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Why is there a taper on the guitar body?
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Author:  Burton LeGeyt [ Thu Nov 13, 2008 4:04 pm ]
Post subject:  Why is there a taper on the guitar body?
That is pretty much my question. Why is it there? I checked dream guitars because they list all of those measurements and the steel string tapers are all over the place, from 1/2" or less to over an inch. The classicals seemed to be uniformly much less. Does anyone have any info as to why this is or how different tapers effect your guitars besides the obvious overall lessening of the air volume? Thanks,
Author:  Michael Dale Payne [ Thu Nov 13, 2008 4:21 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
I assume it is a comfort thing combined with keeping the heel stock down under 4" while allowing the air chamber volum area to reach a desired volum area
Author:  Alexandru Marian [ Thu Nov 13, 2008 4:22 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
I think a very wide top bout is less comfortable if the player leans much on the guitar, which happens often with a SS. Classical's have only about 5 to 10 mm of taper, but they are smaller than D/OMs and the playing position is different, you are not really supposed to lean over it.
Author:  Hesh [ Thu Nov 13, 2008 4:40 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
I'm no engineer but is it possible that with the advent of the steel string guitar AND the greater string pull of same that less depth in the upper bout was more structurally rigid in resisting the neck and fret board extension's propensity to visit the maker's label?
Author:  Hesh [ Thu Nov 13, 2008 4:58 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
After I posted the above something that David Collins taught me came to mind. Much of traditional guitar construction was influenced by maximizing the materials at hand. Things that we often think are as they are by some brilliant designer or difference engine crunching numbers came to be in actuality because resources were scarce and every attempt possible was made to take costs out of guitar building and reduce operations and labor costs. Tapered sides require less zoot.

The D-35 is an excellent example of the above. BRW was getting hard to come by so Martin embarked on three piece backs.
Author:  Martin Turner [ Thu Nov 13, 2008 5:01 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
IMHO if youre back is arched then asthetically a taper towards the upper bout adds to the guitars "good looks". Just a thought.
Author:  MacD [ Thu Nov 13, 2008 5:03 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
It cuts down the opportunity for wolf notes to develop - if the back and front were parallel the body's air resonance would be strongest at frequencies with wavelengths that are multiples of the distance between the front and back.

Cheers,
Bri
Author:  Michael Dale Payne [ Thu Nov 13, 2008 5:03 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
Hesh wrote:
After I posted the above something that David Collins taught me came to mind. Much of traditional guitar construction was influenced by maximizing the materials at hand. Things that we often think are as they are by some brilliant designer or difference engine crunching numbers came to be in actuality because resources were scarce and every attempt possible was made to take costs out of guitar building and reduce operations and labor costs. Tapered sides require less zoot.

The D-35 is an excellent example of the above. BRW was getting hard to come by so Martin embarked on three piece backs.


nope that is not it as the cantalever force does not change by stiffening the rim. the Fretboard extension the same regardless of the height of the rim.

I still be it has to do with a combo of neck and heel material usage, comfort and desired air chamber volume. besides it looks cooler than if it was not there :D
Author:  KiwiCraig [ Thu Nov 13, 2008 5:34 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
I have 1 1/8 " on my Mahogany guitar which made it more difficult to cut the binding channels ,especially the Florentine cutaway. I ended up doing most with a Sloan purfling cutter.
It does however give it a very cool look and others comment on how comfortable it is to play.
Another observation is that it gives the instrument more air space inside the box before reaching the soundhole ( not quite a bowl back , but you get the idea ).
This is only speculation , but I have a gut feeling it's enhanced this guitar's performance.

Attachment:
olf 0084a1.JPG


.
Author:  Mike Mahar [ Fri Nov 14, 2008 7:32 am ]
Post subject:  Re: Why is there a taper on the guitar body?
I personally find tapered steel string guitar much more comfortable it they have pronounced taper. I don't know what, if any, effect there is on the sound. Perhaps Al has done the experiment.

ps. It looks like somebody REALLY got the wrong forum.
Author:  Burton LeGeyt [ Fri Nov 14, 2008 10:54 am ]
Post subject:  Re: Why is there a taper on the guitar body?
Thanks for all the replies guys. It's funny, I didn't even think of comfort to the player as a possibility, I assumed it was more to do with what Bri said about wolf notes but I wasn't sure. I agree that it does look better.

For those of you using radius dishes, is the taper straight from end to end? In the Cumpiano book it starts the taper just behind the waist but I imagine that sanding on the dish would make it all one (curved) plane. I don't use the dish but I always wondered about that.

Mike, what do you mean about the wrong forum?

Thanks guys.
Author:  Mark Groza [ Fri Nov 14, 2008 11:08 am ]
Post subject:  Re: Why is there a taper on the guitar body?
I agree on the comfort reasoning for the taper.However i also think the increased volume at the lower bout would increase projection and sustain.Think of it as a larger garden hose going to a smaller one.With the same amount of water going in, there would be more pressure going out and would take longer to clear the larger hose.So you would have more force coming out the sound for projection for a longer period of time for sustain.Just my 2 cents on this subject. :)
Author:  Wade Sylvester [ Fri Nov 14, 2008 11:40 am ]
Post subject:  Re: Why is there a taper on the guitar body?
I built one with an arched tapered back that has about a 10 foot radius from head to tail but the standard 15’ side to side. It’s about 3/4inch shallower at the head end. I think it contributes to the stiffness of the back and I do like the look. It seems to make the guitar look a bit less boxy. I can’t say if this has affected the tone so much though. It sounds pretty standard to me.
Attachment:
WholeAngl.jpg

I seem to remember something about a taper was a good thing for some tonal reasons too.
And that parallel plates could cause problems. Maybe it would be too much of a direct coupling of top and back? (Like Bri said)
Mark, I like your analogy too.
Great thread!

Wade
Author:  Mike Mahar [ Fri Nov 14, 2008 11:52 am ]
Post subject:  Re: Why is there a taper on the guitar body?
Burton LeGeyt wrote:
Mike, what do you mean about the wrong forum?

Thanks guys.

There was a post, which is now gone, that someone made concerning an on-line game called Runescape. It was clearly a mis-post of some sort. It looks like it was cleaned up.
Author:  Sylvan [ Fri Nov 14, 2008 12:10 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
If comfort was the issue it would make more sense to me to taper the guitar in the exact opposite from the way we traditional do it. I actually tried it and made a guitar where it's deepest point was at the neck end at its' shallowist point was at the tail end. I called it a "reverse wedge". Very comfortable to play. I did not notice any substantial difference in the tone or volume of the instrument and would make it that way again in a heartbeat if someone wanted it. The prototype sold immediately. See photos at:
http://www.wellsguitars.com/Gallery/Wedge/Wedge.html.
Author:  LanceK [ Fri Nov 14, 2008 12:40 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
Sylvan wrote:
If comfort was the issue it would make more sense to me to taper the guitar in the exact opposite from the way we traditional do it. I actually tried it and made a guitar where it's deepest point was at the neck end at its' shallowist point was at the tail end. I called it a "reverse wedge". Very comfortable to play. I did not notice any substantial difference in the tone or volume of the instrument and would make it that way again in a heartbeat if someone wanted it. The prototype sold immediately. See photos at:
http://www.wellsguitars.com/Gallery/Wedge/Wedge.html.


That is killer Sylvan! I took a peak expecting to see something that looked odd or different, but it really looks nice! At a glance you would not even notice it.
[:Y:]
Author:  JRE Productions [ Fri Nov 14, 2008 2:02 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
I would suspect much more the issues is with parellel top/back. When we build speaker cabs (which work in a simular fashion ..not exactly) we try to reduce the parallel lines. When we tune a recording studio room, we effectively try to reduce the # of parallel walls. This allows the sound waves to continue to bounce/reflect without hitting each other. Thus reducing things like phase cancellation and in some cases standing waves too.

I think even more comfortable would be if the guitar was thinnest on the bass side and thickest on the treble side. Instead of being tappered from end pin to heel, it could be tapered upper bout to lower bout. That would make throwing an arm over the guitar a lot easier.

J
Author:  LanceK [ Fri Nov 14, 2008 2:10 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
JRE Productions wrote:
I would suspect much more the issues is with parellel top/back. When we build speaker cabs (which work in a simular fashion ..not exactly) we try to reduce the parallel lines. When we tune a recording studio room, we effectively try to reduce the # of parallel walls. This allows the sound waves to continue to bounce/reflect without hitting each other. Thus reducing things like phase cancellation and in some cases standing waves too.

I think even more comfortable would be if the guitar was thinnest on the bass side and thickest on the treble side. Instead of being tappered from end pin to heel, it could be tapered upper bout to lower bout. That would make throwing an arm over the guitar a lot easier.

J


Your describing Linda Manzers Wedge.
Author:  Alan Carruth [ Fri Nov 14, 2008 3:01 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
Lance wrote:
"Your describing Linda Manzers Wedge."

Actually, it's the SMITH wedge, patent no. 3426638, granted Feb. 11, 1969.

There is a resonance between the top and back plates that shows up as a peak in the output. I've measured it somwewhere around 1100 Hz on a classical guitar, and, of course, it varies depending on the depth. The taper would lower the Q value or, if you prefer, spread it out over a braoder frequency range. One maker, who's opinion I respect, says that is a series of experiments on guitars with different tapers, he found that the more tapered ones had a more 'even' sound.

That said, I'd bet it's there mostly for comfort. I've been told by several women that a shallower upper bout is more comfortable for them to play. I will duck and cover now: the last time I mentioned this I was ridiculed as 'sexist', even though it was only passing on something that was said to me by people who ought to know.
Author:  JRE Productions [ Fri Nov 14, 2008 3:18 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
I once sold a 1964 Gretsch Country Gentlmen (17" body) to a very small and busty woman. It was the most ockward looking combination I had ever seen. Strangely...it also brought a smile to my face.


Cheers!

J
Author:  Mike Mahar [ Fri Nov 14, 2008 4:19 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
Alan Carruth wrote:
Lance wrote:
"Your describing Linda Manzers Wedge."

Actually, it's the SMITH wedge, patent no. 3426638, granted Feb. 11, 1969.



In fact, the patent was filed in 1966.

However, I recall attending a lecture in college with a title something like "Columbus really did discover America". The first part of the talk was a description of the Sagas and artifacts that document Leif Ericson's trip to and settlement of New Foundland around 500 years before Columbus. The speaker's contention is that Ericson's discovery is irrelevant because he didn't bring the information back to Europe which remained ignorant of the Western Hemisphere for centuries. Columbus's discovery on the other had galvanized the whole of Europe and it was reported to be the topic of discussion at the Czar's palace within weeks of Columbus's return.

The is something to be said for giving credit to those who innovate AND popularize an idea. Manzer's and Cumpiano's disputes aside, The idea seemed to catch on and spread once Linda started doing it.

By the way, the wedge guitars that I have played have all felt like parlor guitars and sounded like full bodied guitars.
Author:  KiwiCraig [ Fri Nov 14, 2008 4:30 pm ]
Post subject:  Re: Why is there a taper on the guitar body?
The wedge shaped geometry ,as in Linda Manza's/ Cupiano's , also has the affect of tilting the angle of the fretboard , so that your fretting hand's wrist has to find a more accute angle . Not much , but noticeable .
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