A loudspeaker’s size sets a floor below which it cannot be directive

Evidence

However, irrespective of the technology used, there is a fundamental lower limit on the frequencies at which the speakers are directive that is deter­ mined by their size. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2489

Categorization

• XREF: Connects to the book’s Chapter 1 treatment of diffraction and scattering (Sections 1.5.9-1.5.10), which this sentence explicitly points back to.