The Martin D-28 vs. HD-28. What’s the diff?
What is the difference between the Martin D-28 and the upgraded version of it, the HD-28? The answer is found in their price, their looks, and their tone. And the reasons behind all three can be summed in the phrase “scalloped bracing.” The HD-28 has it; the D-28 doesn’t. But what exactly is scalloped bracing and why does it matter? On Monday, February 8, Maury took part in an online symposium dedicated to comparing these most-loved Martin models and how scalloped bracing played a part in their evolution. The panel included Aaron Short who was hosting it on his YouTube channel, Aaron Short Music, and featured our pal Spoon Phillips. It proved to be both educational and entertaining for all who’ve seen it live and in its pre-recorded version. And you can enjoy the symposium yourself, by watching it HERE .
A Stressful Situation
A world-class acoustic guitar is made of very thin plates of solid wood that miraculously create beautiful tones when physical energy is passing through them. When tuned to concert pitch, the six strings of a guitar bring between 150 and 200 pounds of tension to bear upon the soundboard of an acoustic guitar, aka the guitar’s top. Without the wooden struts glued to the underside of the soundboard, it would soon warp and then be ripped to pieces by the stress from those taught steel strings.
The trick is allowing the top to be strong enough and yet remain flexible enough to convert that stressful pressure into as much resonant tone as possible. And since these struts, known as bracing, help transfer the physical energy from the vibrating strings across the soundboard to the sides, and back, so that the entire body vibrates with tone-producing energy, their exact size and placement on the top is very important. Scalloped bracing refers to a technique where the wooden struts are shaped to be more flexible in specific areas, while being stiffer in other areas. This is done by scooping out wood in certain portions of a strut, while leaving peaks along the way. These struts typically include larger braces, like the main X-brace, smaller side braces, and “tone bars” which play an important role of manipulating the resonant frequencies that become the audible voice of the instrument.
As you can see in the example of scalloped bracing, the braces and tone bars below the sound hole have been shaped to have graceful swaths of wood scooped out of them. In some places, the peaks of the braces are hand-carved into delicate points, giving the tone bars and X-brace a silhouette that reminds some people of a suspension bridge.
Scalloping makes each brace or tone bar lighter and most flexible at the bottom of the curve. The peaks are placed in precise locations, offering localized stiffness that allows the builder to determine which resonant frequencies they wish to squelch and which ones they wish to promote. This now famous X-brace pattern was invented by C. F. Martin Sr. in the 1840s and was perfected by his decedents, and is now copied by guitarmarkers around the globe. It proved to be an ingenious way to harness the potential energy of steel guitar strings and convert all that powerful stress into powerful, beautiful tone.
To Scallop or Not to Scallop: A Tone of Contention
C. F. Martin & Company converted their guitars from gut strings to steel strings starting in the 1920s. In the 1930s they invented the modern 14-fret acoustic guitars, which have longer necks and smaller tops, increasing the string tension per square inch of soundboard. They stopped using scalloped bracing in the late 1940s and did not return to it until the mid-1970s, and only on a few select models like the M-36 and HD-28. By the turn of the century almost all of their professional level guitars had scalloped bracing. This is because more people prefer the tone over guitars with non-scalloped bracing. But not everyone. Scalloping the braces allows the spruce top to vibrate more easily than on a guitar with non-scalloped braces, yet in a precisely controlled manner. This results in a guitar that is more responsive to lighter playing and that has a greater resonant reverberation during harder playing. And when it comes to large guitars like Martin’s Dreadnought size, there is a natural EQ adjustment with a “mid-range scoop” that promotes the bass and treble to the forefront. And that is the sort of dynamics and tone you get from an HD-28.
A spruce soundboard supported by non-scalloped braces responds differently. So the D-28 has a voice that has prominent fundamental notes, each with their own strong, full sound from each individual string. The resonating tone from the rosewood sound chamber and the sympathetic harmonics from the main notes are present, but not as projecting and dominant as the fundamental notes. The natural EQ of the D-28 has a punchy mid-range and a more balanced tone overall, which is focused on the main notes.
The 2017 Martin D-28
Therefore, the HD-28’s voice is more complex, with noticeably greater body resonance and overtones and undertone that harmonize with the fundamental notes to a greater degree. It has a 3D quality to the overall sound, which creates a sense of openness and depth, filled with multiple textures and sonic layering.
This does not mean the D-28 is devoid of such musicality. But it has its own recipe with its own signature sound. The voice is punchy and projective and downright explosive when under vigorous strumming or when soloing with a thick flatpick. The notes remain distinct and leap out with great clarity, while sacrificing some of the complexity and 3D expansiveness of the HD-28 with its scalloped braces. But there is less sympathetic reverberation from the non-scalloped voice of a D-28. And some people prefer that, because of how the individual notes to stand out into a room or in a “mix” when playing or recording with other musical instruments.
Both guitars have their devoted fans, with good reasons. They are, after all, two versions of what is basically the same thing, but drawing inspiration from separate periods in the long and storied history of the most famous acoustic guitar in the world.
Parallel Legacies, Reimagined and Refreshed
Today’s HD-28 is inspired by the D-28 made before the Second World War, which had herringbone top trim and the Diamonds & Squares pattern for its fret position markers, and was made with scalloped braces. The D-28 is closely related to D-28s made after the war, with non-scalloped braces, and is in fact their direct decedent. It is truly a legendary musical instrument, imitated by countless guitarmakers, but never recreated. And that is one reason it remained virtually unchanged in its design for sixty years, beginning in 1947.
That was the year the Martin settled on their redesign of the D-28, after a couple of years of tinkering around with what they wanted it to look like and what they wanted it to sound like. And that design included non-scalloped bracing to create a clear voice with powerful tone, for when someone was playing at a barn dance or on the radio or in the recording studio.
Gone were the herringbone trim and diamond fret markers that originated in the 1800s. In their place were the limpet mother-of-pearl domino dot markers and the black and white ply top trim inspired by the Art Deco school of design popular at the time. The results were acoustic guitar appointments that became almost generic in look, because they were copied by just about everyone out there who was making inferior guitars, which they hoped would resemble a D-28. As the old saying went, “More people owned or wanted to own a Martin D-28 than any other guitar.”
When the model was finally “reimagined” in 2017, the designers chose to add Aging Toner to its solid spruce top and Antique White binding to make it look even more like a D-28 from the 1950s. And they kept in place its non-scalloped bracing. After all, that was the sound beloved by millions who heard it on songs of Hank Williams Sr., Elvis Presley, Tom Paxton, and iconic Beatles records like the White Album, Abbey Road, and Let It Be, along with records by Led Zeppelin, Joni Mitchell, John Prine, Michael Hedges; the list goes on and on.
The Reimagined Martin HD-28
But across those same decades, more and more people were becoming familiar with the D-28s made in the 1930s and early 1940s, which had a different kind of sound. It was one that reverberated with woody undertone that made the guitar sound like it had a large open cellar and grander harmonic complexity. And Martin began experimenting with how to offer guitars that came closer to that pre-war tone.
The first attempt was to make the bracing thinner, without returning to scalloping. The result arrived in 1965, as the D-35. But instead of resurrecting the old Martin tone, they invented a new kind of Martin tone, which is why the D-35 remains very popular today, with its 1/4" non-scalloped braces.
It wasn’t for another decade that Martin released the original HD-28, which brought scalloped bracing back to the Martin Dreadnought design in 1975. The H stood for “Herringbone D-28,” because that had become the popular way to describe the prewar version of the iconic D-28. Otherwise, it was identical to the contemporary D-28. The two models continued to be very popular, with HD-28 out-selling the D-28 despite its higher price.
When Martin started accepting custom orders more regularly, they were immediately beset with requests for an HD-28 that had even more prewar features. These appointments typically included diamond fretboard markers, open back tuners, V necks, and the most pre-war feature of them all, forward-shifted bracing. Until 1939, Martin placed the center of the X-brace about one inch from the sound hole, so there was more area left unbraced near the bridge plate than on later Martins, resulting in an increase in bottom end resonance and further accentuation of the overall reverberating tone. And being smart at their art, Martin started offering a guitar with all of those retro features, which became the HD-28V and led to their very successful Vintage Series of the 1990s and beyond.
Despite their popularity, there were many more guitarists who didn’t care for vintage V necks, but wanted the awesome good looks and tone of those Vintage Series models. And so Martin decided to phase out them out, while incorporating their best loved specifications into their Standard Series counterparts.
First there was the 2016 D-18, which was identical to the mohogany D-18V with its tortoise binding and pickguard and other Vintage Series specs like forward-shifted, scalloped braces, but which was given the modern Modified Low Oval neck profile and High Performance fingerboard taper – the combination most ordered via the Custom Shop. The mahogany 000-18 got a similar makeover, and both models received huge increases in sales. Rumors then arose about the fate of the venerable D-28 with its luscious rosewood back and sides.
In 2017, the D-28 was refreshed to become the model you see today. Chris Martin did not want to change it too much since it remained as popular as it was. But he did go for the addition of forward-shifted bracing, which increases the bass response and overall bottom-end warmth. And the D-28 was also converted to the new neck shape and fretboard taper. And in 2018, Martin retired all Vintage Series models and converted the entire Standard Series line up to the High Performance neck, but otherwise they were given cosmetic features to bring back vintage Martin styling to the main Standard Series models.
So the HD-28 now has the forward-shifted, scalloped bracing and pre-war styling of the now retired HD-28V, but with the comfort and playability of the versatile, twenty-first century neck and string spacing. The D-28 has the same neck but retains the classic looks of post-WWII Style 28 and the non-scalloped braces that originated in the same era. And it remains almost as popular as the HD-28, partly because it is more affordable, but also because it has its own unique voice in the choir of Martin’s unmatched tone.
And if you check out the replay of the two-plus hour symposium, you will hear direct comparisons using the same mic in the same session, and learn how both models are well loved by many people, and why they are so similar in design and materials, yet are truly unique from one another. Which will you decide you love most? The D-28? Or the HD-28? We would love to hear from you about your reasons why!