, does the laminate outside layer really make a difference in sound; being that the inside layer woods are unknown (at least to us consumers)?

If you took any brand and picked a solid top wood with the only difference between model 1 and model 2 was the outside laminate woods, and the tops being the same solid woods, would there be sound differences (excluding any sound differences from the fact that each uku is made from different pieces of wood but same type)?

Tough question. I'm sure there is a difference but would it be negligible? If the build is the same then I'm going to guess that laminate sides would not be an issue and might even help. I have a $200+ hog with laminate sides. For the money I couldn't ask for more, it's great. However it's never really competed well with my Ponos. It just doesn't have the fullness and depth they have no matter what strings I've tried.