Interesting hypothesis for the learned to consider

sebastiaan56 · Post by **sebastiaan56** » Sat May 23, 2009 6:02 am

see http://salilab.org/samo/web6/influence.htm

comments?

Allen · Post by **Allen** » Sat May 23, 2009 6:54 am

It's making my head hurt thinking that there is yet one more thing to take into consideration. I'm out to the workshop to make some dust.

jeffhigh · Post by **jeffhigh** » Sat May 23, 2009 7:14 am

very interesting,
Does he ban sandpaper from ever touching a soundboard?
would think that final preparation and finish application would modify these results.
A little suspicious of some of the graphs without numbers.

Selling (for an extra 100 euros) a digital moisture recorder as a prerequisite to warranty for cracks and deformation is an interesting proposition

Thanks Sebastion.

obmit · Post by **obmit** » Sat May 23, 2009 11:13 am

I think this is a bit hairy fairy.

The only thing that changes when sanding, planing and thicknessing and adjusting feed speed is surface finish.

-Sanding, flat with thousands of scratch marks (Varies on Grit)

-Planing (machine), Larger ripples slightly irregular.

-Thicknessing, smaller ripples spaces evenly this changes as you alter feed speed.

So IMHO the only thing changing vibrations would be these ripples caused by machining which in all cases get sanded down to a micro finish with sand paper anyway at final finish.

The only way you could test this would be to make say 3 - 4 identical Guitars using different machining techniques.

The only thing IMO that would make and acoustic change would be if the timber was Air dried or kiln dried.

That's my 2cents

Cheers

Tim

Dominic · Post by **Dominic** » Sat May 23, 2009 2:15 pm

I agree with Tim. The proportion of the final surface we are talking about here is tiny. Maybe 99.99% of the wood on a planed and a sanded top are within the thickness of the top and are the same. Also, seems a lick of sealer would bind any loose wood fibres and further reduce any percieved difference.
Unless they are saying the thinning process somehow effects the properties of the whole top, not just its surface. But they have not really explained it very well.
Dom

Runn3r · Post by **Runn3r** » Sat May 23, 2009 3:32 pm

No implications for guitarmaking could as yet be made. Perhaps the observed correlation is not even important for making resonant boards of real guitars. Only future experiments can help us understand the interplay between the cutting process and the acoustic properties of the resultant resonant board. However, the current results and experimental set-up provide a good starting point to address this larger question.

tht's what struck me at the end....

kiwigeo · Post by **kiwigeo** » Sat May 23, 2009 3:40 pm

Mmmmm...looks like one of my bracing jobs after couple of vodka lime and sodas.

graham mcdonald · Post by **graham mcdonald** » Sat May 23, 2009 4:41 pm

He uses lots of big scientific words and formulae which may or may not make any sense at all. It needs someone like Al Caruth or Graham Caldersmith to interpret for the rest of us. The wiggly braces are just weird, and the 'rule of consonance-dissonance' is equally as puzzling.

We should remember that Michael Kasha's scientific reworking of the guitar soundboard hasn't changed the wold in the 30 or so years since it was touted as the next Great Leap Forward in guitar design. Greg Smallman has shown us that the important thing is the stiffness and the resonant modes of the soundboard. This bloke's wiggly braces might well do that as well, though he seems more focused on some objective measure of 'tone'

All grist to the mill

graham

Dominic · Post by **Dominic** » Sun May 24, 2009 12:21 am

What are you talking about Martin? I've had a couple of vodka lime and sodas and those 8 braces look pretty straight to me.

Dom

Joe Sustaire · Post by **Joe Sustaire** » Sun May 24, 2009 2:12 am

I love that vodka lime and soda bracing job!!!
Reminds me to loosen up a bit!

Joe

Lillian · Post by **Lillian** » Sun May 24, 2009 3:41 am

Maybe I missed it, but I find it odd that he doesn't qualify how the boards were dried. If you are intent on reaching a repeatable conclusion, shouldn't you try to keep certain variables as consistent as possible? Surely how the wood was dried, at what thickness it was dried, how long ago it was dried and any hot/cool or humid/damp cycles would affect it as well. Did the test samples come from the same tree, have the same ring count and size? And is he lumping scraping into hand planing?

Nick · Post by **Nick** » Sun May 24, 2009 8:56 am

I doubt if the very nature of wood will allow his results to be repeatable. How does he know that these results are the result of how he cleaned up the surface or as a result of the internal structure of the wood? Maybe repeatable if we had a consistent man-made material but wood is too variable (even between 'sister' boards,pitch pockets e.t.c) for me to take too much notice of these results & put them into the "must do" basket.
Then of course these results are done on wood in the white, what happens when it's finished? Again, to me at least, it's just another builder using scientific 'results' to justify the way that they do something & who knows about that bracing?

as Graham said, Kasher proved there's more than one way to skin a possum but is it necessarily any better? Best of luck to him if it is & "vive la difference"

Clancy · Post by **Clancy** » Sun May 24, 2009 3:29 pm

Having spent 7.5 years of my life hanging around the hallowed halls of a university (part time study

) obtaining an engineering degree , I am confident in saying that 90% (unqualified result) of investigative science & engineering is just a means of demonstrating how smart we can be at proving nothing. The other 10% (again, a figure I scientifically plucked from the air, and which can be repeated and proved thus) are where major breakthroughs occur, usually by accident while trying to do something else.

Having said that, if nothing's looked at, nothings learned, even if it is by accident (newton didn't mean to discover gravity, he just looked at the rotten thing that clobbered him from above)

Clancy · Post by **Clancy** » Sun May 24, 2009 3:38 pm

What do you mean those braces aren't straight.
I've got a theory that says they are!
It's the rest of you that are wobbly, especially after all those vodkas (and you've got to watch them limes)

Runn3r · Post by **Runn3r** » Mon May 25, 2009 10:47 am

Craig Clancy wrote:What do you mean those braces aren't straight.
I've got a theory that says they are!
It's the rest of you that are wobbly, especially after all those vodkas (and you've got to watch them limes)

...it is not the spoon that bends...Neo

...it is yourself

kiwigeo · Post by **kiwigeo** » Mon May 25, 2009 10:51 am

Im not a scientist...Im a Geologist....mortal sworn enemy of Engineers.

Nick · Post by **Nick** » Mon May 25, 2009 11:47 am

kiwigeo wrote:Im not a scientist...Im a Geologist....mortal sworn enemy of Engineers.

The earth may render it's secrets to you, but you shall not defeat us GeoMan.......Engineers will survive. Rock hammers are no weapon against the mighty shifting spanner.

Clancy · Post by **Clancy** » Mon May 25, 2009 11:49 am

I studied to be a rock doctor for a year and a half.
Bombed out on the field trip assignments (too much socialising in other tents rather than wandering around with a geo-pick).
Left uni and didn't go back till I was divorced and aimless ten years later.
All I could get into was electrical engineering (they really must have been desperate to fill the mid year entry classes)

sebastiaan56 · Post by **sebastiaan56** » Mon May 25, 2009 12:44 pm

Craig Clancy wrote:I studied to be a rock doctor for a year and a half.

youtu.be/

What what do you study to be a Rock n Roll Doctor...

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Interesting hypothesis for the learned to consider

Interesting hypothesis for the learned to consider

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