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Double basses on the stage floor: tuning fork-tabletop effect, or not?
Knut Guettler1, Anders Askenfelt, Anders Buen
1Norwegian State Academy of Music, Eilins vei 20, N-1358 Jar, Norway. knut.guettler@tele2.no
The Journal of the Acoustical Society of America
|January 28, 2012
Summary
Double basses can benefit from compliant stage floors, enhancing low-frequency sound. Experiments confirmed this tuning fork-tabletop effect in concert halls, boosting sound pressure levels.
Area of Science:
- Acoustics
- Musical Instrument Physics
- Architectural Acoustics
Background:
- The tuning fork-tabletop effect describes amplified vibrations when a tuning fork's base is placed on a resonant surface.
- The potential application of this effect to double basses and stage floors for low-frequency enhancement was unexplored.
Purpose of the Study:
- To investigate if double basses benefit from compliant, radiating stage floors for low-frequency sound production.
- To assess the conditions necessary for the tuning fork-tabletop effect to manifest with double basses on stage floors.
Main Methods:
- Field experiments were conducted in five concert halls.
- Measurements included mechanical input impedance of three double basses and five stage floors.
- Vibration velocity transmission and sound radiation efficiency of stage floors were analyzed.
Main Results:
- Mechanical impedance matching between double basses and stage floors was evaluated.
- Vibration transmission through the end pin and floor radiation efficiency were quantified.
- In Lindeman Hall, Oslo, conditions for the tuning fork-tabletop effect were met, yielding a ~5 dB increase in sound pressure level between 40-60 Hz.
Conclusions:
- The tuning fork-tabletop effect can occur between double basses and compliant stage floors.
- This phenomenon can significantly enhance low-frequency sound radiation in concert halls.
- Stage floor design is a critical factor for optimizing double bass performance in the low-frequency register.
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