An instrument’s output spectrum equals its input spectrum weighted by the body’s resonance response
Evidence
The output spectrum is derived by multiplying the amplitude of each component of the input spectrum by the response of the body of the instrument at that frequency. In the figure, this multiplication becomes an addition since the amplitudes are expressed logarithmically as dB values, and adding logarithms of numbers is mathematically equivalent to multiplying the numbers themselves. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1125
Categorization
- DEFINE: Explains the core filtering principle: output spectrum = input spectrum Ă— body response, with the log/dB trick making the multiplication an addition.