Loudspeaker position determines which room modes get excited, as with bowed strings

Evidence

Another name for these standing waves in a room is resonant modes, and the frequencies at which they occur are known as “modal frequencies.” Because the modes are spatially static, there will be a strong variation of sound pressure level as one moves around the room, which is undesirable. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1953 (#expands, via linked claim)

Between the orderly low-frequency room resonances, and the different higher frequency reflection/ray-acoustical behavior, is a transition zone, the middle of which, in large rooms such as concert halls and auditoria, would be defined as the Schroeder frequency or, as Schroeder himself calls it, the cross-over frequency fc (Schroeder, 1954, 1996): where T is the reverberation time in seconds, and V is the volume of the enclosure in cubic meters. The multiplier constant changed from the original 4000 to 2000 in the 1996 paper, emphasizing that this is not a precision calculation. — Toole, Floyd E, Sound reproduction- the acoustics and…, 475 (#expands, via linked claim)

Categorization

• XREF: connects to: Strike placement on a drum excites modes by their amplitude at that point; Where you strike a percussion instrument governs which modes sound; Plucking position on a string determines which harmonic modes are suppressed — David Howard, Jamie Angus, coustics and Psychoacoustics, 1107 (+3 more)

Broader Connections

• Room mode coupling depends on source and listener positions, not frequency #expands (0.95)
• Spatially static resonant modes cause sound level to vary across a room #expands (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1953
• A transition frequency separates modal from ray acoustical behavior in rooms #expands (0.75) — Toole, Floyd E, Sound reproduction- the acoustics and…, 475