Published spinorama measurements frequently violate standard resolution requirements and are then unreliable

Evidence

The website www.spinorama.org reveals links to spinorama measurements on hundreds of loudspeakers from many manufacturers and independent sources evaluated using the ANSI/CTA-2034-A (2015) standard method. In a few cases, it is impossible to learn much from the published spinorama data because the curves have been overly smoothed (a persistent marketing department practice) or lack adequate resolution at lower frequencies caused by the time-windowed FFT measurement method. Both violate the frequency-resolution requirements of the standard, and such data should not be trusted. — Toole, Floyd E, Sound reproduction- the acoustics and…, 227

Categorization

• DEFINE: Clarifies what the ANSI/CTA-2034-A standard requires of spinorama data: adequate frequency resolution, which smoothing and time-windowed FFT both undermine.
• XREF: Connects to the earlier chapter’s discussion of Klippel near-field scanning as the measurement method behind modern spinorama data.