Amplification is an important aspect when it comes to bass guitar. This instrument requires an amplifier for the frequencies of the vibrating strings detected by the pick-up. The amplifier takes these signals and converts them into louder and sometimes distorted tones. Then, these travel to the speaker so they can be heard. 

Regarding the pickups, a number of alternatives exist, patented by specific brands. “Precision” pick-ups, introduced with the Fender Precision Bass, or “P-style” pick-ups consist of two single-coil pick-ups. Each one offsets slightly along the body length so half of it sits underneath two strings. A pair is considered to be a single pickup since they’re wired together in a hum-bucking arrangement. This significantly minimizes the noise from surrounding electronic devices and mains power.

On the other hand, “Jazz” pick-ups, as developed for the Fender Jazz Bass, or “J-style” pick-ups are big eight-pole pick-ups that lie underneath all four strings. They are usually single-coil design, although there is a wide range of hum-bucking designs available. Traditionally, two of them are used, one near the bridge and the other one closer to the back. 

There are also choices of non-magnetic pickups. The use of non-magnetic pick-ups enables bassists to use non-ferrous strings such as nylon, brass, polyurethane, and silicone rubber. Both materials create different tones and allow for much shorter string lengths in the case of polyurethane or silicone rubber. The most common non-magnetic types are Piezoelectric and Optical pickups.

Inside the bass guitar

The innards of the bass guitar are not visible to the eye. They are concealed inside the instrument’s cavity and protected with plates. However, they’re essential to the sound and feel of the bass guitar. The truss rod is an adjustable metal rod that runs around the length of the bass guitar body. The truss rod controls the curvature of the neck and fingerboard and holds it secure. You can access it from the top or bottom of the neck if you need to adjust it.

The electronics of the bass guitar consist of a series of wires, potentiometers, and other essential electronic features that help translate the vibration of a string into sound. The electronics cavity usually sits under a plate on the back of the bass guitar body, or under the control keys. If the bass guitar has active electronics, a 9-volt battery connected to them is necessary. Such batteries sit in the same cavity as the electronics or in the opposite cavity, on the rear. They need replacing with a certain frequency.

Traditional electric bass guitars have four strings, tuned in the same way as double basses: E1–A1–D2–G2. Nowadays, however, there are a lot more choices: bass guitars with five, six, and more strings. In addition to the standard flat-wound strings, choices in strings now include a range of different windings and materials.