A 14-fret Martin 000-15M and its 12-fret counterpart, the 000-15.
First, a quick history lesson. In the world of guitar luthiery, the 14-fret guitar—where the neck attaches to the body at the 14th fret—is a relative newcomer. When Martin started making acoustic guitars in 1833, they had 12 frets free of the body with a slotted headstock. At least part of the reason for this was that gut-string Spanish guitars, which were so influential in the development of the modern acoustic, had that same arrangement. Even nowadays when classical guitar builders regularly experiment with wood combinations and bracing patterns, they almost universally build guitars that have 12 frets.
By the early 1930s, guitars were popularly included in ensembles alongside woodwinds, brass, and banjos, which left many guitarists searching for ways to cut through the mix. In order to help those players carve out more sonic space, Martin started building 14-fret dreadnoughts in 1934. These guitars had a brighter and louder sound than their 12-fret counterparts, allowed for further access up the fretboard, and could hold their own against hard strumming while delivering single-note runs with clearer articulation and definition. Soon, the industry was rapidly making the transition to 14-fret models, and today they dominate the acoustic guitar landscape.
Because both 12- and 14-fret models have unique and desirable tonal qualities, it's not a surprise that many guitarists find both to be useful tools in their musical arsenal.
Structurally, changing a guitar from 12 to 14 frets may seem as simple as shortening the upper bout so the body meets the neck two frets higher, and Martin did exactly that with some models. Other designs included lengthening the neck by one fret and moving the soundhole closer to the bridge, as well as increasing the scale length to allow further variations on bridge and soundhole placement.
It's important to note that these changes are far from cosmetic. Each variation requires new bracing placement and results in unique tonal qualities.
So, which is better, a 12-fret or 14-fret guitar? The answer depends on what kind of music you play and the tone you want to achieve. Classical guitars continue to have 12 frets to the body in part because it places the bridge in the center of the lower bout, based on a traditional scale length of 25.6" (650 mm). This placement tends to maximize the ability of the top to vibrate, which can create that complex, almost pianistic tone that we associate with the classical greats. But strumming this kind of guitar can cause that rich tone to sound muddy and indistinct. Thus, fingerstyle players may find a 12-fret tone very satisfying, while a bluegrass artist or singer-songwriter may find it too subtle, bass-heavy, or unfocused when pushed. Beginners and smaller players may find that 12-fret guitars are easier and more comfortable to play, since their fretting hand doesn't have to extend quite as far to reach open position.
In the end, it comes down to tone, aesthetics, and what feels right for the player. Do you want greater access above the 12th fret? Are you playing primarily fingerstyle or with a pick? What do you find more comfortable to hold? Because both 12-fret and 14-fret models have unique and desirable tonal qualities, it's not a surprise that many guitarists find both to be useful tools in their musical arsenal. And while the 14-fret is the clear winner in terms of sales volume, there will always be a place for the time-tested 12-fret.
A 14-fret Martin 000-15M and its 12-fret counterpart, the 000-15.
When we are designing new guitars, we start with the player in mind. We try to draw a picture of the person we're trying to create this guitar for and understand what they want to do with it. Then, we work around that to decide if it will be 12-fret or 14-fret. It almost always comes out as a 14-fret, because they are so much more popular than the 12-fret in the current market.
But 12-fret guitars do still have plenty of fans. In fact, Fred Greene has a real soft spot for 12-fret guitars, and one of his favorite guitars in the Martin Museum is a 12-fret dreadnought. It is one of the most incredible sounding guitars in the whole collection. In his office, Fred keeps a Martin 00-28 VS, which is a 12-fret nylon that he just loves.
We were thinking differently about all this when we were designing the SC-13. We said, "Hey, you know, we want some of that clean, articulate voicing of a 14-fret, but we want to get the comfort of a 12-fret." We split the difference and we did a 13. It was the perfect compromise to get the playability and the sound together in one guitar. So, 12-fret vs. 14-fret? Perhaps the answer is 13 instead!
Large vs. Small
For the purposes of this discussion, let’s define a large acoustic guitar as a dreadnought or jumbo and a smaller acoustic as any instrument with a 000 or OM (orchestra model) body or smaller. People expect big guitars to have a big sound, and expect small guitars to be somehow diminished in tone. The paradox is that smaller instruments can be disproportionately and shockingly powerful in their volume. In addition, smaller guitars can possess a better balance between bass and treble. Without excessive bass overtones or woofiness, smaller guitars can be less prone to feedback onstage, and because it is easier to add bass than subtract it in the studio, smaller guitars are typically capable of producing a cleaner recording.
Guitars can vary in scale length, and scale length has an impact on string tension. I am often asked to explain the differences between the traditional 000 guitars versus the OM. Both guitars look more or less the same, but the 000 is traditionally short scale (24.9") while the OM is long scale (25.4"). So what impact do these different scale lengths have upon each of these sizes?
Most guitar players know that the scale length of a stringed instrument is basically the distance between the nut and the saddle. Say that you’re playing a 25.4" or 25.5" (long) scale guitar. Even with light gauge strings, the strings are tight and the tonal response has a lot of punch. Now, if you take a capo and put it across the first fret, you are in effect shortening the scale length by almost 1-1/2". It’s obvious that now all of the notes on the neck are a half step above standard EADGBE tuning. To get the notes back to standard tuning, you must tune each string down a half step. What’s happened? The strings are now noticeably looser, more sensitive to the touch, more bendable, with perhaps a bit less volume or punch.
So in the simplest terms, a player who wants the greatest volume and projection might gravitate toward a longer scale instrument, while a player who wants the more delicate expressiveness of note bending might prefer a shorter scale instrument.
- Tonewoods. In general, resonant woods like rosewood accentuate the bass response. Lighter woods like mahogany influence the treble response. Harder woods like maple aid in projection.
- Size. Smaller guitars typically accentuate the high-end trebles. Larger guitars typically impact the more resonant bass frequencies.
- 12 versus 14-fret bodies. The extra internal air cavity above the soundhole on 12-fret guitars typically adds hollowness to the tone that is advantageous for fingerstyle techniques, but is not always good for rhythm strumming.
- Scale length. Longer scale lengths at the same pitch put strings under greater tension. Shorter scale lengths can be tuned up to higher pitches.
- Strings. Obviously, lighter strings are under less tension than medium strings—lighter stings bend easier and are lighter to the touch. Medium strings are stiffer with more volume.
I’ve heard many singer-songwriters say that they prefer the bassy warmth of the large dreadnought body as an appropriate accompaniment to their vocals. I’ve heard just as many fingerstylists and recording studio artists extol the virtues of smaller-bodied guitars for their clarity. You can acquire an assortment of different guitars to suit the variety of your playing needs, or gradually focus on a particular size and shape.
My best advice is to pick up and play as many different guitars as you can. Each instrument has its own personality. Having a basic understanding of how the many variables impact the tone and projection of an instrument will help you focus on what guitar is most right for your particular playing style.
[Updated 12/1/21]