Lateral wall reflections arrive attenuated by inverse-square law distances

Evidence

The curves for the specific angles, 40° and 80°, would have been lower than those shown but the comparative levels are probably realistic. These curves were lowered by the amount required by the inverse-square law, 3.6 dB for the adjacent-wall reflection and 7.2 dB for the opposite-wall reflection—both compared to the direct-sound arrival, the on-axis curve. The curves are truncated below 500 Hz because at lower frequencies, room modes and adjacent-boundary effects progressively dominate. — Toole, Floyd E, Sound reproduction- the acoustics and…, 437

Categorization

• DEFINE: Clarifies how off-axis loudspeaker curves approximate wall-reflection strengths (3.6 and 7.2 dB down) and the low-frequency truncation rationale.