Plugging In: Acoustic Guitar Pickups and Their Pros and Cons

Amplifying an acoustic guitar presents a unique challenge, and many experts have dedicated years to developing effective solutions. With numerous pickup options available, selecting the right one can be overwhelming. To help navigate these choices, it is important to consider factors such as pickup type, active or passive systems, reversibility, and the player’s style and intended use.

Piezo vs. Magnetic Pickups

The first major decision when choosing a pickup is whether to go with a piezo or a magnetic system.

Piezo Pickups are made from materials that convert vibrations into electrical signals. They are typically installed under the bridge saddle or adhered to the underside of the guitar’s top. Since piezos capture the wood’s vibrations, they are known for delivering a more natural and authentic acoustic tone. However, the quality of sound depends heavily on installation—poor placement can result in uneven response, dead spots, and other inconsistencies. For best results, professional installation is recommended.

Magnetic Pickups are usually housed in a rectangular shell that clamps onto the soundhole near the fingerboard. Unlike piezos, these pickups sense string vibrations rather than body resonance, making them sound closer to electric guitar pickups. While some players prefer this tonal quality, magnetic pickups are particularly useful for their feedback resistance, which is beneficial in louder performance settings. Additionally, they tend to work well with effects pedals. Popular models include the Fishman Rare Earth and L.R. Baggs M1, both available in active and passive versions.

Active vs. Passive Pickups

Active Pickups require onboard power, typically from a 9-volt battery. Active piezo systems are the most common, as they offer consistent performance and a stronger, more balanced signal. Piezo transducers require a high-impedance input to maintain their full frequency range, and many amplifiers or effects units lack the necessary impedance to optimize passive piezo output. Active pickups solve this issue by incorporating a built-in preamp, ensuring stable and high-quality sound across various setups. The primary drawback of active systems is battery maintenance—some guitars feature external battery compartments, but most require loosening the strings to access the battery inside the guitar.

For those who prefer to avoid the weight, cost, or upkeep of an active system, Passive Pickups provide an alternative. The K&K Pure Mini is a popular choice among passive piezo systems. While passive pickups are more sensitive to the input they are plugged into, they offer a reliable, maintenance-free option. However, they often lack onboard volume and tone controls, requiring an external preamp to achieve the best performance.

Reversibility and Installation Considerations

Whenever modifying a guitar, it’s essential to consider whether the installation is reversible and how it may impact the guitar’s value.

Most pickups use an output jack that replaces the guitar’s endpin, requiring the endpin hole to be drilled to a larger 1/2-inch diameter. This is a standard modification that most players accept due to its practicality. However, for those who wish to avoid drilling, some magnetic pickups feature long cables that extend from the soundhole to a standard 1/4-inch plug, though these can be cumbersome.

Other modifications vary depending on the pickup type:

• Undersaddle piezo pickups require a small hole to be drilled in the saddle slot, which is a minor alteration but should be done carefully to avoid damaging internal braces.
• Body/top sensors are glued or taped to the underside of the guitar’s top. While effective, these pickups can be difficult to remove, potentially causing damage to the wood or the pickup itself.
• Side-mounted preamps offer onboard EQ, tuners, and other features but require cutting a hole into the guitar’s side, making this modification irreversible. With many non-invasive options available, side-mounted preamps are becoming less common.

Magnetic pickups attach to the soundhole using padded jaws, but improper installation or excessive tightening can scratch or dent the top. It is crucial to ensure a proper fit to prevent damage.

Choosing the Right Pickup for Your Playing Style

The best pickup choice depends on how and where you play.

• For quiet settings and recording, top-mounted sensors provide more detail and acoustic character. The L.R. Baggs HiFi system is a standout in this category, though it is more susceptible to feedback.
• For live performances and ensemble settings, undersaddle piezos are a reliable option due to their feedback resistance and ability to minimize handling noise. Active undersaddle pickups often include onboard controls for convenient volume and tone adjustments.

Hybrid Pickup Systems

For versatility, hybrid systems combine different sources—such as piezo and magnetic pickups or piezo and internal microphones. These systems, like the L.R. Baggs Anthem, allow players to blend signals for the best balance in different environments. While they offer superior flexibility, they tend to be more expensive and require more involved installations.

Final Thoughts

Finding the right pickup for your guitar requires careful consideration of tonal preferences, playing conditions, and installation factors. A mismatched pickup and amplification system can lead to an unsatisfactory experience, so it’s worth taking the time to choose wisely. Your Martin 000-15M is a great guitar that, with the right pickup, can deliver excellent amplified performance.