More playback channels increasingly mask audible loudspeaker resonances

Evidence

In Sections 4.4 and 4.5 it was shown that from the point of view of sound quality, the most challenging listening tests for loudspeakers were those done in mono. People heard and complained about resonances in loudspeakers. Adding a single channel for stereo made listeners less responsive to flaws in loudspeakers, as persuasively shown in Section 4.4. Adding more channels in multichannel made them even more forgiving (Figure 5.7(b)). Simple logic suggests that the complexity of the sound field in the room was responsible. The ray diagrams in Figure 5.12 are persuasive evidence of that. But, if the resonances were in all the loudspeakers, why would having more of them playing simultaneously make the resonances less audible? — Toole, Floyd E, Sound reproduction- the acoustics and…, 568

A major purpose of these tests was to compare subjective rating performances when listening in mono, stereo and 5-channel multichannel modes. Figure 5.7 shows the result, and it is very clear that adding more active channels to a listening experience reduces one’s ability to discern details of loudspeaker performance—but the least flawed loudspeaker (the anechoically equalized version) was recognized in all playback modes, albeit with statistical significance only in mono mode. — Toole, Floyd E, Sound reproduction- the acoustics and…, 520

Categorization

• QUESTION: Toole poses the mechanism question himself — why does more simultaneous resonance sources reduce audibility? Worth chasing the explanation later.
• XREF: Links to the reader’s stated goal of understanding how physical stimuli cause perceptual responses; this is a core masking phenomenon. — connects to: High-Q resonances are rarely heard but catastrophically audible when music hits their exact frequency; Stereo and multichannel listening make listeners more forgiving of loudspeaker flaws — Toole, Floyd E, Sound reproduction- the acoustics and…, 467; Recorded venue acoustics masked loudspeaker resonances that technical signals reveal (+5 more)
• corroborated: 3 independent passages support this claim — Toole, Floyd E, Sound reproduction- the acoustics and…, 568; Toole, Floyd E, Sound reproduction- the acoustics and…, 520

Broader Connections

• Recorded venue acoustics masked loudspeaker resonances that technical signals reveal #corroborates (0.85)
• Room resonance excess masks loudspeaker bass deficiency to listeners #corroborates (0.82) — Toole, Floyd E, Sound reproduction- the acoustics and…, 549
• Masking acts within critical bandwidths, leaving distant-frequency sounds unaffected #qualifies (0.80) — Eric J. Heller, Why You Hear What You Hear- An…, 2009
• The listening room’s influence is suppressed during multichannel playback #expands (0.75)