Effective sound diffusion demands surface depths proportional to the target wavelength
Evidence
As we have seen, these sequences achieve their performance by spreading the phase of the reflected wavefront over at least one cycle of the incident wavefront. In order to do this, their maximum depth must be λ 2 at the lowest design frequency. This means that to achieve diffusion a reasonable depth is required. For example, to have effective diffusion down to 500 Hz a depth of 34 cm (13.5 inches) is required. To get down to 250 Hz one would — David Howard, Jamie Angus, coustics and Psychoacoustics, 2143
Categorization
Category: Factual Claims
- SEED: Concrete numbers (34cm for 500Hz) could anchor a practical article on acoustic room treatment for home listeners.
Related
- Low-frequency sound diffusion requires impractically deep diffuser wells (similarity 0.91)
- Practical diffusers need depth set by wavelength of the lowest frequency treated (similarity 0.89)
- Acoustic diffusion needs surface bumps sized between an eighth and a half wavelength (similarity 0.89)
- Effective sound diffusers ideally need no physical depth at all. (similarity 0.86)
- Effective sound diffusion requires bumps sized between an eighth and half a wavelength. (similarity 0.86)
- Modern acoustic diffusion uses mathematically structured well patterns (similarity 0.85)
- Sound diffracts strongly only when wavelengths exceed opening size (similarity 0.83)
- Wall projections must exceed one-seventh wavelength to scatter sound usefully (similarity 0.82)
- Element-based acoustic models scale poorly as wavelength shortens (similarity 0.82)
- Diffuser depth sets a lower frequency below which no scattering occurs. (similarity 0.82)
- Diffusion depth scales proportionally with wavelength, so lower frequencies demand deeper surfaces (similarity 0.82)
- Regularly spaced surface bumps diffuse sound only at specific frequencies (similarity 0.81)
- Reflection and diffraction of sound both depend on object size relative to wavelength (similarity 0.81)
- Diffusor effectiveness in small listening rooms lacks subjective validation (similarity 0.80)
- How bumps reflect sound depends on bump height relative to wavelength. (similarity 0.79)
Broader Connections
- Acoustic diffusion needs surface bumps sized between an eighth and a half wavelength
#corroborates(0.95) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2071 - Diffusion depth scales proportionally with wavelength, so lower frequencies demand deeper surfaces
#expands(0.92) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2096