Optimal woofer placement makes boundary distances as different and non-multiple as possible

Evidence

The approach offered by Allison (1974, 1975) and Ballagh (1983) involves choosing the position of the loudspeaker with respect to the boundaries in a manner that minimizes the variations in frequency response at the listening locations. Obviously, the goal is to arrange for the woofer-to-boundary distances, floor and walls, to be as different as possible, while not being multiples of each other. The more different these distances are, the less will be the effect. Finding an optimum result may involve some trial-and-error in practical listening. It may also result in visually unappealing, asymmetrical, or incorrect (in terms of stereo or multichannel imaging) locations for the loudspeakers. — , Toole, Floyd E - Sound reproduction-…, 1068

Categorization

• DEFINE: States the actionable principle of the Allison/Ballagh placement method for minimizing adjacent-boundary frequency response variation.
• XREF: connects to: Surface wall mounting creates a comb-filter cancellation at the woofer-to-wall round-trip wavelength; Optimizing any two of room, subwoofer, and seating yields the third; Optimized multi-sub systems can use much smaller subs at some locations (+6 more)

Broader Connections

• Avoiding commensurate room dimensions prevents overlapping modal frequencies that cause acoustic problems #corroborates (0.95)
• Room mode coupling depends on source and listener positions, not frequency #expands (0.85)
• Comb-filtering undulations from room reflections move to bass and become inaudible #expands (0.75)