The Impact of Pickup Height on Guitar Sustain and Output

The height of your guitar's pickup can significantly affect its sound, particularly in terms of sustain and output level. While the relationship may be subtle, understanding the principles involved can help you optimize your guitar's performance.

Mathematical Principles: Inverse Square Law

Magnetic force follows an inverse square law with distance, similar to Coulomb's Law. This means the force is inversely proportional to the distance squared. This relationship has important implications for the sound produced by your guitar.

Basic Math and Implications

At half the distance, the magnetic force is four times as strong. Conversely, at double the distance, the magnetic force is only one-fourth as strong. This principle applies to how pickups interact with guitar strings.

The closer the pickup is to the string, the more it can influence the string's vibration. This impacts the sustain of the note and can also affect the output volume. Even with a volume switch, the basic principles of magnetic force still govern these behaviors.

Pickup Design and Its Impact

The design and positioning of the pickup also play a significant role in the sustain and output level of a guitar.

Humbuckers and Stratocasters

Let's consider two typical guitar pickup types: Gibson humbuckers and Fender Stratocasters' single coils.

Humbuckers

A typical humbucker has the magnet positioned at the bottom of the pickup. When you adjust the pickup closer to the strings, the magnetic force increases, which can dampen the string's movement. This can reduce sustain but can also increase the output level. However, the change in distance is generally small, making the impact minimal.

Stratocasters

The Stratocaster's single coils have magnetic pole pieces that extend to the top of the pickup, often protruding from the cover. These pole pieces start closer to the strings and can be adjusted more closely without significantly impacting string movement. However, if the pickup is too close, it can interfere with the string's vibration, causing pitch issues known as "strat-itis."

Strat-itis: A Cautionary Note

"Strat-itis" is characterized by dissonant overtones, particularly noticeable on the lower strings as you play up the fretboard. This condition can make playing more challenging and less enjoyable.

Optimal Settings for Sustain and Output

A careful balance between pickup height and magnetic strength is essential. Too close to the strings can reduce sustain and introduce unwanted noise and pitch changes. Conversely, positioning the pickup too far away may decrease the output volume and increase noise.

Experimenting with different pickup heights, both by ear and with a precision gauge, can help you achieve the optimal setting for your playing style. Many guitarists find that a bit of trial and error is necessary to find the perfect balance.

Conclusion

The relationship between pickup height and guitar sound is a nuanced one, influenced by the inverse square law and the design of your pickups. While the effects may be subtle, making these adjustments can significantly impact your playing experience. By understanding and experimenting with these settings, you can greatly enhance your guitar's performance.