Speaker spacing below half a wavelength to avoid aliasing is practically prohibitive

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 (#contradicts, via linked claim)

How big do the cells need to be? There is no single answer to this question, because a few smaller cells can often be replaced by one bigger cell, but there is a limit: the cells need to be much smaller than the shortest important sound wavelength, so that the information that they are being pushed on one side travels to the other sides in a time much shorter than a period of the sound. Usually a few centimeters or, at worst, a few millimeters on a side (giant on the scale of the distance between atoms and molecules in air) will suffice. — Eric J. Heller, Why You Hear What You Hear- An…, 96 (#expands, via linked claim)

Categorization

• XREF: connects to: Six or more equally spaced speakers imitate a diffuse array well; four do not; Array spacing beyond half a wavelength causes spatial aliasing with multiple lobes — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2890; Perfect pattern control across the audio range is physically infeasible due to aliasing cost (+1 more)

Broader Connections

• Perfect pattern control across the audio range is physically infeasible due to aliasing cost #expands (0.85)
• Array spacing beyond half a wavelength causes spatial aliasing with multiple lobes #contradicts (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2890
• Air cells for sound simulation must be far smaller than the shortest wavelength #expands (0.72) — Eric J. Heller, Why You Hear What You Hear- An…, 96