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Talking steel string and let's say OM size - No tone bars, no fan bracing, but built with a more structural (stronger/larger/thicker?) bridge plate and 'X' design perhaps?

Reinforcing diamonds or ??? for the lower bout top joint to prevent future splitting but no bracing. Thicker top but wondered if there's any builds out there that have ignored the lower bout bracing and succeeded.

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Thank You and Best To All

Not personally, but - http://www.brunner-guitars.com/?page_id=387

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

You may want to check out Kevin Ryan's Acoustic Parallel Plate - http://www.ryanguitars.com/Innovations/KRG-Innovations-APP.html

The lower bout still needs some reinforcement, but that can be achieved a variety of ways as you suggest.

Josh

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Josh House

Canadian Luthier Supply
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House Guitars - Custom Built Acoustic Instruments.
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Thanks for posting that, I was just having the same thoughts as the OP as I am building an OM and I'm wondering if I really need both tone bars.

As always this forum is an amazing source of information.

I'm experimenting with a curved bridge plate with matching curved PMTE (Proulx Magic Tone Enhancer) that seems very, very strong and should, in my mind, add a lot of resistance to any lift behind the bridge and I just got to thinking that if that area were strong enough the lower bout braces would not serve much purpose.

Further thinking makes me wonder what kind of structural help lower bout braces add any way? Fan braces I can clearly see the benefit - tone bars? Always wondered.

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To keep the top stiff and inhibit vibration? Structurally that's all I can think of outside of reinforcing the soundboard joint.

My OM style guitars only have one finger and one tone bar.

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Old growth, shmold growth!

Thanks Larry I have been leaning towards two finger and one tone bar for mine as well. Looks like that's the way I'll go, especially after seeing yours.

This is on my to-do list Small steel string with only the upper transverse brace and a very light X brace. Probably 14" lower bout at most. Anything more would probably get too heavy, since the whole point is to leave the top a lot thicker than usual and study the opposite extreme from the thin plate/heavy bracing style. I suspect I'll be doing a lot of perimeter thinning.

Mine will probably be 12 fret, so the bridge-to-tail span is shorter.

The bridge plate is a good variable to play with in this style. Mine will probably just be a small strip to protect the top from the string ball ends; no stiffening purpose. The thick top itself should be plenty to prevent bellying. But going thinner on the top, and then stiffening the bridge area by means of a large plate, should be good too. I guess mine will be more or less the same stiffness distribution as that anyway, after perimeter thinning.

And of course there's the variable of string-height-at-bridge. 1/2" is the generally accepted sweet spot for the usual designs, but I'll probably do .375-.400" on my X-only guitar so I can do lower stiffness.
...dang it, now I want to get started on this thing, but I already have too many other builds I'm procrastinating on Not to mention it's still too humid to glue anything anyway.

EDIT: Oh, and it definitely wouldn't hurt to include a crack catcher or two. I'll probably just do one going across the lower quadrant, similar to my fan-less nylon string guitar:

Proper thanks due guitarwhisperer Joey.

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Interesting Dennis. I'm thinking there must be a couple of examples out there - maybe even some old time guitars before tone bars were implemented? I'll try something I'm sure on my next OM size. Maybe short scale to start and check string tension/deformation.

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I built an OM with no bracing. That was in '95 and I still have it. Long story though because it is sandwich construction and technically more like "contintuous bracing". It rings like a piano.

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Ken

My guitar teacher, who studied with Somogyi, built a guitar some years ago for a well-known LA studio guitarist.

Apparently, even though the guy was really happy with the sound of the guitar, there was a wolf tone and this was
a big problem when it came to recording. It was remedied by adding an additional tone bar on the treble side.

Evidently tone bars aren't just for structure.

Ken, is this in a good way and would you do it again?
Thanks

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Jim Watts
http://jameswattsguitars.com

That's a pretty hefty clamp Dennis.

Steve

I would advocate it as one method and can testify that it structurally works. As stated though braces help create a voice. My braceless top is similar to a lattice style pattern in that it is a sandwich of skins and light core. A lattice is essentially th same. I have come to prefer a different sound than the brassy and punchy sound of my braceless guitar. So I probably won't be building another.


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Ken

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Ken

And the reason that it works is that it is strong and light but not equally so in the usual bracing pattern area of the lower bout. The core tapers in thickness which varies the stiffness.


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Ken

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Ken

A cautionary note though. Braces mitigate seasonal movement of the top which can raise and lower the strings.


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Ken

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Ken

Does a ladder braced guitar count? If so - then lots of people have... It was the prominent bracing scheme for most of Europe for a long time....

Thanks Ken. I've thought about that approach for many many years, I had no questions structurally, just concerned about how it would sound. Your post helps me a lot.

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Jim Watts
http://jameswattsguitars.com

Same here Ken. Hadn't really thought about the sound implications but I'm not a big fan of the old timey (ladder braced?) sound so instead of structural support for the lower bout a system the modifies the tone in a way that's pleasing to one's ears seems pretty smart - hey pretty much like tone bars?

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Todd,

Thanks for the information and first hand experience. I think that without a more thoughtful approach just leaving off the tone bars/lower bout bracing because one can may not create a 'good' sounding guitar.

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Thank You and Best To All

In the top brace system, most of the weight is in the top and most of the stiffness is in the braces. Get rid of the braces and the top has to get thicker. This makes the system weigh more for the same stiffness. Responsiveness is generally reverse proportion to the weight. More weight, less responsive. Certainly no free lunch and how you build depends on what you want to get out of the guitar. Smaller guitars can have less bracing, but there is a limit. Just my opinion of course.
Tom

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A person who has never made a mistake has never made anything!!!

What got me wanting to use one tone bar and 2 finger braces was my design, it's a bit smaller than most OM's and it just didn't look right with all the bracing. There's not much room in this box at all compared to a dread. I'm going to give it a try, worst comes to worst I'll add another brace.

Larry,

I am in the throes of experimenting with triple-top sandwich tops with two thin spruce outer plates and a laser-cut thicker center plate.
I have one instrument built this way so far, but the sandwich was not quite thick enough - I had to add one cross brace just below the sound hole to stop the top from caving in above the bridge.

I have a second instrument nearly finished that has a thicker sandwich that shouldn't need any braces at all. Should be done in a few weeks. Look out for a posting from me on that....

As far as sound goes, based just on the first instrument, I'd have to say it's an acquired taste. It has fantastic sustain but sounds kind of "muddy" to me (compared with both a Taylor 814CE and a Martin Dred that I keep around for just such comparisons). I'm not convinced that I like it yet. When I get the second one done, I'll try and make an A/B/C sound comparision recording....

Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"