Comparative measurements remain reliable even without absolute low-frequency accuracy

Evidence

This chamber was not perfectly anechoic at the lowest frequencies and, although it had been calibrated for the measurement of loudspeakers in isolation, the presence of the massive wall structure introduced errors. Consequently, no claim is made for absolute accuracy at low frequencies in the measurements that follow, but they should be reliable in a comparative sense. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1477

Categorization

• QUESTION: How much does a non-perfectly-anechoic chamber and a wall structure compromise low-frequency absolute accuracy, and what magnitude of error is considered acceptable?
• XREF: connects to: Long scales achieve acceptable reliability without valid unidimensional measurement; Controlled measurements confirm the theoretical boundary-gain relationships at low frequencies — Toole, Floyd E, Sound reproduction- the acoustics and…, 1458; A just-noticeable difference in signal-to-noise ratio does not guarantee subjective value — Dijk, Pim van, Physiology, Psychoacoustics and…, 5669 (+2 more)
• yield-rescued: below the book’s yield-target cutoff, included anyway for connecting to: Long scales achieve acceptable reliability without valid unidimensional measurement; Controlled measurements confirm the theoretical boundary-gain relationships at low frequencies — Toole, Floyd E, Sound reproduction- the acoustics and…, 1458; A just-noticeable difference in signal-to-noise ratio does not guarantee subjective value — Dijk, Pim van, Physiology, Psychoacoustics and…, 5669 (+2 more)

Broader Connections

• Controlled measurements confirm the theoretical boundary-gain relationships at low frequencies #complicates (0.71) — Toole, Floyd E, Sound reproduction- the acoustics and…, 1458
• Test fixture fidelity to human measurements remains an open question #complicates (0.71) — Toole, Floyd E, Sound reproduction- the acoustics and…, 1710