Bracing

[SwedishLuthier]

Yes and no.

I have seen that design. Can’t remember the guy’s name. You take away the stress on the bridge to top joint and probably activate a larger part of the top. But the main fault is that a flat top guitar works MOSTLY (not entirely) by introducing a rotating movement in the top that makes the top acts like a air pump, rocking forth and back with the bridge as the axis. By mowing the string fixating points to the edge of the top the bridge will not act like a lever anymore and you will loose the rotating movement. Then you depend on the up and down movement (exactly like an archtop).

But on an archtop the arch, the high bridge and the tailpiece produce quite high down pressure on the top. This makes the top MOSTLY move up and down, pretty much like a speaker cone. With the described design you will not get any of that either. So we have a design that removes the rocking movement, and doesn’t produce very much downwards pressure on the top. So what makes this guitar sound at all?

I haven’t read any trustworthy reviews of this guitar, but I am very curious about the sounds. My guess is that it isn’t very loud, but even a whisper can sometimes sound good.

[Mattia]

I wasn't accusing you of anything

The reason I tread the tried and relatively safe path is, well, because I want a guitar that sounds like the guitars I like listening to. And I don't believe reading about building, about theories, will teach me enough about guitars to let me a build a really good one (and no, I cannot buy a 'good' acoustic, most of the time, for the same money I can build one for; 250 bucks will build me a rosewood guitar with a top quality Italian spruce top, and will buy me a mediocre factory instrument). There's a lot of room for variation within the set designs, and small changes can have significant effects. Once I understand that, or at least begin to, I'll consider re-thinking stuff. I may even build myself a 'test bed' guitar and swap tops around, try different bracing, that sort of thing. Maybe.

Uniqueness, quite frankly, ain't all its cracked up to be. I'm all for it, but if I want to build successful instruments, I'll stick closer to tradition. Venture further, and you've got a good marketing spiel if it works, but a lot of R&D time and test builds are required to nail a new design. And there aren't going to be many people you can get hands-on feedback from if things don't quite turn out as you expected. The vast majority of 'new ideas' I see thrown about by most people result in someone coming and saying "that's been done here, here and here already", which makes me a skeptic. Or just a curmudgeonly bastard

This said, people like Fleischman and Rick Turner (and, most of all almost, Frank Carlson) are people I have enormous respect for, and their work is fascinating stuff. And I'm sure they know the ins and outs of traditional designs as well, and understand the instrument on a deeper level than I. I'm in this to build great instruments, someday. I put my stamp on my instruments without necessarily going non-trad, because, as many have said, almost everything's been tried in the guitar world, and sound follows construction. This isn't to say I don't experiment, but I experiment conservatively; wedged body, CF struts, adjustable neck, sound ports, maybe some day an offset soundhole (although, I mean, Tacoma, Ovation, McPherson...offset soundholes), and my own take on body shapes.

Also, lattice bracing on guitars of that time? They had ladder or fan bracing, not lattice bracing AFAIK.

As for mass being directly related to volume...I wouldn't bet on it, per se. 5% ain't a lot, and it depends on the distribution of those 5% mass; my overbuilt (I really should strip it and shave the top down some, maybe lower the braces) first guitar is a very, very loud guitar when strummed. Louder than many a lighter-built guitar. There's also the issue of percieved loudness (more important than actual volume), which has a lot to do with psychoacoustics, and which frequencies are reinforced or not.

Pr3Va1l: that woud be Jeff Babicz, methinks. By all accounts, they're great sounding instruments. But not significatnly better sounding than a well-constructed more traditional guitar, nor significantly louder (or, as it happens, not any quieter). I've not seen any, but the topic's come up on a different forum, and several folks who've played a variety of them commented. Word is they sound quite 'modern'. Compressed. Good for amplifying.

Edited March 11, 2006 by mattia

[SwedishLuthier]

Also, lattice bracing on guitars of that time? They had ladder or fan bracing, not lattice bracing AFAIK.

My mistake. I meant to write ladder.

As for mass being directly related to volume...I wouldn't bet on it, per se. 5% ain't a lot, and it depends on the distribution of those 5% mass; my overbuilt (I really should strip it and shave the top down some, maybe lower the braces) first guitar is a very, very loud guitar when strummed. Louder than many a lighter-built guitar. There's also the issue of percieved loudness (more important than actual volume), which has a lot to do with psychoacoustics, and which frequencies are reinforced or not.

I have to disagree about the importance of mass in a top. I come from the theoretical side (it will be different when I have finished my current build) but I have an engineers degree and

I know some of the physics around transferring vibration into sound. The guitar is going to be measurable louder for every percent that the top is lightened. If we are going to be able to detect the increase in volume depends on, among other, the psychoacoustics you refer to. If we are going to like the sound of the louder guitar is totally a question of personal taste, which is mostly basted on what we are used to hear.

[fryovanni]

Wow, Quite a little debate.

I don't believe I have any issue with new bracing designs or experimenting. That is the fun of the whole process. I also see how moving sound holes around can change up the sound of your guitar.

So a couple questions are jumping out at me here. There is a lot of discussion about alternate bracing to reduce weight, but no talk about how thick you plan to make the board you are bracing. So just for curiositys sake how about adding the type of wood you plan to brace, and what thickness you plan to take that wood to. With the alternate bracing systems you guys are thinking about, how much bracing mass will be reduced? Will the system allow for a reduction in mass behind the bridge or primarily in front of it? Do you anticipate you will be able to safely thin the top more because of the unique bracng? All generic questions just because I am curious. I probably should read up more on the different theories out there.

As for moving and or changng the size of the sound holes. What do you want to achive in terms of the change in overall sound of your guitars. I do not believe relocating the soundhole to reduce bracing mass by itself is sensable. The voice and overall tone of an acoustic changes quite a bit by altering the soundhole. Not to say thats bad or good, just different. Just curious, I have been really interested in trying some mods to the soundhole myself.

Peace,Rich

[Mattia]

I have to disagree about the importance of mass in a top. I come from the theoretical side (it will be different when I have finished my current build) but I have an engineers degree and

I know some of the physics around transferring vibration into sound. The guitar is going to be measurable louder for every percent that the top is lightened. If we are going to be able to detect the increase in volume depends on, among other, the psychoacoustics you refer to. If we are going to like the sound of the louder guitar is totally a question of personal taste, which is mostly basted on what we are used to hear.

I'm not positive, but I wouldn't necessarily bet on it being a big difference. The measureable difference between a bad and a good guitar, lightly built and heavily built guitar in terms of pure decibels is probably very, very small (some folks on the Leftbrain Lutherie mailing list can probably give you some actual numbers) Reason being: guitars are terribly ineffecient when it comes to converting string energy into sound, so only a fraction of the percentage mass savings will translate to more efficient sound creation.

I stick by my contention: 5% savings is significant, yes, but whether it affects the sound depends on where you're getting rid of the mass. Sometimes people actually want heavier bridges, to achieve a specific tonal goal (bassier timbre; ebony bridges, f'r instance, can tend to filter out high frequencies, biassing the tone towards the bass end), without the overal volume being affected greatly. Mass itself means little. Distribution of the mass is everything. Heck, some builders prefer slightly heavier tops and lighter bracing to get the 'voice' they're looking for (a bit of extra thickness in a top adds a lot more weight than the gain from lightening up the braces), and I've never heard anyone complain they were quiet instruments.

I have to ask: Is there a reason you want to get the maximum decibels out of a given guitar? Are current designs too quiet? What goals are you trying to achieve, other than 'something unique'? Have you got a specific tonal and/or aesthetic goal in mind?

(I'm told I can come over a bit strong; I'm just in it for the discussion and constructive debate, so rest assured I ask in all friendliness, 'k?)

[SwedishLuthier]

No problem Mattia, I’m here to learn and your inputs will some way or another find its way into my guitar.

My reason to move the sound hole is not based on sound. I think that the current design with a hole in the top placed exactly were the string place the most stress on the top isn’t very clever. By moving the hole the top itself (before bracing) will be much stronger and the braces can be used to shape tone, instead of reinforcing the top. I also think that I can make the top itself quite a lot thinner because of the strait, uninterrupted fibres that bear the load. Add to that the fact that I will use a radiused top (arches withstand deflection a lot better that flat surfaces) and I BELIEVE that I can reduce weigh in a way that will make an audible difference.

I’m yet to decide if I will use a variation of the bracing system like the Ovation shoved by Pr3Va1L http://projectguitar.ibforums.com/index.php?showtopic=21483# or an offset X-bracing. The idea of an offset bracing system to help emphasis de different parts of the tonal spectrum (an idea I got when studying Kasha’s ideas) is very appealing to me. Different fundamentals have different length. Different length on the bracings ought to help delivering a broader tonal spectrum.

Having said that, I am totally aware of that it is quite possible that this “broader tonal spectrum” might not be very pleasing to hear, because we base our ideas of a good guitar sound on references we have to a lot of things. It might even be of things that have nothing to do with the guitar sound at all. Say that you got your first kiss, listening to a troubadour playing a jumbo style guitar. You will (probably subconscious) remember this kiss every time you hear a jumbo being plucked!!! Now I’m really drifting away from the subject, but it has some relevancy to this discussion.

As to the question of how thick I’m planning on doing my top (or actually how stiff the top and bracings together will be) I have an approach that I will try. It’s called deflective tuning. You glue the braces to the top. Then you put the top into a jig that holds the periphery pretty much like if the top were glued to the sides. Then you apply the same torque that the strings attached to the bridge would, and measure the deflection. Then you tune the top by removing wood, either from the bracings or from the top itself until you get the desired amount of deflection. So how do you know how much deflection that is desired? Well as a first time builder you cant. But I’m planning on borrowing a lot of guitars, both god and bad sounding, and measure how much it deflect under string tension. Then I’m going to make notes of how they sound (bass heavy, middy, woods used, dynamics in sound etc) and use this to decide how much deflection I’m aiming for.

And how about what I’m aiming for? I want a guitar that is responsive enough to answer on subtle finger picking (a light weight top would help) and yet doesn’t ”bottom out” (over compress) when strummed hard (using longer braces to activate a larger part of the top is what I think would help in that area). I would like a guitar that can deliver distinct single string bass line and cutting high string cord melodies at reasonably equal volume. I’m starting to sound like Freddy Mercury of Queen: “I want it all”.

[fryovanni]

It sounds like you have a plan and are doing a fair amount of research. It also sounds like you know what want(well everything ). I look forward to seeing what results you find. I guess I went down a different road in learning(starting with traditional designs, and modifying based on observation). I think if I was going to attempt the research you are going to do. I would saw up maybe 10-20 soundboards, and cut a fat stack of brace blanks. Build one and use what you learn to refine your building process. Then sharpen those chisels and try to produce a run with slight variatons( to test your theories). If nothing else it will be good practice.

Do you plan on building the top flat or radiused?

Well gotta run, Peace

[SwedishLuthier]

I'm going to use a 25' radius on the top and 15' on the back.

[fryovanni]

Good luck with it. I look forward to seeing what you find. I am sure it will go well for you.

Peace,Rich

[Pr3Va1L]

A good way to make tests, as mattia pointed out, would be to build a guitar on with interchangeable tops... Then tests would not be so hard to do.

Hell, that could actually be a good idea for sale... Have different tops for different styles of music, with the same guitar

About volume, there's also the perceived volume that can be misleading... With my O', I almost can't hear myself when i'm playing unless I put me head near the top\soundhole...

I suppose that means the sound is less "wasted" on the back and sides of the guitar and projected on the top, at least in theory... And btw, even with the shallow bowl, my guitar is almost as loud as my friend's when strumming, wich has a Jumbo...

Anyways, I think it's good to see great builders like you guys think about the bracing, seeing how most high end builders don't even ask themselves the question and build "good old" X bracing...

[Mattia]

A good way to make tests, as mattia pointed out, would be to build a guitar on with interchangeable tops... Then tests would not be so hard to do.

Hell, that could actually be a good idea for sale... Have different tops for different styles of music, with the same guitar

About volume, there's also the perceived volume that can be misleading... With my O', I almost can't hear myself when i'm playing unless I put me head near the top\soundhole...

I suppose that means the sound is less "wasted" on the back and sides of the guitar and projected on the top, at least in theory... And btw, even with the shallow bowl, my guitar is almost as loud as my friend's when strumming, wich has a Jumbo...

Anyways, I think it's good to see great builders like you guys think about the bracing, seeing how most high end builders don't even ask themselves the question and build "good old" X bracing...

The major problem I see with swapping tops around is simply the fact that you'd need to leave the tops on for a few months and play it to really begin to get a feel for the isntrument (if it was any good), and because you can't do a direct A-B, you'd need some sort of controllable, reproducable way of recording the instrument's voice to tape, accurately; your memory for sound may be really good, but good enough to remember exactly how a guitar sounded different after a specific change, a month or so later?

In terms of percieved volume, that's one of the reasons I want to use side soundholes (or sound ports, whatever you want to call them); most players report an increase in percieved volume; it's like a personal monitor. And to boot, Al Carruth's measurements on his test guitar indicated a 1-2% increase in measurable volume, although in real-world terms that's pretty insignificant.

[KeithHowell]

Have a look at Mervyn Davis's guitars at www.mervyndavis.com

His guitars are almost a kit of interchangeable parts. They sound great and play great as well.

Keith

[fryovanni]

A good way to make tests, as mattia pointed out, would be to build a guitar on with interchangeable tops... Then tests would not be so hard to do.

Hell, that could actually be a good idea for sale... Have different tops for different styles of music, with the same guitar

About volume, there's also the perceived volume that can be misleading... With my O', I almost can't hear myself when i'm playing unless I put me head near the top\soundhole...

I suppose that means the sound is less "wasted" on the back and sides of the guitar and projected on the top, at least in theory... And btw, even with the shallow bowl, my guitar is almost as loud as my friend's when strumming, wich has a Jumbo...

Anyways, I think it's good to see great builders like you guys think about the bracing, seeing how most high end builders don't even ask themselves the question and build "good old" X bracing...

I think it would be cool to create a testing tool. I think in the grand scheme of things the differences would be challenging to measure as there are so many variables. How would you test the soundboard? Would you want your test rim to be capable of being adjusted for in terms of depth(maybe like a free floating snare drum)? Do you make the back interchangable or just fixed?

P.S. Your comment-

Anyways, I think it's good to see great builders like you guys think about the bracing, seeing how most high end builders don't even ask themselves the question and build "good old" X bracing...

. Joke? Obviously high end builders can use other bracing systems to think otherwise would be very naive. They want to produce the best sounding instrument they can(sounding to most of the population). Reliable,predictable,stable, and really quite versatile. X-bracing is a solid choice, and is obviously well recieved. Not to put down different systems, but no other system has proven to be as accepted or reliable. We are talking about unique experimental bracing designs. We don't have to make a guitar that is widely accepted, and if our bracing fails it is only our loss. We also have an advantage because we do not have to reproduce our instruments with a high degree of consistency. Just my couple of cents...

Peace,Rich

[SwedishLuthier]

With my O', I almost can't hear myself when i'm playing unless I put me head near the top\soundhole...

In terms of percieved volume, that's one of the reasons I want to use side soundholes (or sound ports, whatever you want to call them); most players report an increase in percieved volume; it's like a personal monitor

That’s the reason why many builders that thinks outside the (sound) box move the soundholes to the sides, facing up against the player. I think that Linda Manzer even had a system with soundholes in the sides with sliding ports, so that the player could adjust both the volume coming through the soundholes, and also tuning the guitar itself.

But we have to remember that it is only a small part of the sound pressure that comes from the soundhole. I don’t remember any numbers but it in the range of 10-15% or something like that. The rest of the sound pressure is coming from the top itself. OK some from the sides, the back and so on, but you get the pictures. The withdrawal of a soundhole in the side is that the sound pressure that use to project towards any audience will now be projected towards the player. Maybe not a big problem, but worth considering before using soundholes in the side.

. We are talking about unique experimental bracing designs. We don't have to make a guitar that is widely accepted, and if our bracing fails it is only our loss. We also have an advantage because we do not have to reproduce our instruments with a high degree of consistency. Just my couple of cents...

And you are right on the money

[Pr3Va1L]

Well, I don't really see the point of those side soundholes... I mean it's ok to hear yourself, but the point of speaking of bracing right now is that we want the guitars to sound good acoustically, wich a side soundhole will not help to do...

I'd really like a side soundhole on a guitar with a piezo, where the bracing type plays a much less important role in the sound, but for acoustic sound I think you're better off with the soundhole where the poeple\mic are

[SwedishLuthier]

I totally agree with you. I don’t think that the sound of a guitar should not be projected against the player, but against the audience. I hope to come up with a guitar that is loud enough so that side soundholes isn’t necessary.

[Mattia]

Well, I don't really see the point of those side soundholes... I mean it's ok to hear yourself, but the point of speaking of bracing right now is that we want the guitars to sound good acoustically, wich a side soundhole will not help to do...

...and your evidence for this belief is what, exactly? All the data I've seen and heard, both anecdotal and from those who've made actual measurements, indicates that while sound ports don't do anything dramatic to the sound, they actually increase the output (measured from the front) rather than decrease; only caveat; put a 1" side sound hole in, you want to decrease the size of the main soundhole by the same surface area if you want to keep the main Helmholtz resonance the same. Overall output tends to go UP by a percentage point or so. What exactly these side soundholes are doing isn't clear yet, but they're not 'leaking' sound away from the top, in any event. The theory I've seen that makes most sense to me is that they're allowing some of the back-and-forth moving air to 'escape', a resonance mode that doesn't hugely affect the top anyway.

Sounding good acoustically includes sounding good to the player, IMO; I want to achieve both. The person who's got to live with the sound, listen to it, is the player.

I totally agree with you. I don’t think that the sound of a guitar should not be projected against the player, but against the audience. I hope to come up with a guitar that is loud enough so that side soundholes isn’t necessary.

The withdrawal of a soundhole in the side is that the sound pressure that use to project towards any audience will now be projected towards the player. Maybe not a big problem, but worth considering before using soundholes in the side.

See, that's the nice thing; side soundholes have been found to actually *increase* projection towards the audience, as well as providing the player with a personal 'monitor'; the guitar's output when measured from the front increases, and there's a difference for the listener as well (although it's a minor one; people hear the *change*, but a while later, the difference is minimal). The air in a guitar is moving, the whole thing is vibrating, and there are components that are directed, say, at the sides that don't necessarily contribute much at all to the overall sound. Besides, for recording, this gives you an extra interesting source to mic from Counter-intuitive as it may seem, a hole in the side does not necessarily mean you're 'losing' sound out the front, depending where you put it (most seem to prefer the shoulder of the guitar as a fairly 'neutral' location).

Particularly with certain schools of building (heavy, stiff sides, outward projection only), a side-monitor can be helpful because very little of it returns to the player; it's all directed outward. Small side ports seem to be more or less 'free', maybe even beneficial to forward projection. And honestly, as a player, I want to hear what I'm playing. I'm the one who's going to be listening to the nuances of that specific guitar, not most yabos in the audience; they don't care if I'm playing a cheap import or a finely hand-crafted, custom-made guitar, for the most part. I want to hear what I'm playing, because it lets me adjust my style to what I hear.

Edited March 14, 2006 by mattia

[fryovanni]

You know Mattia's point on the soundhole placement is interesting. Sometimes things seem like they would work one way yet the net result is not as anticipated. Acoustics are very dynamic and there are a lot of elements that work together. It is easy to draw conclusions(that seem very logical) about modifications, yet our results may not be quite what we expect. All the more reason to keep thinking and trying new ideas, but temper our expectations(avoiding absolutes).

I was about to drop a top on my current project. I ran into a bit of info about baking soundboards that caught my attension. Now I thought the idea crazy at first blush(cooking a soundboard @200degF. for an hour to simulate exposure to extream heat). However after reading further and looking at some of the builders that have been doing this with success(not to mention talking to Mattia). I figured I would give it a try and make a new board, before placing the one I had ready to install. I took a set of Red Cedar(next sequential set from the same billet as the top I had ready- both dried equally and basically as similar as one could hope for) and baked it. It was unharmed as far as I could tell. When thicknessing the top I noticed it did seem a bit stiffer and was able to thin it a bit more than the unbaked set (about .015" thinner). I braced it using bracing stock from the same pile(equally dried and such). When I had the bracing carved to the same shape and thickness I noticed the baked board still needed to be thinned even further to match the first soundboard. I guess my point here is that I would have never expected that result, and if I hadn't been able to see a comparison quite like this I doubt I would have believed it. Now until I try it a few times I can't be totally sure this wasn't a fluke, but it was interesting.

Peace,Rich

[n8rofwyo]

Where to start? I hadn't been interested in building acoustics until recently and have followed this thread - in particular - with much interest. I have been researching across the net for the last couple weeks and have come across alot of clear, concise information concerning acoustic top bracing. Unfortunately I have also come across alot of conflicting view points. Here are the two that are most interesting to me at this point:

1) Does anyone have information - whether it be anecdotal, printed, or otherwise acrued - concerning whether symmetrical bracing is more prone to producing nodes that interfere with individual string output at a given frequency? I have read that the reason for asymetrical bracing patterns is to reduce the likelyhood of having a node under the bridge. Conversely, I have come across luthiers that purposefully brace symetrically to achieve more fundamental tones with "delayed" overtones - supposedly resulting in a richer, more robust sound.

2) Arched bracing? Think Roman aquaduct. This type of bracing seems to span about an inch or so of the top before making contact with the top again. Supposedly this lets the top vibrate more freely due to less mass being attached to it. I haven't been able to find much at all on this, but the idea is intriguing and might be fun to do - that is if it isn't a crock.

Anything you could add would be helpful, TIA.

Nate Robinson

[Mattia]

Hi Nate,

1) Haven't seen anything that would indicate a node issue; Al Carruth's done a lot of glitter pattern testing, and on a 'matched pair' experiment he did (Standard and symmetrical bracing), people tended to prefer the symmetrically braced guitar. He also looks for symmetrical main top resonances, prefering even shape over a specific frequency. There's stuff on this in the MIMF.com library if you want the actual details. Keep in mind there's a sizeable population of Larrivee-trained and influenced builders, some at the very top end of the market, that brace symmetrically. Both methods seem to work, and honestly, I've never come across any references to the bracing 'messing' with a specific node if its symmetrical. If you want a vintage Martin tone, build to vintage Martin specs. Also, every Larrivee I've had the pleasure of playing was quite lovely.

2) It looks cool, but I'm not sure there's a huge savings to be had there, per se; you need a certain amount of gluing area to keep things in check. Ive seen a few Kasha-inspired bracing schemes (which all look very 'heavy' to me) that feature them, but mostly classical guitar bracing that had the fans going from top to tail, as it were, passing under the aqueducts.

[fryovanni]

Where to start? I hadn't been interested in building acoustics until recently and have followed this thread - in particular - with much interest. I have been researching across the net for the last couple weeks and have come across alot of clear, concise information concerning acoustic top bracing. Unfortunately I have also come across alot of conflicting view points. Here are the two that are most interesting to me at this point:

1) Does anyone have information - whether it be anecdotal, printed, or otherwise acrued - concerning whether symmetrical bracing is more prone to producing nodes that interfere with individual string output at a given frequency? I have read that the reason for asymetrical bracing patterns is to reduce the likelyhood of having a node under the bridge. Conversely, I have come across luthiers that purposefully brace symetrically to achieve more fundamental tones with "delayed" overtones - supposedly resulting in a richer, more robust sound.

2) Arched bracing? Think Roman aquaduct. This type of bracing seems to span about an inch or so of the top before making contact with the top again. Supposedly this lets the top vibrate more freely due to less mass being attached to it. I haven't been able to find much at all on this, but the idea is intriguing and might be fun to do - that is if it isn't a crock.

Anything you could add would be helpful, TIA.

Nate Robinson

Nate,

1) Never seen anything solid that would back any of this up. I am sure you could find someone out there that has an opinion on the subject, but I doubt you would find it to be backed by real solid data.

2) Arched bracing is or in some fasion is the basic form of most bracing. As far as seperating the brace material(top and bottom). I doubt it will cut the actual weight much, and I would be leary of sympathetic vibration(odd phasing, that could produce negative results). I would feal more comfortable knowing the bracing is moving with the soundboard. Tall bracing shaped heavily, maybe drill out some of the material(can reduce weight without much loss of strength), I-beam style or "T" bracing. All of these methods can optimise strength to weight, and are fairly simple to use. My best advice to you would be to buy some student grade soundboard material, and play with building a couple soundboards. After you build a couple you will be able to see through the muck of theories, and also spot real good ideas.

You will find people have many ideas when it comes to acoustics. Three things will hold true no matter what. There are very few absolutes(for all guitars), Superior is subjective, and if it sounds, plays, looks, and remains in tact for a lifetime(and on) your design rocks.

Spend some time building jigs,forms and tools. Sharpen your tools, and get used to tight tolerances. Round up a lot of clamps. Increase your standards for the wood you use, and become much more aware of moisture content(monitor the humidity in your shop). Get used to working with finer details. Oh... Listen to Mattia- that fella is pretty sharp.

Peace,Rich

[SwedishLuthier]

side soundholes have been found to actually *increase* projection towards the audience, as well as providing the player with a personal 'monitor'

That really gave me something to think about. I have not been fortunate enough to be able to test a guitar with side soundholes, but every time I read about them the writer have claimed the opposite!

the guitar's output when measured from the front increases

Do you have any hard facts that back up that statement? I would really like to read up more on that. Do you have any links? I have a hard time to find any god information. Let me give some examples: Here we have to slightly different opinions, one that the projection didn’t suffer much, and another that the projection suffered (ok, with a front soundhole AND a sliding panel in the side).

Here it is suggested that the projection is unaltered, but no measurements made.

At Beardsell Guitars homepage it is his "opinion" that the projection is unaltered (mind you, he’s trying to sell guitars here…), but again no measurements. I can go on for some time but the essence of this is that I cannot find any really tests that have been made. I can only find opinions, mostly stated by builders trying to sell their “revolutionary new design”.

Even though I am a little afraid that the projection will suffer, I have come to understand that a side soundhole directed towards that player has to be considered. My construction of the top is based on a cutaway Dreadnought with the soundhole moved into the cutaway area. This area contributes very little to the sound production. When moving the soundhole the distance to the player increases. It might be a good idea to open up the side to project some sound toward the player. But I am very concerned about projection and perceived sound level with the audience. Right now I’m leaning towards no side soundhole, but with a construction (extra reinforcements in that area) that will allow for a soundhole to be added after the first assembly (and testing) of the guitar. Decisions, decisions…

[Mattia]

side soundholes have been found to actually *increase* projection towards the audience, as well as providing the player with a personal 'monitor'

That really gave me something to think about. I have not been fortunate enough to be able to test a guitar with side soundholes, but every time I read about them the writer have claimed the opposite!

the guitar's output when measured from the front increases

Do you have any hard facts that back up that statement? I would really like to read up more on that. Do you have any links?

Me, personally? No. But search the MIMF, or shoot Al Carruth an email; he build a 'corker' guitar, with a bunch of soundholes in the sides that he closed up with corks, and opened at will. He's also pretty tech-minded, and took quite a number of measurements with standardized setups for plucking strings/recording them, etc. I've yet to come across a claim (my general haunts are the MIMF, Luthiersforum.com, sometimes the 13th fret and the aocusticguitar.com luthier's corner) that it significantly decreased forward projection, but it does change it; from what I've read, it increases the '360 degrees' aspect of the sound, and in some measurements the forward projection also increased by a percentage point or so. Are you on the Leftbrain Lutherie mailinglist? Google that (and/or David Hurd ukulele), and peruse the archives or start a new discussion. Lots of science-minded builders with more experience and actual hard data there.

Me, I'm going to give it a shot, see how it turns out. I'm not worried about the instrument losing projection, but I'm not planning on a huge soundhole. Something in the vicinity of 1" diameter, one location, see how I like it. My main interest is in an instrument that sounds good, that's loud enough, and that the player can hear well, because I build for players, not for audiences. And yes, I make sure it amplifies nicely, because that's the sound the audience is going to hear. The player's going to enjoy the instrument for what it is.

[DFW]

I'm just going to throw in something I've been tossing around. I was looking at a few things, specifically Ribbeke's Halfling, The Kasha/Schneider, Lattice style, and Fred Carlson's DreadNautilus and kinda got thinking this: How about an asymmetrically domed top (12' on treble and 25' on bass perhaps) braced with fanned lattice (tighter on the treble side and wider on the bass)? I'd use Carlson's leaf-bracing technique to handle the whole odd dish situation. Does that make sense? Is it straight kooky? Alls I know is I want to try it.

[fryovanni]

I'm just going to throw in something I've been tossing around. I was looking at a few things, specifically Ribbeke's Halfling, The Kasha/Schneider, Lattice style, and Fred Carlson's DreadNautilus and kinda got thinking this: How about an asymmetrically domed top (12' on treble and 25' on bass perhaps) braced with fanned lattice (tighter on the treble side and wider on the bass)? I'd use Carlson's leaf-bracing technique to handle the whole odd dish situation. Does that make sense? Is it straight kooky? Alls I know is I want to try it.

Not to comment directly to your bracing configurations, but an observation that has been really sticking with me as of late. I have been doing a lot of deflection testing on soundboards of several species(Redwood, Sitka, WRC, Hemlock, POC, Lutz Spruce, White Spruce, Engleman Spruce etc..). One thing that has really been notable beyond differences in longtitudinal stiffness, is that you really see differences in cross grain stiffness(and it is not directly proportional to longtitudinal). I believe you have to think about this if you are trying different bracing configurations. In a sense one bracing configuration may attempt to increase cross grain stiffness to a greater extent than another configuration. If the soundboard you are using naturally has a lower cross grain stiffness(and this stiffness varies a great deal) you may have done nothing more than make it comperable to a species with a stiffer crossgrain(as it relates to longitudinal). Of course asymetrical braing would still produce different stiffness across the board, so maybe that makes the cross grain stiffness less of a consideration. Alternatively it would add merit to using disimilar woods for your soundboard itself to develop different treble/bass side charictoristics.

Kinda interesting, Even though I am still in the "soundboard acts more as a single unit" camp, as opposed to those who believe the soundboard favors treble and bass sides.

Peace,Rich