Phantom center image sound quality is inherently compromised even in the sweet spot

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 (#expands, via linked claim)

The stereo phantom center image will suffer from a significant dip in the spectrum around 2 kHz because the sound from both loudspeakers reaches both ears at different times. This interaural crosstalk cancellation is the first dip in an acoustical interference comb filter as explained in Figure 4.4. — Toole, Floyd E, Sound reproduction- the acoustics and…, 415 (#corroborates, via linked claim)

It is a clearly audible effect. Plenge (1987) explains it, as done here, and goes on to relate it to some theories of timbre perception, pointing out along the way that most listeners do not sit still, and are obviously not bothered by the consequent changes in sound image location and timbre. However, dedicated audiophiles and recording engineers who gravitate to the stereo seat are exceptions. Augspurger (1990) describes how easy it is to hear the effect using 1/3-octave bands of pink noise, observing a “distinct null at 2 kHz” (p. 177). Pulkki (2001) confirmed that the comb filter was the dominant audible coloration in anechoic listening to amplitude-panned virtual images, but that it was lessened by room reflections. Listeners in experiments by Choisel and Wickelmaier (2007) reported a reduction in brightness when a mono center loudspeaker was replaced by a stereo phantom image (their figure 4). Listeners in the Shirley et al. (2007) experiments not only heard the dip seen in Figure 7.2e but demonstrated that it had a significant negative effect on speech intelligibility. This is hardly the epitome of sound reproduction technology. — , Toole, Floyd E - Sound reproduction-…, 673 (#expands, via linked claim)

Categorization

• XREF: connects to: Excess uncorrelated rear-wall sound can destroy the phantom center image — , Toole, Floyd E - Sound reproduction-…, 702; The stereo phantom center image suffers an audible 2kHz timbre dip affecting speech intelligibility — , Toole, Floyd E - Sound reproduction-…, 673; Phantom center images reduce speech intelligibility due to interaural crosstalk (+2 more)

Related

• Phantom center images reduce speech intelligibility due to interaural crosstalk (similarity 0.94)
• Stereo phantom center images have a spectrum dip near 2 kHz from interaural crosstalk (similarity 0.93)
• The stereo phantom center image suffers an audible 2kHz timbre dip affecting speech intelligibility (similarity 0.93)
• Headphones lack the phantom-center 2 kHz comb notch present in loudspeaker stereo (similarity 0.91)
• Excess uncorrelated rear-wall sound can destroy the phantom center image (similarity 0.89)
• Excessive rear-wall diffusion can destroy the stereo center image (similarity 0.87)
• A speaker near hard surfaces produces phantom image sources that color its sound (similarity 0.86)
• The phantom center image in stereo is always corrupted at the symmetrical sweet spot (similarity 0.85)
• Stereo phantom images timbrally differ from real-source or mono center images. (similarity 0.84)
• A real center speaker improves dialogue clarity over a phantom center (similarity 0.83)
• Listeners prefer familiar distorted phantom images over technically superior real center channels (similarity 0.82)
• Excessive center-channel upmixing damages music soundstage rendering (similarity 0.82)
• Center channel carries most dialog but stereo mixing habits undermine TV use (similarity 0.82)
• Phantom center dullness stems from destructive acoustical interference, not loudspeaker inadequacy (similarity 0.81)
• Wide-dispersion loudspeakers soften hard-panned images and reduce the center-image crosstalk dip (similarity 0.80)

Broader Connections

• Excess uncorrelated rear-wall sound can destroy the phantom center image #expands (0.85) — , Toole, Floyd E - Sound reproduction-…, 702
• The stereo phantom center image suffers an audible 2kHz timbre dip affecting speech intelligibility #expands (0.80) — , Toole, Floyd E - Sound reproduction-…, 673
• Stereo phantom center images have a spectrum dip near 2 kHz from interaural crosstalk #corroborates (0.80) — Toole, Floyd E, Sound reproduction- the acoustics and…, 415
• Phantom center images reduce speech intelligibility due to interaural crosstalk #expands (0.78)
• A speaker near hard surfaces produces phantom image sources that color its sound #exemplifies (0.72)