Standing-wave thinking applies only at low frequencies in small rooms

Evidence

As a result, as frequency increases it becomes progressively less useful to think about regular patterns of standing waves in rooms, but rather to think in terms of irregular patterns of constructive and destructive acoustical interference caused by numerous reflections traveling in many directions. — Toole, Floyd E, Sound reproduction- the acoustics and…, 474

Categorization

• DEFINE: Explains the meaning of the transition from modal (standing-wave) to ray-acoustical (reflection/interference) thinking as frequency rises.