Sounding boards do not amplify every frequency via resonance
Evidence
Perhaps all the overlapping resonances explain the legendary effectiveness of sounding boards: every frequency is enhanced by resonance! However, we already know this idea is quite fallacious, because of the average power theorem (see section 11.2). Resonances rob surrounding regions of power in order to enhance themselves; this translates to a zero-sum game when they crowd together too closely. Apart from fluctuations, a drive delivers power to the board that is the same as if the board were infinite in size and returned no echoes from its edges. — Eric J. Heller, Why You Hear What You Hear- An…, 1153
Categorization
Category: Contrarian or Surprising Claims
- XREF: Directly extends the average power theorem established in section 11.2 of this book.
- SHARE: For a luthier or instrument-builder friend: the board doesn’t boost power, it only sculpts fluctuations.
Related
- Resonances compete for power as a zero-sum game when crowded together. (similarity 0.81)
- Over-confining sound in resonators can backfire through internal dissipation. (similarity 0.81)
- Driving a sounding board near a clamped edge produces antiresonance (similarity 0.81)
- Soundboards deliberately avoid isolated high-Q resonances (similarity 0.80)
- Power fluctuations persist even where resonances overlap completely (similarity 0.80)
- Soundboards are designed to minimize short-circuiting by lowering critical frequency (similarity 0.79)
- Smaller soundboards stay more resonant because Schroeder frequency scales inversely with size (similarity 0.79)
Broader Connections
- Clarinet sound still contains even harmonics the resonator does not support
#exemplifies(0.85) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1255 - Even harmonics appear in clarinet sound despite its closed cylindrical resonator
#exemplifies(0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1228 - A piano soundboard is reverberant, not resonant, above 500 Hz
#corroborates(0.80) — Eric J. Heller, Why You Hear What You Hear- An…, 1817 - Mixed-end tubes resonate only at odd multiples of the fundamental frequency
#exemplifies(0.75) — David Howard, Jamie Angus, coustics and Psychoacoustics, 405