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What effect do you think this design would have?

billb38563.0817476852

What exactly are you trying to achieve? Also, materials for each section? Depth?

Interesting....a top on the inside, where the strings anchor to another bridge eh? Not sure about that. I would have to think long and hard on it.
On one hand, most of the string energy will be transmitted to the top through the saddle. I'm not sure then what coupling the strings to an inner braced plate would do other than create sympathetic tones at extremely very low levels. You might be cutting off your nose to spite your face here, since you will lose valuable body depth to do this. All you can do is experiment and see what happens. It might be awful, but then again it might be great. Perhaps if that inner plate were deeper in the box, close to the back. Of course it removes the tonal coloring a guitar gets from the back, unless it is the same wood as the back.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

I agree with Highdrawlicks...100%
This Forum is about sharing great ideas and skills relating to guitars in a more conventional theme.
Walter

I build full time yet I stray very little from established designs. As far as I am concearned I don't have enough experience to know if some new inovation is having an effect on the guitar or if it is something else in the building process. I believe I have to first get a good handle on the building process and then start to make very small changes to understand how everything effects the whole. As Others often say "it's in the details" and untill you can controll all the details so that you know that the inovation you are trying is what is making the difference you are really just playing around. For me I need to have an established product before I modify it. Of course, if you are someone who has to do something different just for the sake of being different go for it. You will have no way of knowing if what you have done has had a positive or negative impact on the final product since you have nothing to compare it to but it will be different. arvey38563.4681828704

Thanks for the info Don.

Well then guys.

I have no money to start building a guitar right now, but I will be soon. Seeing how this is the case I am just putting my efforts towards research and checking things out. If you do not like the design, then that's fine. It is a harmless question. I have some ideas kicking around and I wanted some educated opinions from those who have built guitars and have experience building a guitar about how it might sound. Perhaps with your knowledge you might be able to shed some light.

Because I haven't built a guitar yet does not mean that I am not capable. I am aware of what is involved. Seeing how you don't know my capabilities. Who are you to judge?

I was just looking for replies like "it would not work, or it could work or etc..."

I am not trying to be different. This is just stuff that I have come across in my research. Macaferri (sorry if the names wrong) did it years ago. He made a similiar design. I see it as being logical (to create volume), but maybe not, so I asked you. Maybe you have tried or know someone who has. Your replies are not very helpful.

I SHOULD HAVE BEEN MORE CLEAR with my inroduction to the picture. The basic design is a double sound board. What I saw as being logical is: if one sound board produces the sound, then why not use two. I basically thought that this would increase the volume of the guitar. The top sound board (I thought) could have a little less bracing and be able to vibrate more freely, because some of the tension would be given to the second soundboard, and at the same time also produce a vibration ftrom the strings.

Cheers

Bill

billb38563.4911111111

Not a post.billb38563.4821412037

I haven't built my first yet, but I am a physics instructor. The thing that strikes me with two sound boards is that if they don't vibrate at the same frequencies there will be cancellation of the sound. I certainly haven't done it but I have doubts. That doesn't mean YOU shouldn't experiment.

Ron

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[QUOTE=WalterK] I agree with Highdrawlicks...100%
This Forum is about sharing great ideas and skills relating to guitars in a more conventional theme.
Walter[/QUOTE]



Not to pick on you Walter.... But, Really? You think? While I agree that BillB's ideas might be a little "out there" I think it is just misplaced enthusiasm, and perhaps a bit of being different for the sake of different.

However.... I think to go so far as saying that we are trying to focus on "traditional" guitars is selling ourselves a little short, don't you?

True, we do talk about conventional designs, and small design changes such as tucking braces, or not tucking braces seems radical and inspires debate and intellectual argument. But I think to make a blanket statement that says we only do traditional is perhaps lopping of a lot of potentially innovative ideas.

Don't you?

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Bill: I see a few potential problems with that theory. First, there's the fact (as Ron pointed out) that if you're not careful about tuning the two tops appropriately, you might get frequency cancellation rather than more sound. If you're lucky, you might get a kind of 'reflex couple', which some believe can reinforce particularly the lower frequencies which a guitar, by nature of it's size (A-0 helmholtz resonance usually around F#-G) doesn't necessarily 'like' making. The back's tuned to the top, and they reinforce the lower frequencies (Al Carruth, please chime in if I go way off base here).

I'm no expert on Macafferi guitars, but I do know they're very different animals, and the double backed ones didn't have the strings attached to them. There's less tension on their pliaged (kinked, basically) tops, so they're not always the loudest on the block. I'd think a steel string guitar, traditional style, is more than loud enough as it is. Besides, is it really volume you're after, or tone, complexity, etc? And we talking steel string or classical, btw?

Finally, perhaps most importantly, there's the simple fact of mass and string pull. There's simply no way I can envisage that'll make the weight of your two combined soundboards much less than (optimistically speaking) 1.5-1.6 times the weight of a single board. Less than two normall braced tops? Potentially possible. However: you've got a lot of downward and straight upward string pull in this design; the strings are pulling at both boards (well, pulling up on the lower, pushing down on the upper) significantly. The upper board will be, far as I can see, taking close to the same amount of tension it takes anyway longitudonally, and additionally will have a downward stress not present in traditional pinned or pinless bridges. This isn't really like a tailpiece, where you would get less torque on the brige; here, you've still got quite a bit, and you'll need to brace for it. For the lower top, you're pulling straight up, or almost. That's a LOT of tension. Tops will usually flex under finger pressure, up and down, never mind putting even a portion of 200lbs of string pull on there. Try to build them light, and the whole thing will collapse, I would guess. Normal soundboards take most of the force along their long axis; even a tall bridge and/or saddle can significantly increase the torque, and lead to earlier dips, and change the sound as the force acting on the top changes.

Back to the simple fact that you'll probably end up with (taking the above conjecture into account) easily the equivalent of 2 soundboards in weight (most of the weight is the top, not the bracing), and that you'll need to design with the changed forces in mind, strings, as Al Carruth put it elsewhere, only have a certain amount of 'horsepower' to pump into the top. Many feel that Jumbos, for example, particularly J-200s and their ilk, are very much pushing the limit of what can effectively turn string vibration into sound. In fact, I've not infrequently seen comments on how smaller bodied guitars can often be louder (although may not sound as 'boomy', bassy) than their bigger counterparts, simply because of the relationship between mass, surface area, and vibration. Hopefully Al Carruth will chime in here, since I've promptly forgotten what precisely that relationship was.

That's my random theorizing. Keep in mind I don't have a lot of building experience, but I've been keeping up to date with the 'reading' side of this stuff quite well, for quite a while.

My question to you is this: what is it you want to get out of your guitar that you can't get out of a more traditionally constructed instrument? I, for one, don't see much point in innovation for the sake of being 'different', but that's just my feeling on the subject. First I want to get to the point where I'm building fairly traditional designs (albeit my own body shapes, my own bracing, my own appointments) and getting the sound I want out of them. If I get stuck, I'll 'innovate', try something different, or if I think the innovation adds value (for example: I'm thinking of an adjustable neck joint a la Doolin on my next, I'm using the Wedge design on the next few as well, ditto sound ports, and I'm pondering an arm rest or two). If being 'different' is enough motivation for you, go for it, but I do urge you to think it through, and think about the ultimate aim first and foremost.Mattia Valente38563.5411805556

Brock,
I'm not sure why you chose to single me out for criticism?
I said nothing wrong!
I respect the right to free speech here on the Forum.
Criticise away!

Not that there wouldn't be obsticals to overcome, but an exoskeleton guitar might be fun to play with. That is with regard to how changes in bracing might effect the sound.

Billb your reasons for a double top don't seem to be anything that wouldn't be solved by a trapeze tailpiece, maybe with the exception of downward pressure on the topplate.

Someone in history, I don't remember who, built a guitar with a "wing" inside. Kind of an effort to have a second lighter more flexible/responsive top. Maybe someone here knows more.

Hope you didn't take what I said as Critisism. I was speaking about my own experience. As you wait till you have the money I agree, do all the research you can. I would be inclined though to try to find as much as possible about how to get as much as possible out of the guitar using traditional and non traditional techneiques. By that I mean use traditional designs but research as much as you can about tap tunning and air chamber resonace and read up as much as you can about helmholtz resonance (I read about this but still barely understand it), You also need to learn as much as you can about the effect that weight has on a top, bracing patterns and their effect, the qualities of various woods and finishes etc. As far as the two designs you have presented so far I really don't know what effect they would have, I am skeptical but can't articulate cleary why. The selmer/Macafferi style guitars (which I know very little about) work well but they are a different beast that sound very different. If you want a guitar that has that sound why not use the designs that are currently out there to produce that sound. Lots of research and Testing has been done on selmer/Macafferi type of building methods and plans and books are available to build from. But as has already been pointed out you have to decide first what you are trying to accomplish with the guiar you plan to build. By all means though, research and ask questions.

[QUOTE=WalterK] Brock,
I'm not sure why you chose to single me out for criticism?
I said nothing wrong!
I respect the right to free speech here on the Forum.
Criticise away! [/QUOTE]

I wouldn't call it criticism... more like "friendly disagreement"... and even possibly something to spur a conversation.

I really wasn't picking on you as much as what you said sparked a thought.....   

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

There are actually quite a few strange devices in the history of guitar making that people have tried, loyd Loar, John Dopyera to name just two. While most never live up to their designers expectations some do, and isn't that the way of most inventions. I say go for but post pictures.

You may think about making the inside soundboard smaller than the top one and leaving the upper bout clear. Maybe a change in the size or location of the sound hole too.

Think about what kind of sound you are looking for and then think whether your design might make that happen.

There is a guy right down the street from me that is trying to build a classical guitar with a resonator. If that don't P$#s some people off then I don't know what will.

ps, Bill, don't let'm bully you around. This forum is for talkin about building guitars(.) If anybody is too busy to read your post then they won't.

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Tickle your guitar daily, and it'll tickle you back.

They all seem like valid quiestions to me. You should have heard some of the questions I was bouncing off John Hall when I was I getting ready to start. . Nevertheless, it is a good thing to start with that much enthusiasm.

Bill, I assume that after your first post this design is also related to nylon string/classical guitar. If so, you are going to have less energy available to drive one top more less 2. However, you might want to check out the double top guitars built by folks like   Randy Reynolds or Kenny Hill. There is lots of information out there so good luck with your search and your build. Good or bad let us know how it turns out.

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Don Atwood
Arlington, VA

wow guys. Thanks for all the great replies.

Mattia Valente thanks for taking the time to write such a long and informative post. I will be building a classical guitar. I guess the way that I see it is: Most guitars are build the traditional way which gets proven results and that is fine. I just have some ideas that seem logical to me at this point in improving loudness of the guitar and keeping the tonal quality. For example: from what I have heard a ten string classical has more of a piano sound, which I can here in Yepes recordings. My question would be to myself, "What modification could be made that would give it a sound more similiar to a six string classical guitar. From what I understand the bracing on most of these 10 strings are the same as a six string.

With some more experienced people I thought that they would be able to understand the process and what I'm trying to do. My mistake. I guess you could say I am a little over enthusiastic about it, but I also saw it as logical. Perhaps I will tone down my creativity until I have become more aquainted with the process and as result be able to solve these issues for myself.

Thanks for the suggestions John How.

Hey Don.

I have checked out some of the double tops that are being created by using a sort of beehive pattern and then laminating the pieces on the top side and under to make it lighter. The thing that I have with this is: right now I don't know how to make that beehive pattern or where to obtain it. I've thought about it. I would have to do some more reading.

Thanks RCoates. I'll look into those things you mentioned.

Bill

P.S.
To point out to some, if you see my posts as a waste of time, than please don't reply. I am not trying to waste your time. I am also here to learn.

billb38563.9824768519

As I recall, LMI was selling Nomex for double tops at ASIA. You might try them.

Great thanks Jerry. I'll check it out.

Hi Bill,

I've recently finished my first guitar, it took several hundred hours, plus another several hundred hours waiting for the glue to dry, making jigs etc. So the thing that strikes me about your posts (and never be afraid to have a new idea BTW), is that you'd spend a lot of time working on a guitar that might not workout very well (or it might work, who knows?). This could be very discouraging to a first time builder. Far better to start out with a success under your belt.

But, the more you build, the faster the build time will become, once you are jigged up, and have learnt all the basic techniques, you'll spend much less time on each guitar. This would be the time to start playing around with radical ideas - when a failure isn't going to cost so much of your time, you can learn your lesson and move on to your next idea.

Bill I think its cool to think outside the box. (or would this qualify as thinking inside the box?) Just remember that when you do that and then ask instrument makers (who are frequently a little conservative when it comes to design) for their reaction your idea might be in for some criticism.

I have seen some wild stuff passed off a guitars. Stuff that would make the exoskeleton or the double top ideas you have here seem tame. Once made these instruments had a legetimacy that they did not possess on paper. Whatever you try, do it well.

That said, I agree with the post concerning the finite amount of energy available in the strings. The strings probably have less energy than a single top can handle and adding another top would not help matters.

I really like the idea of making an exoskeleton guitar for experimental purposes. I may do that just to play around with the bracing.

JohnJohn Kinnaird38564.2777199074

I think you speed up for a while, but then slow way the heck back down once you start fiddling with more complex detailing as your skill level increases. At least, that's what's happened with (some) of my electric projects. 'course, if you're an 'essentials' kinda guy, and don't go for the abalone trim/complex inlay thing, it's not quite so true, but getting those mitres perfect, getting that carve just right, finishing those frets perfectly, nailing the bridge shape and pin fit, and setting the action exactly where you want it can be pretty darn time consuming. Even after you've built the forms and jigs.

[QUOTE=John Kinnaird] Just remember that when you do that and then ask instrument makers (who are frequently a little conservative when it comes to design) for their reaction your idea might be in for some criticism.
John[/QUOTE]

Ya thanks John. I was not aware of that. I am a member of a fairly supportive and open classical guitar forum. I didn't think I would get such a reaction. Haha.

This post has been very useful. It has provided me with a lot of insight.

I'm aware of the results that such an instrument might have and I'm also aware of the time that is involved in building an instrument. I have wasted my time in less productive ways in the past. This wouldn't really be less productive, but more like a learning experience. Like this thread has been. I'm not going to dive into something like that for my first guitar. It was just an idea that I had, that I thought might have a good effect on the volume. Obviously I have some more to learn.

The bridge is something I would do though.

You see guys you just saved me a lot of research. Thanks. billb38564.3544444444

Bill,

I'm thinking more of a "mechanical" problem you would have w/ that design. I can see from the rear trap door how you would tie the strings at the inner bridge, but how do you propose passing those limp classical stings up through "holes" (?) into the upper bridge? Will there be some tubes that guide the strings? (More weight.) An extra large sound hole to reach inside and manually guide the strings into the upper bridge? What's your thinking on this?

Steve

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