An acoustical study on double bass bridge height adjusters

Abstract

A study on double bass bridge height adjusters was made using local and international surveys, a listening test survey, and sound spectrum analysis to learn more about the acoustical properties of various bridge adjusters and their current use. A questionnaire sent via e-mail to members of the International Society of Bassists confirmed that preferences and opinions about adjusters vary widely, though some general tendencies are recognizable. Responses also gave some indications why approximately 60 to 80 bassists use bridge adjusters, while adjusters in central Europe are rarely seen. Computerized listening tests showed that all types of bridge height adjusters cause an audible difference in sound compared to a bridge with no adjusters, and that individual models and materials have unique tonal characteristics. Finally, a digital sound analysis was made comparing a bridge with no adjusters to the same bridge fitted successively with six types of bridge height adjusters. The analysis showed that bridge height adjusters make a significant difference in pizzicato decay time depending on the model and material in question, and FFT spectrum analysis of bowed tones showed the sound characteristics of bridge height adjusters throughout the range of the double bass.