Official Luthiers Forum!

Hi Steve. Yes there would be an individual tube( You can Kind of see it in the picture) for each string to guide them.

Bill, your ambition is great and shouldn't be squelched. What I think most here are saying is that eagerness can cause you to loose sight of the forest through the trees. Example: I knew a guy that built his first guitar in a class. He had NO woodworking skills but had read somewhere that a thin top is "BETTER' than a thicker top. So right out of the box he decided that he would thin the top more than desired. Nothing could convince him otherwise. So to the thickness sander he went and brought the darn thing to .045". It was like a floppy piece of paper. When it was finished, the guitar sounded like YUCK because the top was so floppy. Then about 10 minutes under string tension the thing folded up on him. The point I'm trying to make is that had he had the experience of a few guitars under his belt he might have come to the conclusion that thinner is better TO A PIONT. And that might have been a successful guitar.
I think all of us here have had grand thoughts as to how to improve the guitar. I know after my first I must have had a thousand ideas swimming around in my head. But I got some advice from an extrememly wise man, Charles Fox, that said "just build guitars for now. When you've got 50 or so under your belt, you can start playing around." At first I thought he was being a crank old such-n-such for taking the wind out of my sails but now I've come to realize that he really knew what he was talking about. Probably 80% of my "improvements" have been tossed as I'm constantly learning new and different things and realizing that certain things won't work.
My advice, give it time. Keep it in your head and improve on it on paper. When you have a few under your belt then maybe dive in and see what will happen.
As to the design itself: It was said before and I'll repeat the feeling that there won't be enough string energy to drive both tops. Especially on a classical, where builders often struggle trying to get the strings to drive one top, I think you'll get the oposite of what you are looking for. A quiet, dead guitar.
Best of luck in your ambitions.

Bill, I think you like most of us are always thinking about guitar designs. A couple of things I see right off the bat is the string "afterlength". In violins the length from the break point om the bridge to where they are actually terminated is call the "afterlength" and it has an effect on the tone of the instrument. Violin makers adjust the tailpiece to get that measurement where they want it. Steve's point about threading the strings is also a major problem if you don't come up with a solution. Also the air chamber created between the two tops will in effect change(I think)the main air resonance of the instrument. This is different from the two top system using a nomex core lamination. Also would the design not reduce the torquing effect of the bridge on the top? This is where a lot of the "character" guitar sound come from.

Did you have a specific idea you were shooting for with this design? Why do you feel it is a better design? This is not criticism just an honest question.

Experience with building guitars, violins and a very techincal career has taught me the best way to fix something is A.) understand how it works to start with. Are you trying to fix something that ain't broke? B.) define the problem you are trying to correct. C.) devise a fix for that problem with out breaking something else in the process.

Don't take offense ay all the posts. Your design idea may be new but the struggle to improve our instruments is something all of us are familiar with.

Your original question made me think through the concepts and between that and the informed responses, I have learned something, so thanks for helping me learn.

The thought that came to me right away was that after the strings break over the saddle on the top, there isn't very much energy or tone in the lower string length to make any difference, or probably any extra sound on that inner plate. If I wanted to drive that inner plate I'd put a soundpost under the saddle and in-between the two plates, connecting them. In fact, taking that idea further, I'd make the bracing for both plates integrated, as one. That would let you keep it light enough, keep it from collapsing together from string pull, allow you to build in holes to slide the strings through while re-stringing.

_________________
Mark Swanson
Swanson Guitars
http://www.MarkSwansonMusic.com

Hi Pwoolson. Thanks for the wisdom.

I stated earlier that I'm not going to try a radical idea like this for my first guitar. I've gain a different perspective from this thread. I understand where you guys are coming from and I think I will tone it down for my first build.

As you suggest, I am working everything out on paper. I have three possible designs that "might work." ie.. this design and another I've posted plus one that is not very different at all.It has just a slight modification of the bridge. Also I have come up with another. I'm not a hundred percent sure they would work. As i do them though I am learning alot. As i've stated earlier: I should learn more and then I can decide for myself if they would work. I've also learned , from this thread,why this design wouldn't work. It has given me some great knowledge that would probably have taken me along time to figure out. Perhaps posting such things is not so bad.

Hi Barry.

About the threading I mentioned what I would do for that in my reply to Steve. There would be six individual tubes running from the bottom bridge to the top.

I thought it would make it louder, because the sound comes from the vibration of the strings and soundboard. I thought why not have two soundbourds with the strings attached to them. So they could vibrate both soundboards, thus making it louder. I was unaware of the aspects about why this wouldn't work. I can't build a guitar right now so this is what I'm doing.

I'm not taking offence. This post has taught me a lot. It was just the few initial posts that didn't help very much and i didn't see their point. They didn't state a reason of some sort why my post was invalid and not understanding my situation made an assuption. Oh well. No big deal.

Hi Mark.

Do you mean the two soundboards would be attached with a sort of post bracing?

Bill, If I'm understanding Mark right that's exactly what he's saying. Think about it this way. If you hold a string at one end and at about 3/4 to the other end. Pluck it and it will vibrate as a string should, but the remaining 1/4 hanging off the end won't do much at all. You fingers are acting as a saddle which is going to stop all the energy. So very, very little vibration is going to move the second bridge. The way I see it you have two options with this design. 1) Let the second top float and just be moved by the vibrations of the first top. This would take a lot of figuring to know exactly where to put the two tops in relationship to each other. 2)have the two tops connected by a sound post at the bridge area. Then you would only drive the first top conventionally and the second would be driven by the first. Lots of energy will be lost here as well.

I'm really beginning to see that this design has some major flaws.

Yes, that is what I meant. But I'd go further than that- think of a "double top" guitar done with a nomex layer in the center, then imagine a double-top guitar with a LOT more space between the two layers and instead of nomex there would be the bracing. The bracing would need to be worked out and be attached to each top.
But these are just thoughts off the top of my head....it would be a lot of work and it wouldn't be something I would try...only in my head, I think. <G>

_________________
Mark Swanson
Swanson Guitars
http://www.MarkSwansonMusic.com