At low frequencies only drivers and ports define a loudspeaker’s effective source size

Evidence

This appendix has presented the basic Fourier relationship between the far-field polar response and the near-field illumination of the aperture. It has demonstrated its utility in a variety of electroacoustic applications. In particular, it is possible to derive some useful relationships between the size of the speaker, with respect to wavelength, and its directivity performance versus frequency—in particular that for directivity, size really does matter! — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2946 (#expands, via linked claim)

Categorization

• XREF: connects to: Larger speaker size relative to wavelength enables higher directivity — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2946

Related

• Larger speaker size relative to wavelength enables higher directivity (similarity 0.94)
• A speaker’s coverage angle roughly doubles for each octave below its minimum directivity frequency. (similarity 0.90)
• Radiation directivity depends on wavelength relative to source size (similarity 0.89)
• Acoustic wavelength size relative to objects governs how sound interacts with them (similarity 0.88)
• Speaker drivers’ directivity at high frequencies causes spectral dips in the reverberant field (similarity 0.88)
• Directivity depends on wavelengths fitting across the radiating aperture (similarity 0.88)
• Increasing speaker directivity reduces the reverberant field like a tone control does (similarity 0.87)
• Digital signal processing made constant-directivity array loudspeakers practical and popular (similarity 0.87)
• Small loudspeakers radiate omnidirectionally because they are small relative to wavelength (similarity 0.85)
• Smaller drivers radiate more omnidirectionally at a wider frequency range (similarity 0.85)
• Large radiating surfaces become highly directional at high frequencies (similarity 0.84)
• As wavelength shrinks below diaphragm size, speakers beam and off-axis sound diverges spectrally (similarity 0.82)
• Sound diffracts strongly only when wavelengths exceed opening size (similarity 0.82)
• Reflection and diffraction of sound both depend on object size relative to wavelength (similarity 0.82)
• Speaker size dictates the lowest frequency sustaining a given coverage angle (similarity 0.81)

Broader Connections

• Larger speaker size relative to wavelength enables higher directivity #expands (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2946