Bass bar
The bass bar is a wooden strip in the body of string instruments . It is glued to the inside of the ceiling . The bass bar runs parallel to the strings and lies on the bass side of the instrument. The foot of the bridge on the bass side is above the bass bar.
Functions
The bass bar mainly amplifies the low frequencies and distributes them to the lower and upper bows of the ceiling. This reinforcement of the bass works by dampening the longitudinally propagating vibrations with a high frequency, since the vibrations of the treble strings do not have enough power to stimulate the top side, which is blocked by the bass bar, to vibrate. In contrast, the high-frequency oscillations running across the bass bar are not or only slightly damped. Thus, the bass bar contributes a large part to the balanced warmth of the sound of an instrument.
It also has a static function because it stabilizes the ceiling and thus distributes the pressure exerted by the bridge evenly over the entire ceiling.
construction
With older instruments, the bass bar was often "left standing" when the top was carved (so-called ejected bass bar).
Today, the bass bar is usually adapted to the carved ceiling vault and glued in. Some violin makers apply tension to the bass bar (so that it also arches the top), others reject this method and glue it in without tension.