Experimental constraint forced a dipole approximation rather than true omnidirectional speakers

Evidence

At the time the following experiments were arranged (Toole, 1985, 1986), there were no omnidirectional loudspeakers of competitive sound quality that were available to me, so two versions of forward-firing loudspeakers were selected: a simple two-way of popular configuration, and a three-way, offering two distinctive off-axis behaviors. The highly regarded Quad ESL 63 represented the dipole category, even though it was not a perfect dipole because it attenuated the rear radiation at middle and high frequencies. — Toole, Floyd E, Sound reproduction- the acoustics and…, 434

Categorization

• XREF: connects to: Noncoincident resonances yield smoother speaker response than spherical shapes
• yield-rescued: below the book’s yield-target cutoff, included anyway for connecting to: Noncoincident resonances yield smoother speaker response than spherical shapes