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Maxmimising soundboard area around bridge
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Author:  Nick Royle [ Fri Nov 22, 2013 9:21 am ]
Post subject:  Maxmimising soundboard area around bridge
I often look at my last build [the L-00 in my avatar] and think if I were to make it again, I'd make it a 12 or 13 fretter in order to "move the bridge down" and maximise the soundboard area around it. It seems like a lot of 14 fret guitars have very little soundboard between the bridge and the soundhole, whereas classical guitars have much more, and it seems like a waste of potential.
Attachment:
bridge---soundboard.jpg

I can see that without ridiculously long scale lengths, it is difficult to do this without losing access to a fret or two, so on the dred I'm designing at the moment, I was thinking of advising the "client" (my brother :)) to go for a 13 fret neck and potentially make some use of this wasted potential.

Is it a legitimate worry? Have I got something wrong here? Will it make a real difference? [probably a terrible question]. Is the area behind the bridge more important than that ahead of it?

The only con I'm really giving him at the moment is that it would be difficult to play "Sunshine of your love"! :)

Thanks in advance for any comments/advice!
Nick
Author:  Nick Royle [ Fri Nov 22, 2013 1:03 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Thanks for that, Todd! Gives me some context. I did draw a 14 to body dread [loving that g-thang] with 19 frets so as to shift the soundhole up, but it just seemed like there could be more. All designs that maximise the vibrating area around the soundhole appeal to me: 12 fret, soundhole-less, even kasha [please no projectiles :)]!

Interesting comment as to what you would or wouldn't redesign. Forgive my ignorance, I'm certainly not questioning anyone's judgement, but it seems like having a board with more raw area and making that as efficient as possible would be a nice third alternative. I expect my limited knowledge is the problem, I still have the idea of a "rocking bridge" in my head despite being told it's more complex than that. I need to buy some serious, advanced books. I'm desperate for Trevor Gore's book, and The Responsive Guitar would be nice as well. I suppose bridge placement and its effect is documented in such resources.

Talking of making a top as efficient as possible, I'm trying to decide how to do that with a tiny top I'm working on at the moment. 360mm long and 270mm lower bout, so getting it to move enough seems like a huge challenge. Wish I had the books I need to help me make such decisions!
Author:  Alan Carruth [ Fri Nov 22, 2013 1:26 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Although there may be some theoretical gain to be had from putting the bridge in the center of the lower bout, I think that, in practice, you can shift it around quite a lot without losing much. It's more about how you lay out and profile the braces than the geometry of the bridge and top, although, obviously, you do have to design around the bridge location. I once made one with 14-fret neck and a 20" scale length: the bridge ended up about 2" below the soundhole. It sounded fine, although it was hard to play in tune with such slack strings. It definitely had 'forward shifted' bracing...

In some ways small tops can be more efficient than big ones. As you decrease the span of the top you can lighten up on the thickness and the bracing while still preserving the needed stiffness.It works out that, if you're optimizing things reasonably closely, the mass of the top goes down faster than the vibrating area of the top, and you can end up with a louder guitar. Big guitars do tend to be more bass balanced, of course, and that makes them sound more 'manly', but they aren't necessarily more powerful than small ones.
Author:  Nick Royle [ Fri Nov 22, 2013 1:43 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Thanks, Alan! Very interesting. Out of interest, would the slack strings/playing in tune issue on that guitar be solved by tuning it up higher?

And that's good news for me about small tops. I need to try to be more scientific when "voicing" this one. I'm don't think I can do much more than aim for a 2mm top, feather the rim edges, and then play with the braces... Actually, I've kinda just followed plans on my first two, and not tried to "voice" the top at all. I'm going to try to read as much as I can online to prepare myself.
Author:  Trevor Gore [ Fri Nov 22, 2013 8:15 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Nick Royle wrote:
I need to buy some serious, advanced books. I'm desperate for Trevor Gore's book, and The Responsive Guitar would be nice as well. I suppose bridge placement and its effect is documented in such resources.

Yes. They give differing views, though! :lol:

The vast majority of my SS builds are 12 fret cutaways, so that probably tells you what my preferences are! Also, to Alan's point, yes, most guitars are too big for their own good.

Anecdote: I came across some old Martin publicity stuff recently, pre war, depicting the 00 as a massive guitar with huge bass (I think it was Martin's largest offering at the time). Funny how things change! I still think that if the 00 was the only guitar model left in the world, not many people would complain once they'd got round to playing one. Notice also that 00's are essentially the same size as standard classicals. There's a message in that.

Only 4 weeks to Christmas....
Author:  Nick Royle [ Fri Nov 22, 2013 10:04 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Your anecdote got me wondering what the average new guitar will be like in 80 years...

I really love the 00, it does seem like the perfect size to me. I'm assuming though that you think dreads also have their place? Main reason my brother and I are thinking of going with the dread shape for his guitar is to make best use of the beautiful grain in the ziricote back, and to help give the guitar a big bold sound to match the big bold figure...
First first draft (just to show off the wood really! :):
Attachment:
ziricote-2.jpg

Quote:
Yes. They give differing views, though! :lol:

:lol: As if I wasn't confused enough! Only kidding, can' wait to read!

Quote:
The vast majority of my SS builds are 12 fret cutaways, so that probably tells you what my preferences are!
That helps me makes m'mind up! I won't be doing a cutaway because I couldn't bear cutting off a section of the beautiful ziricote, so I reckon I'll go with my original gut feeling - 13 frets - assuming my "client" agrees.

Quote:
Only 4 weeks to Christmas....
I've made sure the whole family know what I want for Christmas! :D
I put it on my list to Santa, too, but the other day I overheard someone saying he isn't real?! I must've misheard.

Thanks, Trevor!
Author:  Trevor Gore [ Fri Nov 22, 2013 10:51 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Nick Royle wrote:
... so I reckon I'll go with my original gut feeling - 13 frets - assuming my "client" agrees.

The advantage of that is that not many people will be able to "borrow" it, because 13 frets takes some getting used to. I find 14 a problem because I hardly ever play on 14 fret necks! Amazing how you take your cues from the body join.

Nick Royle wrote:
I'm assuming though that you think dreads also have their place?

Sure. Gotta say I'm not a big fan of Ds, though. Often thought of as an all purpose guitar, there are other sizes that fit that bill better. Strung with 13s with a flat pick in your mitt, they're a barrel load of fun. If you want to try "big", see if you can get your hands on a Collings 12 fret D.
Author:  Nick Royle [ Fri Nov 22, 2013 11:50 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
It's rare I venture down that far to be honest, not much of my repertoire calls for much beyond the 9th fret! My brother's even less so. I'll have to put the case to him and see what he wants to go with. I know he likes the L-00 I made for my dad but I can see him really enjoying having a massive (or even "manly", as Alan put it) sound at his disposal when showing it off!

I've been listening to lots of dreads since starting to think about this one. I'll have to go up to Denmark street and see if there's a Collings so I can hear one in person. Then I just have to work out how to make mine sound like it!! eek A big part of the decision is whether or not he wants to reach his arm around such a big guitar. (Although I did draw that shape a little narrower than standard - In fact, I wasn't much of a fan of the look of dreads till I started drawing that one the other day. The shape is growing on me.)

13s + flat pick x "big" dread = awesome fun and just the sound that I think this wood should have!
Author:  Alan Carruth [ Sun Nov 24, 2013 5:09 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
One thing that really helps on a big body is a 'Smith' wedge (patented in 1969, before Manzer started building, I believe). It doesn't take much taper to make it a lot more comfortable, and so long as you deepen the treble side as much as you make the bass shallower, the sound won't suffer.

Dreads have a characteristic sound; to me they tend (TEND; it's not an iron law!) to lack mid range, and it can be tricky to get the trebles to be clear. I find a well made Jumbo to have better balance if you want the 'manly' sound. I think it is at least partly due to the waist, or lack of it.

Having read both the Somogyi and Gore books, I'd say go with Trevor's, but that's just my way of thinking.
Author:  Clay S. [ Sun Nov 24, 2013 5:46 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
"It's rare I venture down that far to be honest, not much of my repertoire calls for much beyond the 9th fret! My brother's even less so."

Go with the 12 fret Dreadnought design if you don't need the high fret access. The longer body gives a little nicer sound (IMHO).
The loss of mids and trebles and added Bass makes the dread a good guitar for accompanying singers.
Author:  Nick Royle [ Mon Nov 25, 2013 5:15 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Quote:
Having read both the Somogyi and Gore books, I'd say go with Trevor's, but that's just my way of thinking.
Thanks, Alan, it was first on my list! In fact, I have a feeling Santa got my letter! :D Hopefully ordering within days! bliss

I know there are no hard and fast rules but some of this talk of dreadnoughts is worrying my slightly... The ziricote I'm going to use on this guitar almost dictates a dreadnought shape. It's like the wood is speaking to me, or shouting "don't you dare cut away my beautiful grain around the waist". Even a Taylor GS-style would clip this section of grain. And it isn't big enough for a Jumbo. My brother has just ordered an equally beautiful bearclaw "moonspruce" top to go with the ziricote and I have a feeling even that wants to be a dreadnought.... Decisions, decisions...

I'm tempted to go with my gut, if that isn't crazy, and what I think the wood is telling me and just try to make a dreadnought with the most efficient top I can manage. I've certainly played Martin dreads that I absolutely loved and I'll make my brother a small "parlour" guitar another time for something on the other end of the spectrum.

I would like the "wedge" idea for this, once again, if it weren't for the grain of this wood. If it were plainer then I'd do it for sure but I think it would be a disservice to the grain. We are considering an armrest bevel though.

I'm going to have to study the book hard as soon as I get it and, hopefully, with a little help, try to work out a plan to get the best sound out of this wood and shape!

Thanks, Clay, I think it's between 12 and 13 at the moment. Still much planning to do!

The biggest reason I haven't wanted to build a dreadnought till now is that it is the most "common" guitar, as it were. Nothing to do with the sound! :lol: I'm happy with it being a bit of a beast rather than an all rounder.
Author:  Trevor Gore [ Mon Nov 25, 2013 5:31 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Nick Royle wrote:
.... Decisions, decisions...

There's always the Gibbo J185 shape (medium jumbo), which, done right, can also sound huge and would be my preference over a D or J200. Then again, why not your own shape?
Author:  Nick Royle [ Mon Nov 25, 2013 5:43 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
I am having a lot of fun drawing shapes in G-thang, and I need to try the other program that you recommended in another thread the other week. I wish I could import a photo of the wood and accurately design around the grain, but I'll just have to do the best I can exporting to Photoshop. I wonder what I could design to keep the waist grain but avoid the disadvantages of a D shape; I know Alan mentioned the lack of waist could potentially be one the disadvantages so maybe it isn't possible.

Maybe I'm going about this wrong and I need to let go of my feelings about the grain and just choose the best shape for the job. I'll do some mockups of different shapes and sizes based on the J185 and see!
Author:  Clinchriver [ Mon Nov 25, 2013 5:54 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
OO or a 13 fret Nick Lucas special. We had our East Tennessee Luthiers Guild meeting a couple of weeks ago and got to hear both my latest builds from five feet away to across the room, simultaneously. The little Nick can more that hold its own on volume and bass. The other is a D-18 red spruce topped built to a tracing of a 1937 Martin with medium strings its a real monster. But again the smaller body really did not give up anything. I like it.
Author:  TimAllen [ Mon Nov 25, 2013 9:13 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Regarding moving the bridge into the center of the lower bout to increase bass: this is discussed by Somagyi on page 98 of The Responsive Guitar. He writes that when he first began he thought the the placement of the bridge lower on the soundboard would result in a stronger, deeper sound, but instead they produced a sweeter, more delicate sound. He believes that the reason for this is that the steel string guitar's active vibrating plate is between the upper transverse brace (UTB) and the tail block. The typical 14 fret guitar bridge is about half way in between these. It looks as if moving the bridge down puts it in the center of the vibrating plate, because that puts it halfway between the soundhole and the tail block. But the vibrating plate extends up to the UTB in the upper bout.

I think Somogyi may be on to something. Certainly, to my ear, the 12 fret Martin "S" dreads do not sound dramatically bassier than the 14 fret ones, even though the bridge is moved down and the internal volume is larger. They sound different, but not like powerhouses.

I agree that a lot of dreads have a hole in the midrange--my theory is that's why they are so popular with so much of the public, who probably have never heard of Bluegrass. The everyday player uses the guitar just as a backup, singing while playing simple chords. The hole in the middle of the range leaves a perfect place for the human voice, so the overall balance is pretty good. This makes the typical dread a good guitar for accompaniment. For solo guitar playing without any singing—the favorite music of .00013% of the public, primarily solo guitar players and luthiers—we want a guitar with a balanced sound on its own, with bass and a high-end sparkle but also a strong midrange and upper midrange. (BTW, I'm a member of this segment.)

I love the sound of an 0 and an 00 guitar. I think the old Martin PR that Trevor is referring to is some1898 catalog language, which can be found on the wonderful vintagemartin.com site. I thought this was so cool that I posted it the other day on the MIMF. My apologies to readers of both forums for the repetition:

“The sizes are recommended as follows: No. 2 ½ for young beginners; Number 2 for ladies or wherever a clear, even tone of moderate loudness is wanted; Number 1, being strong and balanced, for general purposes; No. 0, for concert playing and club use; No. 00 for exceptional power. All these have stood the test of time; they have the proper proportions and are, each in its place, the best models known. No. 0 is the most favored one, combining with great brilliancy a clearness even to the last note which is the wonder and delight of all. Similarly No. 00 adds to a heavy bass the same rich treble, and becomes thereby, a rare thing in large guitars, as well suited for solo work as for accompaniment.”
Author:  Nick Royle [ Mon Nov 25, 2013 10:52 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Thanks, Tim, very interesting to hear Somagyi's opinion! Nice to read that Martin guide to sizes, too.

And, thanks, Clinchriver, here is my latest G-Thang drawing... 13 fret to body, 24.9" scale, 20.5" body length, 15.4" lower bout, 10" waist, 11.7" upper bout. So 1/4" longer than the J185, with a narrower lower bout but slightly wider waist, I'd make it the same depth (4 7/8"). Quite a decent looking bridge location, and just about keeps the grain feature I want. More a "slightly bigger OM" than a "smaller jumbo".

Still a long way to go so many revisions to come I'm sure. Father Christmas will be here in 7-14 days [that's right, he comes early to good little boys ;)] with the key to making this guitar as well as I can! :D bliss
Author:  Trevor Gore [ Tue Nov 26, 2013 6:20 am ]
Post subject:  Re: Maxmimising soundboard area around bridge
TimAllen wrote:
“The sizes are recommended as follows: No. 2 ½ for young beginners; Number 2 for ladies or wherever a clear, even tone of moderate loudness is wanted; Number 1, being strong and balanced, for general purposes; No. 0, for concert playing and club use; No. 00 for exceptional power. All these have stood the test of time; they have the proper proportions and are, each in its place, the best models known. No. 0 is the most favored one, combining with great brilliancy a clearness even to the last note which is the wonder and delight of all. Similarly No. 00 adds to a heavy bass the same rich treble, and becomes thereby, a rare thing in large guitars, as well suited for solo work as for accompaniment.”

Yep, that's the piece. Thanks, Tim. It's a classic. I was reading it in an old "encyclopaedia" of Martin guitars.

TimAllen wrote:
The typical 14 fret guitar bridge is about half way in between these. It looks as if moving the bridge down puts it in the center of the vibrating plate, because that puts it halfway between the soundhole and the tail block. But the vibrating plate extends up to the UTB in the upper bout.

I think Somogyi may be on to something....

It's not quite so simple as taking a dimension (UTB to butt) and dividing by 2. If you do Chladni patterns on the top, you'll see which parts vibrate, where the node lines are and which parts vibrate in anti-phase. Do that for 12 fret vs. 14 fret and you reach a different conclusion.

Another question to ask is "Why are classical guitars always 12 frets clear, given the wide variety of bracing styles currently used?"

Nick Royle wrote:
...here is my latest G-Thang drawing...

Nice shape Nick! I'd probably go 12 frets though... :D
Author:  WilbPorter [ Tue Nov 26, 2013 10:46 am ]
Post subject:  Re: Maxmimising soundboard area around bridge
"Dreads have a characteristic sound; to me they tend (TEND; it's not an iron law!) to lack mid range, and it can be tricky to get the trebles to be clear."
I don't have 1/10 the experience that Alan Carruth has, but in my opinion, he nailed it with that observation. Which is probably why when I first string up my Dreds and play them they sound so full. However after, listening/playing them for awhile, I get the nagging impression that something is lacking. Alan just pointed out what is lacking. Thanks for an invaluable insight.
Author:  Pmaj7 [ Tue Nov 26, 2013 11:16 am ]
Post subject:  Re: Maxmimising soundboard area around bridge
Nice shape Nick! I think the center grain pattern is the really special part of this set.

I think 4 7/8" depth is a little more than a, "slightly bigger OM". And, if you do a wedge, beware the back binding!
Author:  Nick Royle [ Tue Nov 26, 2013 1:04 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Quote:
Nice shape Nick! I think the center grain pattern is the really special part of this set.
I think 4 7/8" depth is a little more than a, "slightly bigger OM". And, if you do a wedge, beware the back binding!
Thanks, Pat! Glad you like the shape and agree about the centre grain. As much as I like the concept, I highly doubt there'll be a wedge on this one; the grain of the sides is just too lovely to cut away any more than necessary. And you're right, 4 7/8" is pretty deep. Hopefully that'll help the bottom end.

Quote:
Nice shape Nick! I'd probably go 12 frets though... :D
Thanks, Trevor! :D I've just tried it with 12 frets and the bridge location does look really good! I'll have to get my brother to play one and see what he thinks. I'll keep tinkering while I carry on with my current build; wish I could work full time on guitars!
Author:  Alan Carruth [ Tue Nov 26, 2013 1:46 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Nick Royle wrote:
"I would like the "wedge" idea for this, once again, if it weren't for the grain of this wood. If it were plainer then I'd do it for sure but I think it would be a disservice to the grain. "
??

Using a wedge body doesn't change the back to speak of, it just angles it a bit so that the bass side of the box is shallower than the treble side. If anything, the back on a wedged guitar is a little wider than on a normal one, although the difference is small enough to be pretty academic. You do,of course, end up with less wood on the bass side, but there's more on the treble so it evens out.
Author:  Nick Royle [ Tue Nov 26, 2013 2:22 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Sorry, Alan, I wasn't clear, what I meant to say is that I think the grain on the sides is something worth keeping symmetrical.
Attachment:
back-and-sides.jpg
Certainly more of an artistic consideration than anything else! And I'm keeping an open mind.
Author:  Alan Carruth [ Wed Nov 27, 2013 3:36 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Even a little bit of a wedge, a difference of an inch or so between the deep and shallow sides, makes a big difference. That reduces the shallow side by 1/2", so you're not really losing much of that figure, and you'd get it back on the deep side.

I think that the wedge is a lot easier to do than the armrest bevel. I can't figure out any way to get around hand cutting purfling channels with the arm rest, for one thing. That takes some reasonably solid tool chops to do well. The wedge introduces some complication in the binding, too, but not as much. It goes pretty nicely with one of the 'tower' binding rigs.
Author:  Nick Royle [ Wed Nov 27, 2013 4:38 pm ]
Post subject:  Re: Maxmimising soundboard area around bridge
Quote:
That reduces the shallow side by 1/2", so you're not really losing much of that figure
True, I'm probably being a bit overprotective. Until we found this set, we were set on the idea of a wedge.

I've used this kind of setup to rout for binding so far, http://www.kennethmichaelguitars.com/images/P10100964.JPG. I imagine that would work equally well with a wedge.

And an armrest bevel is certainly daunting. I want this to be his dream guitar though, so I'm presenting him with every option! Depending on what he requests, there's a good chance I'll be making a khaya "twin" at the same time so I can test run every step and get a little extra peace of mind.
Author:  Clay S. [ Thu Nov 28, 2013 10:48 am ]
Post subject:  Re: Maxmimising soundboard area around bridge
Hi Nick,
Here is my version of a fattened up OOO design. The body length is 20 inches, lower bout 15 1/4" , upper bout 11 1/2" depth 4 7/8 inches
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