Screwed-in, set-in neck or neck-through body?
An important feature in the construction of an electric bass is represented by how the two main parts of the instrument, body and neck, are connected together. There are three main types of connection, the two most common are those that provide the screwed neck (bolt-on neck) and the neck passing through the body (neck-through body), also called direct line, in which bridge, pickup and tuning machines are mounted on the same single piece (the through neck) to which the wings that form the body are glued.
BOLT-ON NECK
NECK-THROUGH BODY
It is a general opinion that the neck-through body gives more sustain to the instrument and a greater yield on the fundamental harmonics. It must be said, however, that much depends on the general quality of the materials used and that, when you find a magical combination between a screwed body and a neck, the bolt-on turns out to be, in my opinion, a winning solution with respect to all the parameters of the sound quality, especially when it comes to the sound clarity. As always when we talk about sound we enter the field of personal feeling.
One of the advantages of the neck-thru is that it allows easy access to the higher frets of the fingerboard, since there are no obstacles at the point where the neck meets the body, on the other hand, in case of neck problems, the bolt-on allows its replacement or modification without compromising the entire instrument.
The first electric bass in history to present the constructive feature of the neck-through body was the 1957 Rickenbacker Model 4000, conceived by the German luthier Roger Rossmeisl.
There is also a third important way of joining the neck with the body, that of the glued neck (set-in neck). More common in guitars (Gibson Les Paul, for example) than in the electric bass, it provides various possibilities for fitting and gluing the neck to the body. We often find it in the semi-acoustic and acoustic basses (in fact this joining system is the oldest one and it is used in the construction of all acoustic chordophones with neck of all ages, including those of the family of violin).
SET-IN NECK