Forward Shifted Bracing, Why Did it Take So Long?

[steveyam]

I realise it's a complicated subject and that a short answer is perhaps difficult to give, but could a luthier or knowledgeable person explain to me the difference? Obviously, I can see that the bracing is moved back towards the tail of the guitar to strengthen the lower bout when used with heavier strings. But is it as simple as that? Does the bracing fundamentally change in other ways, or basically is it just a shift backwards (or forwards!). Thanks. Links to bracing descriptions would also be good!

[fullsmile]

Maybe but a lot of others like the D-45 still have the older bracing so not all the high end have forward shifted. Also it is not only martin, taylor is doing the same thing on high priced guitars.

Originally Posted by SuperB23

Forward Shifted is older than the more modern tapered that came in the mid to late 40's

A company like Martin can charge more for what most would consider to be a "better" sounding guitar. I would think 95 out of 100 guitars players would think a HD-28V sounds better than a new standard D-28.

Look at the D-28 Lineup over the past few years:

D-28 Standard Tapered X Bracing $2k
HD-28 Scalloped X Bracing $2.5k
HD-28V Scalloped forward shifted X bracing $3.1k
D-28 Marquis More heavily scalloped forward shifted X bracing $4.1k
D-28 Authentic. More heavily scalloped forward shifted X bracing $30k

Each time the bracing gets closer to a prewar D-28 and each time the price goes up. The top three are all the same woods sitka and EIR so its not a wood price thing. Obviously the last one has the super premium for Brazilian and collectability.

[TinyMontgomery]

Originally Posted by steveyam

I realise it's a complicated subject and that a short answer is perhaps difficult to give, but could a luthier or knowledgeable person explain to me the difference? Obviously, I can see that the bracing is moved back towards the tail of the guitar to strengthen the lower bout when used with heavier strings. But is it as simple as that? Does the bracing fundamentally change in other ways, or basically is it just a shift backwards (or forwards!). Thanks. Links to bracing descriptions would also be good!

http://theunofficialmartinguitarforu...RACING-LIBRARY

[pksghost]

From Martin's website:

http://www.martinguitar.com/guitars/...s/bracing.html

Its all about vibrating the top freely....

Notice that Martin uses different patterns for dovetail and M&T guitars.
PK

[zabdart]

Every operation you do in building the box of an acoustic guitar is a trade-off between structural strength and tone. Both Martin and Gibson used "forward-shifted" X-braces on their flat-tops in the 30's because this results in a more "open" or "airier" tone. After World War II, Martin moved their X-braces back 1/2 inch from the soundhole to compensate for the use of medium gauge strings. Gibson did not -- compelling them to find other, less acceptable ways of compensating for the use of heavier gauge strings.
The Larson brothers, by contrast, always set their X-braces about 2 inches behind the soundhole, resulting in a very dry, clear tone.

[valleyguy]

Originally Posted by pappy27

So it costs $500 to get the braces scalloped; and $600 more to move them up an inch or so?

The move from D to HD involves the herringbone trim , so that seems justified. But $600 more for the V seems a little much. I've not seen that the V has much more than the HD, maybe better woods?

[jimmy bookout]

A little Martin history for you:

The original style 28 dreadnaught was simply called the D-28, it had herringbone trim. This herringbone trim was sourced from Germany and became unavailable post WWII so the binding changed to the simpler black/white. The reality was that a herringbone D-28 from 1946 is structurally identical to a non herringbone 1947 D-28. These original D-28's had "forward shifted" braces and small maple bridge plates (and, of course, Brazillian Rosewood back and sides). As we went into the folk/country boom and folks began using heavier gauge strings for volume, Martin reacted by moving the bracing back (away from the soundhole) and switched to a larger, rosewood bridge plate. Also during this period, Martin switched to Indian Rosewood around 1969 because Brazil stopped selling Martin wood in log form, Brazil wanted to saw it in Brazil and Martin found that unacceptable. Martin introduced the HD-28 in the 1980's as an attempt to structurally replicate the earlier D-28's, i.e. small maple bridge plate and forward shifted braces (but Indian Rosewood back/sides).

Jimmy

[Tim McKnight]

[QUOTE=steveyam;2744768but could a luthier or knowledgeable person explain to me the difference? [/QUOTE]

Moving the X intersection (the stiffest area of the top) towards the sound hole will allow the bridge more freedom to rotate because the bridge is mounted above a weaker area of the top's brace structure. Pretty simple physics.

[1folksinger]

One of the finest "vintage" guitars I've ever played, doesn't have 'forward-shifted' braces, nor are they 'scalloped.' It's my 1964 D-18, complete with a Sitka top, and 1&11/16'th neck. Granted, about two years ago, I had the neck re-set, and the bridge & fingerboard replaced, but the rest of the box is an original 1964 Martin D-18 all the way. When it comes to flatpickin' or rhythm strummin'... it's one of the very best. Do I think about the braces when I play it? No. Do I think about the bracing pattern when I hear that punchy, dry tone? No. Does it make wonderfully sweet music? Yes.
As for how Martin braced or shaped the braces of their tops way back during the so called "Golden Era," the 1939 00028 Martin I have, does have tapered braces, but does not appear to have the "forward" brace pattern of this discussion. The braces that are nearest the sound hole, are actually closer to the bridge than the 2001 OM45 Martin "Golden Era" I also own. Yes, one is a '39 00028, and one is patterned after a 1933 "OM45." The 00028 is not only rich in the bass, but it sparkles in the high end as well.
I'm not sure what really started the changes in the bracing patterns many years ago, all I know is, both models are very fine instruments that sing, stay in tune and bring joy to everyone that hears them. Nobody has ever asked me how the tops are braced. Not yet anyway!
Keepin' the acoustic faith!
1folksinger

[pappy27]

Originally Posted by pksghost

Yes, supply & demand and a higher margin built in for potential lifetime warranty issues. The scalloping is done by hand, so you do hafta pay a skilled person adequately to get it right.

PK

I understand the supply and demand issue and that will always rule. Whatever the buyer is willing to pay is the correct price.

However, $500 upcharge for someone to carve braces is what the buyer is paying. If a worker does only one top an hour that's a pretty good return on investment.

On shifting the bracing for a $600 upcharge, supposedly to cover more future warranty work cost, are there any statistics on HD-28V vs. HD-28 and D-28's?

Here's a good overview and pics of both types of bracing
http://www.oldcloset.com/braces.htm

[Hotcole]

Originally Posted by murrmac123

The so-called "forward shifted bracing" was actually the original way that Martins were made , and the bracing was shifted rearwards to cope with the advent of heavier gauge strings.

Bingo! Thank you and good night.

[steveyam]

Originally Posted by Tim McKnight

Moving the X intersection (the stiffest area of the top) towards the sound hole will allow the bridge more freedom to rotate because the bridge is mounted above a weaker area of the top's brace structure. Pretty simple physics.

Surely the idea of the exercise is not to facilitate the bridge to rotate which is clearly a negative trait, but to enable the whole bridge area to vibrate more? The way you put it, it suggests that bridge rotation is the reason for the move, not an unfortunate side effect. The physics may be simple, but the answer is far from clear. Simple English.

[sfden1]

Originally Posted by fullsmile

I know that in todays guitar world it is all about the forward shifted bracing. If this bracing is so great and superior to traditional bracing why did it take so long to develop?

It's been around since the 1930's, at least, maybe longer. You might say that forward shifted scalloped bracing is "traditional"

D.

[fulfillingsoul]

Originally Posted by sfden1

It's been around since the 1930's, at least, maybe longer. You might say that forward shifted scalloped bracing is "traditional"

D.

Hmm... is this "forward shifted scalloped bracing" also known as "Pre-war scalloped bracing"?

[Tim McKnight]

Originally Posted by steveyam

Surely the idea of the exercise is not to facilitate the bridge to rotate which is clearly a negative trait, but to enable the whole bridge area to vibrate more? The way you put it, it suggests that bridge rotation is the reason for the move, not an unfortunate side effect. The physics may be simple, but the answer is far from clear. Simple English.

While shifting the bracing forward the bridge remains in the same place. Therefore the bridge is mounted to a weaker area of the top's braced structure than it was before the X intersection was shifted towards the sound hole. The bridge will move a greater distance fore and aft, in the long dipole mode (along the length of the grain lines), than it could before the shift, given the same amount of energy imparted by the strings vibration. The result {can} be more volume and a change of timbre. Combine this move with scalloped bracing and the bridge is mounted to an even weaker area of the top which equates to greater deflection.

There will always be a trade off in structural integrity and a fine line of engineering the right balance between maximum tone, response, top distortion and implosion (the top folding into the sound hole).