Electric guitars and basses have magnetic pickups located between the bridge and neck below the strings. This design is the same, regardless of whether we speak of single-coil pickups, humbucking pickups, P90s, or other similar types. On the other hand, acoustic guitars and basses vary in terms of pickup arrangements since they have different body architectures.
Where are pickups located in acoustic guitars and basses? Magnetic pickups are normally located above the soundhole (they are called “soundhole pickups” for this reason.) Piezoelectric pickups are located either under the saddle (undersaddle transducers) or on the inside of the guitar (soundboard transducers).
In this article, we'll discuss these different pickup types and their positioning, touching upon the following bullet points:
- A detailed explanation of the different types of acoustic guitar and bass pickups and their positioning.
- Distinctions with electric guitar/bass pickup arrangements.
Types Of Acoustic Guitar/Bass Pickups (Classified By Location)
As disclosed above, acoustic guitar pickups are positioned a bit differently from electric guitar pickups, owing to the space limitations in the design and, in some sense, to their diverse mechanisms for producing discernible sounds.
Acoustic guitars ordinarily don't need pickups to be audible to smaller audiences. Occasionally, they need additional amplification not to be drowned by other instruments in large concert venues or to reach farther distances.
Usually, the best solution is to place a microphone, either on the guitar itself or on a stand, pointing towards the soundhole. Microphones, especially modern ones, are known for their superb sound fidelity, and they're guaranteed to amplify the notes with the greatest detail.
Related article: Best Microphones For Miking Acoustic Guitar
Despite all this, microphones will produce feedback when there are numerous other pieces of gear around. Furthermore, they will likewise pick up sounds from other instruments, muddying the whole output as an undesirable result.
Pickups grant the advantage of isolating the guitar's sound from the rest of the environment (somewhat), but not without considerable drawbacks, which we'll disclose as we move on.
There are typically three major types of pickups for acoustic guitars/basses, with differing positions:
According to the technology used, the last two can be classified as one type, but they're generally categorized differently due to the way they're placed relative to the guitar's build.
Since we're dealing primarily with pickup positioning, we won't go into detail regarding blended pickup systems, as they're basically a mix of microphone technology with one of the three pickups mentioned above. We will be skipping microphones as well because, technically speaking, they're not pickups.
Magnetic Pickups (Soundboard)
Magnetic pickups are usually positioned in the soundhole just below the strings. They are exceptionally easy to install, though the cables can easily get in the way unless you opt for a permanent installation, which will demand deep structural alterations to the guitar's design.
They work the same way as those found in electric guitars. The magnets and pole pieces are responsible for capturing the strings' movement. The coils translate the movement's energy into an electrical current that travels through the output jack to the amplifier.
These pickups normally deliver a very warm sound, but they lack some of the percussive undertones typical of acoustic guitars, resembling more the tone of an electric guitar.
Moreover, you would benefit from attaching strings with more magnetic properties (such as stainless steel or nickel) since the wound bronze or phosphor bronze strings will not be capable of interacting as well with the pickup's magnets.
A great feature of these pickups is their resistance to feedback compared to microphones. Still, they are less resistant than piezoelectric pickups in this regard, owing to the soundhole's impact on the magnets.
For acoustic basses, searching for these pickups can be challenging. Yet, it's not entirely impossible to craft homemade bass pickups or to find ways to fit acoustic guitar pickups into an acoustic bass soundhole (although some players report that they don't work too well because guitar soundhole pickups are optimized for bronze strings).
Piezoelectric pickups (“piezo” in short) are different from magnetic pickups in both positioning and the underlying technology.
They operate with crystals instead of magnets. These crystals measure the pressure produced by the strings and the wood. When the crystals are set in motion, they transform this pressure into electric signals.
The main advantage of these pickups over magnetic pickups is that they're not limited to the magnetism of the strings but can also catch the wood's vibration. This means that the tone rendered will be closer to the original acoustic sound projected by the soundhole.
Another great benefit of piezo pickups is their non-invasive nature. Some players may not even notice their presence, and the guitar's aesthetics are not disrupted.
As a downside, their installation can be a bit more complex, depending on the type and placement. Some electro-acoustic guitars/basses include piezos by default, saving players from all the trouble.
Piezo pickups can be divided into two categories (according to their installation spot):
- Undersaddle Transducer
As the name implies, they are installed under the saddles attached to the bridge. They produce a relatively high output, but their tone is a bit “quacky”, with a strong initial attack but not much sustain. They're also quite tricky to install.
- Soundboard transducer
A soundboard transducer is also a piezo pickup, but instead of being placed under the saddle, it rests on the soundboard itself.
Its installation can vary in complexity, and some models cannot be fully removed without damaging the guitar's finish. It can be placed at various positions across the soundboard, but the most common spot is the underside of the soundboard, on the bridge's rear.
The tone of a soundboard transducer is described as “woody” and profound since it interacts directly with the wood and the air molecules in motion inside the soundboard itself. However, its output is very low and requires a preamp module to boost the signal.
Differences In Pickup Arrangement Between Acoustic & Electric Guitar
In electric guitars, magnetic pickups are the general norm. The positions of the different pickups are meant to convey different tonal traits, but their technology and installation procedure will always be the same regardless. You can still find electric guitars/basses with piezo transducers or other pickup types, but they are exceptions.
In the case of acoustic guitars/basses, each pickup type has to be adapted and integrated into the traditional body design of the instrument and has different installation methods depending on the placement.
It should be stressed that these types of guitars and basses were not originally meant to have pickups equipped due to the fact that they don't operate principally on electricity but by way of air molecules. The pickups were commercialized to provide players with further amplification for specific contexts.
For more information on the differences between acoustic and electric guitar pickups, check out my article Electric Guitar Vs. Acoustic Guitar Pickups (+Bass Guitar).