Thread: solidbody shapes

Originally Posted by HiString

Unless you are able to do (microscopic) analysis of the timber structure for a complete body blank you are never going to have a 100% guarantee.......the variables of nature will see to that, and that's one of the beauties of working with timber. God, how boring would it be if every guitar sounded just like the next............and the next............and the next.........

You can have a fair bit of control over the sound of an acoustic without having to resort to microscopic analysis of the tonewood you're using. Tap tones are one example of this. It takes a bit of practice but by tapping a top you can get a fair idea as to whether or not its going to sound good or not in the finished guitar. One can note the change in tap tone as the to gets worked down to final thickness. One can go a step further and couple the top to a loud speaker and examine response of the top to differing tones generated by the speaker.

That said I agree that life would be boring if every guitar sounded the same and there werent a few factors out of the control of the luthier.

Micoscopic and scientific analysis wont tell much. like kiwigeo says its the tap the tells you. Inn electrics it dont matter so much as much of the tone is generated from pickups, bridge and neck. The body is not hugely importatnt i don reckon. But certain types will give different colour say like a softer more fibrey wood like a mhaogany will give a rich tone where a maple body or hard and dense wood will give a bright tone. Really its just a kind of colouration a bit like adding different kinds of sauce to a pie.It tastes like a pie but pickles is different flavor to chili. Use good wood and top quality hardware it will sound great and the choice of woods will coulor the tone not make it worse or better.

I reckon there's too much voodoo in using special woods and I reckon mainly started by the guys selling the woods to keep you buying it. Its more about how you build it than what you build it out of. Like benedetto says when he makes a guitar for his book out of crap wood. It sounds like the ones made of so called master grade tonewoods he reckons

Ooops, I meant to throw something like or , etc., in after "microscopic analysis".

There was an interesting programe on ABC a short while ago about violins, all about how they are mabe and who made and makes them, details about all the facts and myths surrounding the great makers like stratavari.

there was quite a lot of good science covered and some interesting comments form current eminent violin makers.

one interesting segment was a double blind test of 4 absolute top shelf violins only one of which was a genuine "good" stratavarious.

neither the player or the panel knew which was which.
One of the members of the 5 man panel was a top eminent maker, one of the violins was his. I seem to think he may not have been aware.

The panel was instructed to comment on all the violins and specifiocaly to identify the strat"

(you are going to like this)... all of them selected the one made by the panel member as the strat' even the bloke who made it.
All done by as proper science in a high powered research uni.

BUT I digress

It covered a number of questions concerning what made a strat' sound soooo gooood. was it the wood, was it the varnish......... and so on.
all sorts of good science and investigation.
The fact seems, all the "special factors" that are suposed to be why the old violins sounded soo good ended up being of little or no significance.

any way

one of the issues was shape.
a couple of the makers had been experimenting with shape for years ( some of these guys weren't young).
The had built conventional shapes and all sorts of odd stuff even square ones.

The conclusion is overall shape doesn't matter a bugger.
Its the geometry, mechanics and the structural properties, the amount of wood and the thickness.
Overall shape was only significant in that it may influence where particular eliments of the instruments structure are placed.
Concluding that most of the traditional shape was art a fashon and nothing else.

very interesting.
cheers

As often happens, this thread has veered away from the topic, however, there are some interesting bits and pieces of info regarding timber and hollow bodies that may not have emerged otherwise.

Following on from Soundman's post, people may find the following link interesting. Out of courtesy to the main person concerned, I won't cut and paste his pics and/or info but he is a Australian who has definitely re-thought violin designs........http://www.mimf.com/cgi-bin/[email protected]

What soundman says is right that the body shape is art/fashion. Pickers are prett conservative and like trad style guitars. Bass players a re more willing to use instruments that look oddball.

I will say this that every one I make don't sound the same as the last one of the same type. It is always a surprise [usually good] when you first plug her up through the different amps to see how she sounds I notice each one has a slightly different voice and sounds better through this amp or that amp.

if they was all exaclty alike you wouldnt bother making more would you?

Originally Posted by soundman

The conclusion is overall shape doesn't matter a bugger.
Its the geometry, mechanics and the structural properties, the amount of wood and the thickness.
Overall shape was only significant in that it may influence where particular eliments of the instruments structure are placed.
Concluding that most of the traditional shape was art a fashon and nothing else.

very interesting.
cheers

My thoughts on violin shape:

Even if the shape of the violin has little influence on sound (acoustic guitars are a different kettle of fish IMO) the shape of a violin (and the guitar) evolved for a reason and it wasn't just fashion. The narrow waist section of the violin is there to allow unrestricted passage of the bow across the outer strings. Likewise the waist of a guitar allows the thing to sit on one's knee without continually falling off same.

I disagree that an acoustic gituar is a diferent kettle of fish to a violin.

They are precisely the same kettle of fish.... the structure while slightky different and the application a little different the mechanical and acoustic principles and systems involved are the same.

so as far as the acoustic and tonal performance goes.... shape don't matter a bugger, so when it comes to a solid body instrumentshape will matter even less.
Which was the original point in question.

so when looking for where the difference and therfore the art and magic is and comes from there are a whole lot of other variables that do matter..... shape does not.

cheers

There is also the theory that the shape of the violin and the guitar were based on the shape of a woman.......

Obviously back in the early days of the guitar women were a different shape than they are today.

well thats a pretty safe statement...... afterall most shapes in art can be atributed to only a hand full of things... the woman would probaly be the most popular.


cheers

Check out Alan Carruth's article on free plate tuning in the GAL Big Red Book - Volume Three (pp 136 - 172).

He experiments with Chladni patterns for square plates and then looks at how changing the shape of the plate changes the pattern.

Amongst other things Carruth establishes that 'Free plate nodes are generally combinations of lengthwise and and crosswise beam modes, and torsion modes. Because these modes involve the displacement of areas of the plates, the nodes between the displaced areas form lines. The shapes of these node lines and the node frequencies are influenced by the SHAPE and thickness distribution of the plates, their size and material, the presence of bracing and the Poisson's ratio of the material."

Carruth also notes that although the principles of violin acoustics can be applied to guitars there are differences. He further notes that the acoustics of the archtop guitar are the closest to those of the violin.

Cheers Martin

An interesting history of the guitar can be found here http://www.classicalguitarmidi.com/h...edieval_Europe and photos including a Stradivarius guitar here http://www.classicalguitarmidi.com/h...evolution.html

Originally Posted by soundman

well thats a pretty safe statement...... afterall most shapes in art can be atributed to only a hand full of things... the woman would probaly be the most popular.


cheers

The most popular....and guaranteed to cause the most argument

Originally Posted by HiString

An interesting history of the guitar can be found here http://www.classicalguitarmidi.com/h...edieval_Europe and photos including a Stradivarius guitar here http://www.classicalguitarmidi.com/h...evolution.html

Thanks for that HiString. Not many people are aware that Stradivarius made a few guitars as well as violins.