Array spacing beyond half a wavelength causes spatial aliasing with multiple lobes
Evidence
When the frequency gets high enough that the spacing between the point sources becomes greater than half a wavelength, the array becomes undersampled. Under these conditions, one gets spatial aliasing, which results in multiple main lobes. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2890
Categorization
- XREF: Spatial aliasing is the spatial-domain analog of temporal sampling aliasing familiar from digital audio — connects to the Shannon-Nyquist sampling theorem and the temporal aliasing concepts in earlier chapters. — connects to: Undersampled signals alias because high-frequency components mirror below the Nyquist frequency — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 404; Aliasing creates signal components that never existed in the original; Speaker spacing below half a wavelength to avoid aliasing is practically prohibitive (+3 more)
- corroborated: 2 independent passages support this claim — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2890
Broader Connections
- Standing waves arise when wall spacing equals half-wavelength multiples
#expands(0.75) - A finite source-to-wall distance creates a destructive interference null at the half-wavelength frequency
#qualifies(0.70)