Most acoustic guitars have 19-20 frets compared to electric guitars which usually have at a minimum 21 frets. So, why the difference?
Should we as acoustic guitarists feel short changed? Perhaps not. In today’s article we’ll take a closer look at why acoustic guitars have less frets than electric guitars and why we probably wouldn’t want it any other way.
Key Points: Acoustic guitars have less frets than electric guitars because it’s difficult to comfortably access anything higher than the 17th fret on an acoustic guitar due to the body of the guitar being larger, resulting in greater projection, but preventing upper fret access. Acoustic guitars also do not transfer vibrations as effectively from the strings to the soundboard when playing in higher positions due to the vibrating string length being much shorter.
While the answer above explains the main reasons why acoustic guitars have less frets than electrics, it’s actually a little more complicated than this, and if you are into guitars, interesting also, as I will explain in the following sections.
Body Size and Fret Access
One noticeable difference between acoustic and electric guitars is the size of the body.
And, while there are many small body acoustic guitars including Parlor and Concert size guitars, these guitars are typically not as loud as larger body acoustic guitars such as Dreadnoughts or Jumbos.
For the most part the body of an acoustic guitar is substantially larger than the standard electric guitar, and also has more depth.
There’s a good reason for this.
Electric guitar bodies, due to the electronics playing the primary role in how the guitar sounds, have little to do with volume or tone, with the exception in some cases of sustain, particularly if the pickups are not wax potted, and incorporate more of the resonance of the body.
With this in mind luthiers who design and build electric guitars have the luxury of taking into account playability in terms of upper fret access, comfort (small body size = lighter body, along with comfortable body contours e.g. belly cut) and of course aesthetics.
The acoustic guitar however is a completely different story.
The body shape, size and materials used all combine to influence the projection and tonal characteristics of the guitar.
In this sense, the design of the acoustic guitar is far more of a delicate compromise between tone, comfort, playability and aesthetics, with aspects such as upper fret access considered not as important for a few different reasons.
The first, being where the neck joins the body and how this impacts upon upper fret access.
Most acoustic guitar necks join the body at the 14th fret, with some joining at the 12th fret (12 fret guitars), although this is a little less common.
As a result those upper frets e.g. from the 15th and upward start to become difficult to access with anything above the 17th fret unable to be fretted comfortably as per the rest of the neck.
With this in mind, for anyone with normal sized fingers and hand span, there’s really no point to acoustic guitars having more than 19 – 20 frets.
Electric guitars however typically have the neck joining the body much higher up the neck. For example both the Gibson Les Paul and Fender Stratocaster, arguably the two most iconic electric guitars, have their necks joining the body at the 17th fret.
On the Les Paul there is also a cutaway on the body providing easier access to the upper frets on the treble strings, and on the Stratocaster the body shape features two horns, allowing access to the upper frets across the neck.
Other electric guitars such as the Gibson Les Paul Junior, or ES335 have even better access to the upper frets with the neck not joining the body until the 20th fret or higher.
Why Upper Fret Access is Less important for Acoustic Guitars
If you consider how acoustic guitars are played compared to electric guitars the design of both makes a lot of sense.
For example, acoustic guitars rely on resonance and projection, as a result they require a large soundboard (top wood) that can vibrate and affect the air within the internal chamber of the guitar.
Sacrificing upper fret access for greater volume in this case is a worthwhile exchange. Besides, acoustic guitars don’t handle higher frequencies as well as electric guitars in most cases (more on this shortly) and are usually associated with strumming or fingerstyle guitar, whereas electric guitars are synonymous for wailing solos incorporating high notes.
Acoustic Guitars Don’t Sound great on the upper frets anyway
If you consider how the acoustic guitar projects sound from the body of the guitar, there is a transference of vibration (resonance) from the strings via the bridge to the sound board, this is essentially how the acoustic guitar projects sound.
If the strings alone were responsible for displacing the air sufficiently for us to detect sound the volume ammount to much. However, as the vibrations from the strings are transferred to the much larger soundboard of the guitar this displaces a lot more air particles resulting in greater amplitude (volume).
Much of this has to do with the length of string that is able to vibrate.
The higher up the neck we go, the shorter the string length able to freely vibrate and as a result the less resonance transferred to the soundboard.
This results in less volume and a thinner tone, that lacks warmth.
When compared to the electric guitar which relies on electromagnetism and the initial signal being amplified, there is quite a difference in how notes played in the upper region of the neck sound.
This is just another reason why acoustic guitars tend not to include frets higher than the 20th fret, whereas there are many electric guitars have between 21 and 24 frets, and even higher in some cases.
While it can be frustrating not always having decent access to these upper frets on the acoustic guitar, the design of the acoustic guitar must take into account far more than the electric guitar in terms of the size of the internal chamber of the body and it’s ability to project sound, along with other considerations such as string length on the upper frets and how those notes sound when played on acoustic. So next time you are wondering why your acoustic guitar has fewer frets than an electric bear in mind, when considering acoustic guitar design you probably really wouldn’t want this to change.