Boundary-image relationships hold only when wavelengths exceed source size and separation

Evidence

But there is more to be aware of. What is shown in Figure 13.1 happens only at wavelengths that are long compared to the source size and the separation distance. With respect to where we place loudspeakers or listeners relative to the boundaries of a room, this normally applies only at very low frequencies. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1457

Categorization

• DEFINE: States the wavelength-and-geometry validity condition that limits the classic image model.