Official Luthiers Forum!

Does anyone here add a brace behind their bridge plate?

The brace I'm talking about butts tightly against the bridge plate.

I've read that it "completely eliminates deformation" behind the bridge.

Also it's supposed to help the balance between the treble and bass.

And the midrange (G and D strings) response is suppose to improve.

John

If you do a search for PMTE you'll find 60 hits that talk about it, as well as some other names for that brace, which also get results.

You've been pretty public on a couple of forums about a clash you've had with the "P" part of the aforementioned brace ; Is your question genuine or merely provocative? It has the appearance of

Just something I noticed....

I think it depends on the guitar. I tried a number of variations of that on a test top several years ago and none of them sounded good to me. It wouldn't surprise me though if it helps other guitars and my guess is that it may help those with light bridges and small bridge plates.

It's not hard to try after the fact. You should be able to glue one in and pull it out fairly easily if you don't like it.

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http://www.chassonguitars.com

That's the case when the "P" person uses it too, as I recall. He adds it if it's needed, only.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I make up a PMTE for every guitar I build for installation later if necessary. On half of them I install it after a few months. It seems to really balance things out when needed.

Mario freely admits that he did not "invent" this brace. The name was made up by Bryan Kimsey who often installs the brace as part of his hotrod mods of factory guitars.

Colin Symonds has also used the brace as has at least one of the Kinnaird brothers for a long time as well.

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JJ
Napa, CA
http://www.DonohueGuitars.com

John, Why is completely eliminating deformation behined the bridge a good thing? I don't know one way or the other wether it's good or bad, just curious what you thoughts are.

Oh, I have built with the brace described by Don Muser and am pretty neutral about it, depends on the top I think. You can read his account in the GAL publication "Lutherie Woods and Steel String Guitars" if have a copy of that.

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Jim Watts
http://jameswattsguitars.com

I use something similar, but it is spruce and spaced about 1/4" behind the plate.

I don't know about completely removing deformation, I use it to help assure a my desired dome in the area between the lower x-braces.

I seems to improve the bass response.

-jd

I've experimented with something similar too, don't use it today.

Greg

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Gwaltney Guitars

Here's how I do mine.
I put the peak of this "Don Musser" brace right behind where the treble e string will be. It tapers off to the legs of the "X" on either side. It is 1/4" wide, roughly 3/8"+ tall at the peak.
I've found a balance across the range, with an increased sweetness in the trebles. I always use it.




Steve

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From Nacogdoches...the oldest town in Texas.

http://www.stephenkinnaird.com

I've retrofit them on a few guitars that I felt were a touch underbraced and felt "mushy" with a very heavy attack, and I liked what it did. I will likely do it again. It's nice to know that if you outtrick yourself in building too light that there's an eleventh hour save.

I always use it as well and have done so on some 30 guitars, but it has to be done as part of the overall bracing scheme. It is not a new technique and in fact dates back to at least the 19th century, and can even be akin to a brace often used behind lute bridges. So as with most things related to guitar making, no one around now can claim to have invented it. I wouldn't build without it as part of the scheme.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

I put a laminated one on da Big Boy...

Back in 1987 Fine Woodworking issue, Grit Laskin was using a brace behind the bridgeplate. It was 7.5mm high and 7mm wide.

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Under Compensated Nut!

I'm not at all sure eliminating all deformation behind the bridge is a good thing. I've been trying pretty hard to understand it recently and yesterday I pulled that GAL publication off the shelf and just happened to open to Don Musser's article. The quotes where his and it got me curious.

It's not so easy to get detailed information about top deformation and exactly how bracing effects it. I've asked around and only found a couple of people who ever measured it. Maybe more people do at David Hurd's forum.

I've been working on an FEA model to help me understand this and along the way I decided I needed to model the entire guitar because it seems that how the whole guitar moves is what really maters. In other words, to understand how the top moves you have to understand how everything moves.

So when I ran into Don's article I was wodering if I should put it on my on my list of things to model. FEA will give me a really detailed view of what it does and doesn't do. It will also help show how it effects the modes. But it's time and work to do.

Anyone here know Don Musser? It would be great to know how it worked out long term and if he is still using it.

John

That's the brace from the article I saw. Do you use the asymetrical X that Don mentions in the article too?

John

After seeing how many people are using it I think I'll put it on my list of things to model.

On more quesiton comes to mind. Does anyone who uses this brace also use Chladni patterns and try to close the ring mode? I'm curious if this helps or hurts that.

John

Laskin used the idea that he learned form Larrivee ... Jean started using that brace in the early 70's. Its part of his symetrical bracing scheme, and its on every guitar he has made .. I have been using that style on all my guitars.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Larrivee's are similar in that they are perpendicular to the top grain but they are much further back from the bridge plate and much larger. I think these little ones butt right up against the bridge plate.

I believe Colin S made the comment that it dates back to the 19th Century!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Hi John, no, the assymetrical X is one thing I haven't tried.
In a way it makes sense, leaving the treble leg unscalloped--to bring out more trebles--but I feel that the tone bar/Musser brace/finger brace intersection gives ample localized stiffness.
Having both lower legs scalloped is our effort at getting the entire top to work at those low frequencies.

Steve

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From Nacogdoches...the oldest town in Texas.

http://www.stephenkinnaird.com

I use one on all steels.
I got the idea from Larivee also back in the early 80's
I like the idea of keeping the bridge area stiff and the edges of the top flexible.
This brace helps with that plan.
Mike

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Mike Collins

I thickness my tops by stiffness along the grain. If the stiffness across the grain is too low then I use one of these braces. If the top is too stiff across the grain (or if one of these braces are used, and shouldn't be) the tone tends to get kinda one dimensional........at least to my ears.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Woody, one dimensional as in emphasizing treble?

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Formerly known as Adaboy.......

I use this brace-funny no one asked the demensions!
As I posted it's part of a plan to get the center of the top stiff.
Making the center stiff and the edges flexible is the sound I like .
Plus it helps with the loudness of the guitar & responce!
The guitars have better sustain also .
I do not make Dreads-just small steels .

Mike

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Mike Collins

When I say "one dimensional" I mean........very few overtones, quick decay on bass, but kinda naisley, with too much sustain on the treble.

I'm not saying these braces cause this. I'm saying a top that's too stiff across the grain causes this, or can cause this.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/