Official Luthiers Forum!

I'll start a new thread on a side topic from another thread.

I read an old thread where David Berkowitz was describing Huss & Dalton construction techniques used on their TDR (Traditional Dreadnaught) model. He described they glued a radiused top (braces glued in a radius dish) to a flat rim. It's unclear to me if "flat rim" means the rim is radiused in a dish and the lining is then glued in and left flat.......or if he means the rim above the soundhole is radiused and the rim below the soundhole isn't radiused but left flat and the lining also glued in flat. Can anyone shed light on this?

Apparently, springing the radiused top onto the flat rim resulted in a different tone. Here is how David compared the tone of H&D's TDR to their modern dreadnaught (which uses a radiused top glued to radiused rim):

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Formerly known as Adaboy.......

Try this one.

http://www.mimf.com/library/domed_tops.htm

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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.

Darryl buddy I built a dread about 4 years ago with the Huss & Dalton building methods where the top is radiused but the rim is not radiused for the top. At that time I also had a very nice H&D CM and I was a fan of H&D in general, still am.

Although David's description of the tone of H&D traditional models is excellent above I would add that the dread that I built did have a more traditional dread tone than some of the other dreads that I built with radiused sides. To be more specific what I believe that I heard was less mid-range, more bottom, and that not-all-that-uncommon slight tubby sound that dreads can have.

The guy who has this guitar now and for the past several years says he loves it and it lives next to his Steinway. He mostly plays Bob Dylan stuff.

Thanks, Hesh, that was the descriptor I was looking for in the other thread. Hesh's explanation echoes the commonly held opinion of those who have spent time with both. (As I stated in the other thread, I have played a TDM/TDR, but not a DM/DR for comparison.) The consensus is that the fully radiused rims - all else being equal - tends to lend itself to more perceived midrange. Thus, more "modern" than "traditional" - which may or may not be a good thing, depending on what you're after. In fact, I just popped over to the H&D website and - though they don't give any construction specifics - they describe the Traditional series instruments as "flattop construction" (males me wonder if they still radius the bracing?) and describe the DM and D-RH as having a "boost to the midrange". So there you go.

I wonder, though, if what is describes as "tubby" is actually just the loss of midrange. The TD-R I played was FAR from what I'd describe as tubby! I was loud, punchy, and clear as all get out!

http://www.hussanddalton.com/index.html

BTW, since I guess I helped kick off the discussion on the other topic, here was my response to Darryl's question about the differences and construction techniques:

"Darryl, I don't have a large base to go off of for comparison. My first was radiused all the way, and the last few have all used this technique after reading about it some years ago on the MIMF. I started trying this method after reading a general consensus that it generally gave a more "traditional" tone (however you want to read that.... ) over fully radiused rim. I do know that Huss and Dalton uses this method on their "traditional" series instruments, while they use a radiused rim set on their more contemporary line. That was the first place I heard of it. A good A/B would be to play a H&D DM vs. a TDM and see for yourself. I haven't played a regular DM for comparison, but I do know that the one TDM I played was one hoss of a guitar! Those who have played both tend to describe the DM as more "modern" in tone. Again......

I can tell you that I am continually getting closer to "that" tone in my head - you know, the one we're all looking for. (Well, OK, so you're not looking for the tone in MY head, but you know what I mean ) But to use my first (and only) radiused build for comparison wouldn't be fair. The difference between my #1 dread and #2 OM was striking to say the least (the OM just killed the dread!), but I certainly can't say that it was because of any one thing. Since that point, I've been sticking to this basic methodology for my subsequent builds and making smaller tweaks until I build a broader knowledge base. At some point in the future - when I've reached some amount of consistency and repeatability and know what to expect from this bracing - I may branch into other ideas and learn from those as well. Just part of the never ending tone quest, my friend!

As far as the construction, you've pretty well got it. I brace my tops (so far) on 25' and sand my rims flat. When I'm done, I shim the sanding board at the tail somewhat like Hesh shows and take the upper bout down to around the waist area. My upper bout bracing is all flat, BTW. I use a flat UTB and flat A-frame bracing inlet into the neck block. The lower bout is radiused and everything down there stops short of the linings. So you could say the top is "sprung", I suppose, but it's a very small amount.

I guess it's another one of those things that you don't know WHY it works, it just does. At least to the ever-subjective satisfaction of many. You would expect it to somewhat stiffen the perimeter of the soundboard, if anything, when many are trying to loosen that area. Of course, it could be said that by stopping all my braces short of the linings the perimeter is already looser.

Never measured the final dome of the top after bracing, but I can't see where it would be changed much. The soundboard bracing should maintain the shape pretty well and only the perimeter is "stressed", so to speak."

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Wes McMillian
Santo, TX
http://www.wesmcmillian.com

Hesh, is that an ADI top on that Dreadnaught? Very nice looking guitar!

I'm still trying to get a clear definition of what "flat rim" means so let me ask a question about the lower bout of the Huss & Dalton construction technique (ignore the upper bout as I understand what is happening there). Is the lower bout rim radiused with a dish then the lining glued in and the top of the lining left 90 deg to the sides (not radiused)? Or is the rim of the lower bout sanded flat and the lining glued in and left flat?

Thanks again!

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Formerly known as Adaboy.......

Darryl - yes it's a very nice strippy Adi top.

You may be over thinking this in as much as my definition of a flat rim is a rim that has not had a radius sanded into it. Lots of folks are still building true flat tops and although they may or may not impart a radius to the top with a number of different methods the rims are flat.

As Wes said H&D is not all that clear on how they are doing the TRDs but my guess when I built my flat rimmed dread was that they simply left the rim including the kerfed linings flat meaning no radius at all.

So just think of it as a rim with kerfed linings installed and no radius at all.

I can't speak to Huss and Dalton's methods but I do something similar with my guitars. I do not taper the rims at all before bending and once bent I level them to each other so they are the same width all over. I put a taper in to the top and the back (much more for the back) that is a straight line taper usually from just in front of the waist for the top and at or maybe a bit behind for the back. Once they are in I lightly round the sharp point where the taper meets the flat part of the rims. Next I glue my linings in and level them to the top of the sides (at 90 degrees). My top and back are glued up with the braces with radius forms. Sometimes each brace has a slightly different radius, the back braces always do. The x braces lately have been 17 and the third back brace has been 10. Next I clamp the top and back to the rims and using my radius guages see what actual radius they form when forced in place along their lengths. I mark this on the sides of the guitar. With PSA snadpaper on my radius guages (these are 22 long and 1 1/4 wide) I sand the surface of the linings only to this shape around the rims. Then I glue on the top and back. You do have to force it, especially at the waist, but I get very clean glue joints.

I like the idea of the tops being stressed into place and i love the heavy dome I get in front of the bridge. Being able to control locally the radius means I can easily flatten behind the bridge too and a lightly built guitar will pull itself slightly into what looks like a more even doming. The part I like best is that I can leave the upper bout of the back completely flat, like people do with their tops. I feel that the collapsing dome of the back is a big factor in neck resets and if that area is flat it is much more able to resist the heel pulling out.

It took me a little while to get all of the different radius' figured out so that the finished guitar looks "normal" and the transitions are smooth but I am very happy with my system. I don't notice any tubbiness but then again I am not building Dreads. At least lately.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

My understanding was that on the TDR, the rimset, linings and all, were surfaced flat and the domed top glued down to it.

Burton, that sounds like an interesting and intriguing method. Aren't you afraid that extreme dryness may collapse the upper bout of the back a bit? You seem to have everything figured out, so probably not.

The side profiles on older Martins and Gibsons I've seen look like the top was glued on a flat rim, as the waist follows the taper progression, rather than become wider, as it does when the rim is shaped in a radius dish. The top also looks fairly "flat" from head to tail. Gluing a radiused top shouldn't be a problem with 60', or even 30' radius as light sanding will even things out pretty quickly.

I am intrigued by why and how this should change the tone in this or that way, though.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I've been to their shop (a few years back) , and that's the way it looked to me.

For me/my builds, the dome, and rims have a resonable impact on the........"personality" of a guitar. Unless I'm trying to do something different for a client I normally use domed rims on dreads and flat rims on smaller bodied guitars. To my ears the domed rim helps give the dread some sparkle, and the flat rims helps with bass on smaller guitars. I taper my flat rims from the upper transverse brace forward to keep the fingerboard level, and the same thickness from the body join to the soundhole.

I'm not sure how H&D handles the neck/body transition. FWIW, I've never owned a H&D guitar but I am a fan.

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

Laurent,

That is a worry but so far the guitars I have monitored closely have had no problems. I am using the "foot" which extends the neck block to the first (flat) brace and I keep my 2 upper braces at mostly full height across. The second (waist) brace has a very slight radius to it and I am capping my back graft with parallel grain spruce, which runs under the braces to the 4th brace. I am also building with a little lower RH than some, I try to stay just under 40. Certainly all of those things may not stop a back from concaving a little but so far they have stayed pretty true.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

My first 4 guitars were built with radiused top braces and dead flat rims. I followed the Kinkead book and I thought they turned out very well, at least until I found out about luthier forums on the net! Then I knew that these first 4 were overbraced, that was easily remedied (I can say that now because the forearrm pains are long gone!). But there was nothing I could, or should I say, was going to do about the unradiused rims. It was a good learning experience on the effect of shaving the braces,, anyway they all really sound great now. Compared to the guitars I build now, with a radiused rim and top, some with a flat UTB and some radiused, they have a less complex tone (at least to my ear).

One other thing about a guitar with flat rims and radiused top,, if you look at the souind hole closest to the bridge, it looks as if the top is caving in (I'm talking such a small amount that only a builder or repairpersons eye would notice). This is due to the fact that the rim would be higher at the waist if radiused (as Laurent was saying). And since the rims are flat, the top is pulled down in this area of the soundhole. This was confirmed to me on another thread when Wayne Henderson"s guitars were brought up. I can't remember for sure who it was that had the opportunity to meet Wayne and play one of his guitars,, but they talked to Wayne and found that he builds with flat rims and radiused tops. They also commented on here that it appeared as if the guitar was caving in below the soundhole ever so slightly. Which is the way it would look if built in that manner.


Makes me wonder if I should go back to my original method!?


Chuck

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Burton,

That is a neat method you are using. Did you make a special caul to glue the top to the rim or are you using clamps around the perimeter or what? I have the back glued to my rim and I have a 1 1/2 deg angle sanded above the soundhole. It's an OM body and I'm trying to decide if I want to leave the rest of the rim flat or radius it. Since it is an OM body and I want to use it for flatpicking, I'm leaning toward leaving it flat. My top has a 28ft radius. If I do, I will follow your example and sand the rim where the 2 angles meet so its not an abrupt change which would kink the soundboard a little. I'll also have to figure out how I will clamp the top while gluing. Might make a caul 1 1/2" wide that goes around the perimeter use the go-bar deck.

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Formerly known as Adaboy.......

Chuck, that may be legitimate with a dead flat box and flat bracing once it strung up and torque placed on the bridge, but radiused bracing should maintain some amount of dome in that region. I haven't played Henderson's guitars so I certainly don't know what is going on there. But, even if that is the case, it should be remedied by planing/sanding a flat taper in the upper bout as many folks do. The rim (at least a I do it) is flat, but in two planes - split around the waist. The main part of the sound generating lower bout is, indeed, radiused while "stressed" to a flat rim. The upper bout is braced flat to another flat plane tapered (very slightly) to match the neck set.

Of course, there are those who also say a slight amount of dip in front of the bridge is a sign of a good guitar, too. Kinda like a bit of belly behind the bridge. To quote Norman Blake: "Never trust a guitar that doesn't have a belly."

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Wes McMillian
Santo, TX
http://www.wesmcmillian.com

Wes, just to clarify, the top still maintains its dome, it is just a liitle lower at the bottom of the soundhole due do the dead flat rims. The rims are in one plane, unlike the way you describe your method. Remember, if the rims were radiused. they woud be higher (wider) at the waist (adjacent to the bottom of the soundhole). Then the dome at the bottom of the soundhole would be that much higher. Again, I am not sure if it would be noticeable to anyone other than a builder or repairperson.

Chuck

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"Flat rim" simply is one in which its perimeter surface lies in a single plane.
As discussed above Martin built in this mode insofar as the top is concerned. Martin tops (the traditional ones anyway) have a slight radius and are fitted to the flat rim. When I built in this mode however I would slightly relieve the outer portion of the linings and blocks to ensure complete contact at the inner margin of the kerfing.
A "domed" top (that which is fitted to radiused sides) is stiffer for a given thickness and bracing structure so the brighter sound is consistant.
In classical guitar construction the elimination of top mass is important due to the limited amount of energy available from the strings. Thus "doming" the top is a way to decrease mass by thinnng and maintaining stiffness.

Exactly. the top rim forms a single plane from butt to neck the top is braced with radial shaped braces but the glues down to flat lining. I have done this for years on all my models.

it is no differnt than if you radiused sanded the rim. you shape and flise the heels to properly pitch the neck.

Darryl,

I don't have a caul, I just load up on clamps. So far it is good.

Wes,

I don't mind a belly at all but the dip makes me very nervous.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

Me too. IME a dip in front of the bridge it is one of the first death signs of a top collapsing.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

The pitch of the neck isn't what I'm talking about. If the rim is truly flat there's going to be terrible fall off of the fingerboard where it meets the body. On flat rim builds I taper my sides for the correct geometry. I suppose my flat rims aren't completely flat.

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

Sounds like Woody does his much like mine. So, no, my sides aren't completely flat - as in one plane. But the linings are all at a right angle to the sides creating what some are calling a "stressed" joint.

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Wes McMillian
Santo, TX
http://www.wesmcmillian.com