Excessive rear-wall diffusion can destroy the stereo center image

Evidence

The problem: too much uncorrelated sound arriving from behind the listener, scrambling the information in the direct sound from the loudspeakers. Lesson: there can be too much of a good thing. The ETC probably looked just fine, though. Somebody measured but did not listen. — , Toole, Floyd E - Sound reproduction-…, 702 (#corroborates, via linked claim)

The effect of this is a large reduction of the comb filtering effects that highlevel early reflections cause. This is due to both the reduction in amplitude due to the diffusion and the smoothing of the comb filtering caused by the multiplicity of time delays present in the sound arriving from the diffuser. As these comb filtering effects are thought to be responsible for perturbations of the stereo image (Rodgers, 1981), one should expect improved performance even if the level of the early reflections is slightly higher than the ideal. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2309 (#qualifies, via linked claim)

Categorization

• XREF: connects to: Center channel carries most dialog but stereo mixing habits undermine TV use; Excess uncorrelated rear-wall sound can destroy the phantom center image — , Toole, Floyd E - Sound reproduction-…, 702; Diffuse reflections reduce comb-filtering that perturbs stereo imaging — David Howard, Jamie Angus, coustics and Psychoacoustics, 2309

Broader Connections

• Excess uncorrelated rear-wall sound can destroy the phantom center image #corroborates (1.00) — , Toole, Floyd E - Sound reproduction-…, 702
• Diffuse reflections reduce comb-filtering that perturbs stereo imaging #qualifies (0.80) — David Howard, Jamie Angus, coustics and Psychoacoustics, 2309