Abstract: A stringed instrument with sympathetic strings is provided that includes (in addition to the primary elements corresponding to standard instrument elements) sympathetic strings, one or more supplementary bridges, a supplementary string termination assembly, and a set of supplementary tuners. The sympathetic strings are stretched diagonally across the soundboard of the instrument, with one end of each string attached at a supplementary tuner and the other end attached at a supplementary string termination assembly. The sympathetic strings are spaced by the supplementary bridge(s) a sufficient distance from the soundboard to prevent interaction with it during vibration of the string during playing. The sympathetic strings are activated by sound vibrations created by the bowed primary strings, may additionally be activated by plucking or strumming, and may be manually muted.

Abstract: A string-replacement assembly may be installed within an inner cavity of a body of a guitar. The assembly includes a plurality of cartridges each configured to contain a supply of replacement string therein, corresponding to a particular gauge of string for the guitar. Each supply of replacement string is rotatably mounted within a cartridge. A free end of each supply of the replacement string can be threaded through an exit opening in the body of the guitar for installation on a topside of the guitar. When string breaks or needs to be replaced on the topside of the guitar, a portion of the supply of the replacement string may be readily advanced from a corresponding cartridge to a desired length, and installed in a playing position on the topside of the guitar, to replace a removed portion (associated with the breakage or replacement) of the string.

Abstract: A device and method for balancing the torque created by strings on musical instruments includes a bracket attached to the bottom of the bridge, an adjustable brace attached to the neck and residing within the body of the instrument and a tension string connecting the bracket and brace such than it offsets torques created by the strings that create the music. The device counteracts the tension created by guitar strings and provides enhanced vibration of the instrument soundboard.

Abstract: An internal, acoustic enhancement device attached to a standard, conventional stringed musical instrument without causing damage thereto. The internal acoustic enhancement device includes two or four tensioned springs disposed in a V-shaped or X-shaped configuration removably attached to vibration blocks secured within the soundbox of the stringed musical instrument.

Abstract: A device for changing the timbre of a stringed instrument of the violin or viol family. The device includes a plurality of sympathetic strings, rigidly fixed at opposite ends in a frame suspended over a sound board of the instrument. A javari bridge is mounted on the sound board, a distance from a main bridge, with the sympathetic strings passing over the javari bridge. When the sympathetic strings are set into vibration by the main strings, the javari bridge brings out upper harmonic vibrations in the sympathetic strings, changing the timbre of the instrument. The javari bridge also makes the upper harmonic vibrations more audible and shortens the period of vibration, avoiding the dissonance associated with sympathetic strings strung over a conventional bridge. When the javari bridge is stepped, the sympathetic strings may be strung in tiers, allowing more strings to be strung in less space and expanding the harmonic sounds produced by the instrument.

Abstract: A sound reverberator for a string musical instrument having a sound box and strings tensioned over a saddle member of a bridge piece connected to a top wall of the sound box. The reverberator comprises one or more pre-tensioned springs secured internally of the sound box. A metallic transfer member is secured to a free end of the spring internally of the sound box. The transfer member is displacedly supported under the strings by a finger actuated displaceable support element for releasably engaging the springs of the musical instrument to transfer vibrations from the strings to the one or more metal springs whereby to produce sound vibrations internally of the sound box to modify the tonality of the sound generated by the sound box as a result of setting the strings in vibration.

Abstract: A counter pressure system for use in a stringed instrument of the type played with a bow for improving the tone of the instrument in both volume and in quality. The system includes the main or melody producing strings and one or more counter pressure strings that are arranged to accept at least part of the pressure from the main strings and transfer it away from the main bridge. The relieved pressure is redistributed by the counter pressure system in a manner that extends the quality of sound produced by the instrument. In practice, part of the total string pressure is translated to the sound box via the main bridge while the remaining pressure is imparted to the box via an auxiliary bridge located forward of the main bridge. A sounding post is located under one foot of each bridge which, in the case of a violin, would be the foot on the E string side of the instrument.

Abstract: A stringed instrument, such as a guitar, is provided with one or more auxiliary strings which are parallel to the regular strings of performance and between the regular strings and the sound box or body to be actuated under the influence and vibrations of the regular strings.