Members knockwood Posted August 23, 2005 Members Share Posted August 23, 2005 Would any of you smarties be able to explain parabolic bracing in a way a dope like myself might be able to understand? Is there a significant - any - difference between parabolic and your average scalloped bracing? Or is parabolic just a rose by another name? My eyes cross just reading the definition of parabola in Webster's... Link to comment Share on other sites More sharing options...
Members JasmineTea Posted August 23, 2005 Members Share Posted August 23, 2005 Although I'm a dummy, here's what I think it is after doing a search: I've seen braces that were carved in such a way as to resemble a knife edge. The carving starts at one end of the brace, on both SIDES of the brace, and gradualy cuts deeper, leaving the center uncarved. convex or concave, I imagine it could be done both ways. OR, I could be completely wrong, and it's simply refering to carving like the long braces in this pic: Link to comment Share on other sites More sharing options...
Members bjorn-fjord Posted August 23, 2005 Members Share Posted August 23, 2005 Parabolic bracing is simply bracing with a dome or arch shaped cross-section. It's gimicky, in my opinion. But it sounds hi-tech and cutting edge. Parabolic Bracing. Ooooh. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted August 23, 2005 Members Share Posted August 23, 2005 Basically it's like a suspension bridge, If you hold a string with two hands and let it sag in the center...you will get a parabolic shape instead of a oval or circle. The radius of curvature will flatten in the periphery. I think in structural engineering it's considered most efficient in the strength to weight ratio. I'm pretty sure most scalloped bracing follows a parabolic profile instead of a fixed radius anyway. Link to comment Share on other sites More sharing options...
Members knockwood Posted August 25, 2005 Author Members Share Posted August 25, 2005 Originally posted by bjorn-fjord Parabolic bracing is simply bracing with a dome or arch shaped cross-section. It's gimicky, in my opinion. But it sounds hi-tech and cutting edge. Parabolic Bracing. Ooooh. LOL. I asked largely because your old boss, Jean Larrivee, uses pretty much strictly "parabolic" bracing on Larrivee guitars. The part that's confusing to me without any kind of photo or illustration of the braces themselves is that the descriptions I keep hearing - the suspension bridge comparison, for example - all call to mind images of garden variety scalloped braces... I'm pretty sure I'm the kind of dumb {censored} who has to actually see the guts of a Larrivee top to comprehend what's being described. Anyone have any pics of parabolic bracing? Link to comment Share on other sites More sharing options...
Members Luv2Play Posted August 25, 2005 Members Share Posted August 25, 2005 Pretty funny to read "gimmicky" as Parabolic bracing has been around for a long time. It is different than most builders use but is in fact a very legitimate way to brace a guitar. I just strung up a 13 fret to the body 25.4" scale guitar that I built with Parabolic Bracing throughout and it sounds amazing, as good or better than my tester guitar, a $5000.00 Goodall that sings like no tomorrow. So yes there is more than one way to skin a cat, and Parabolic is for real. By the way, this Parabolic braced guitar is for sale if anyone is interested....Black Walnut B/S with An Amazing Curly Spruce top. If your interested email me @ gwaltney@mindspring.com for pictures and pricing. Thanks,Greg Link to comment Share on other sites More sharing options...
Members JasmineTea Posted August 25, 2005 Members Share Posted August 25, 2005 Would someone please post a pic? Link to comment Share on other sites More sharing options...
Members Luv2Play Posted August 25, 2005 Members Share Posted August 25, 2005 Guys, Check out Scott Van Linge's website for some info on Parabolic Bracing. www.vanlingeguitars.com Greg Link to comment Share on other sites More sharing options...
Members knockwood Posted August 25, 2005 Author Members Share Posted August 25, 2005 Originally posted by Luv2Play Guys, Check out Scott Van Linge's website for some info on Parabolic Bracing. www.vanlingeguitars.com Greg That one's going in faves. Thanks, man! Link to comment Share on other sites More sharing options...
Members JasmineTea Posted August 25, 2005 Members Share Posted August 25, 2005 I saw an artical in an old GP magazine where they did a study of vibrations with violin backs. They put some kind of tiny, sand-like beads on the violin back, placed it over a speaker playing certain notes, and took pictures of where the beads settled. Link to comment Share on other sites More sharing options...
Members bjorn-fjord Posted August 25, 2005 Members Share Posted August 25, 2005 Originally posted by Luv2Play Pretty funny to read "gimmicky" as Parabolic bracing has been around for a long time. It is different than most builders use but is in fact a very legitimate way to brace a guitar. I just strung up a 13 fret to the body 25.4" scale guitar that I built with Parabolic Bracing throughout and it sounds amazing, as good or better than my tester guitar, a $5000.00 Goodall that sings like no tomorrow. So yes there is more than one way to skin a cat, and Parabolic is for real. By the way, this Parabolic braced guitar is for sale if anyone is interested....Black Walnut B/S with An Amazing Curly Spruce top. If your interested email me @ gwaltney@mindspring.com for pictures and pricing.Thanks,Greg I meant that it's gimicky to refer to a very common practice in luthiery as though it is something new. Every guitar I have ever built (and that includes bracing many, many Larrivees) has "rounded" bracing. To attribute such a common practice with a ten dollar moniker sounds like a marketing gimmick to me. Link to comment Share on other sites More sharing options...
Members Luv2Play Posted August 26, 2005 Members Share Posted August 26, 2005 O.K.....Parabolic vs. Rounded.....I guess Parabolic can be deemed a fancy way of saying rounded, or gimmicky MAYBE. But the two terms can mean very different shapes if we are not careful. Yes Parabolic has rounded shoulders, but is very specific where it is rounded. Anyway, I get your point and I'm with you relative to hyperbole. Greg Link to comment Share on other sites More sharing options...
Members bjorn-fjord Posted August 26, 2005 Members Share Posted August 26, 2005 Originally posted by Luv2Play O.K.....Parabolic vs. Rounded.....I guess Parabolic can be deemed a fancy way of saying rounded, or gimmicky MAYBE. But the two terms can mean very different shapes if we are not careful. Yes Parabolic has rounded shoulders, but is very specific where it is rounded. Anyway, I get your point and I'm with you relative to hyperbole. Greg I should provide a caveat to my past statements on this topic. Since working with Larrivee about 12 years ago I have built on my own in a small town with no connections to any other builders. I have been operating in a relative vacuum. I don't even read Acoustic Guitar magazine. So, in this context, it is entirely possible that parabolic bracing has come to the forefront of the guitar community's consciousness and I have been blissfully unaware. I guess it just seemed natural to me that in a system where the goal is to maximize strength and to minimize mass that a parabolic brace shape was the obvious choice. I thought almost everybody made braces that way and those that didn't just considered it a short-cut worth taking to decrease production costs. I guess I am an accidental innovator! Link to comment Share on other sites More sharing options...
Members black friday Posted August 26, 2005 Members Share Posted August 26, 2005 actually guys, a piece of string, cable etc. does hang in a parabolic arc. It may be a shallower or deeper one than you are used to seeing, but it's definitely parabolic. But surely in this conext parabolix is just applied to mean shaped braces? Do they actually carve the cross section to an exact or approximate profile of a parabola? Link to comment Share on other sites More sharing options...
Members Luv2Play Posted August 26, 2005 Members Share Posted August 26, 2005 Good point...they arn't truly parabolic, their quasi-parabolic! so if there not truly parabolic then what are they...rounded? The damn things are just arched like a dolphins back, minus the dorsal fin. Hey we could call these braces ....flipper-like. Link to comment Share on other sites More sharing options...
Members Scott van Linge Posted August 26, 2005 Members Share Posted August 26, 2005 Greetings: I may be partly responsible for introducing ''parabolic'' to the consciousness of the guitar world when I founded Parabolic Brace Works in 1996, a business in which I reshape existing braces to maximize a guitar's potential. I shape braces in length and cross section in approximately parabolic curves, although I do not follow a strict formula. This allows the energy from the strings to flow through the braces to the soundboard in a streamlined manner, while reducing unnecessary mass (i.e., not needed to balance string tension). Corners, ridges, peaks (as left by scalloped bracing) all absorb energy before it can make sound. Scalloped braces are not parabolic, and I feel are a cheap fix to loosen up the top, which can cause failure, although they do allow for better sound than even-height braces used by Martin in the 50's-70's. Larrivee shapes their top braces parabolically lengthwise, but leaves them square cut in cross section, which leaves corners the entire length. If you ever get a chance to look into a vintage Martin, you will see parabolically shaped back braces, both lengthwise and in cross section. I have seen variations on top braces that were not completely scalloped, and the short side braces were parabolic back then. Another term used for lengthwise shaping is ''tapered'', which also describes a gradual lowering in height as the brace ends. This allows the strength and mass to be reduced as the braces move away from the string tension area under the bridge, much as it takes less force to balance a teetertotter further out from the fulcrum. I have gone into detailed discussion and posted pictures on my web site, vanlingeguitars.com. parabolicbraceworks.com will get you there, too. Scott Link to comment Share on other sites More sharing options...
Members JasmineTea Posted August 26, 2005 Members Share Posted August 26, 2005 Scott, I imagine you would not carve a brace with a perfect taper, but would instead determine what note(s) are dead, find the corresponding section of the brace, and carve more at that point? Do you ever add mass to quiet a loud note? Link to comment Share on other sites More sharing options...
Members Scott van Linge Posted August 26, 2005 Members Share Posted August 26, 2005 Jas T Actually, I try to shape the braces as perfectly as possible, and quiet notes invariably end up pointing to a place that is not perfectly shaped. I seldom, but sometimes add a brace to quiet down notes, and have added carefully shaped pieces to fill in scalloped areas that are too much, but usually am able to get perfect results working with what's there. Scott Link to comment Share on other sites More sharing options...
Members guitarcapo Posted August 27, 2005 Members Share Posted August 27, 2005 I build guitars too, Scott. I've found in my experience that the shaping and placement of the bracing isn't as important as some other factors for tone. My number one factor that changes tone a LOT is the thickness of the soundboard at the lower bout and whether the braces are thinned to a taper there or left thick. Scalloping does add some bass and thickness to the notes but loses bell-like, crystaline trebels on the first string. Most of my guitars have evolved over the years to a "jumbo" shape like a J-200 or J-185. Non scalloped, tapered X bracing that thins out to nothing just as it hits the kerfing. Maybe a little thicker soundboard on the trebel side. Box size, depth, bridge construction, and scale length seem to matter a lot in the tone. Back and side woods have proved a very poor determinant as to the final tone. Link to comment Share on other sites More sharing options...
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