Single-axis measurements misrepresent multidirectional loudspeakers like Bose

Evidence

Notably absent from this collection is the Quad ESL 63, but some data are shown in Figure 4.7. Also absent from the displayed products are those from Bose. To reveal useful performance data on their multidirectionally radiating loudspeakers requires the digital measurement system that can perform spatial averaging and a sound power calculation; it did not exist at the time I was doing those tests. Measurements on single axes show acoustical interference that is disturbing to the eye but not necessarily evident to listeners in normally reflective rooms. So, rather than show misleading data, I show none. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1946

Categorization

• XREF: Echoes the book’s earlier argument that broadband/spatially-averaged measurements are needed for omnidirectional designs; connects to reader’s notes on measurement methodology in psychoacoustics. — connects to: On-axis curves alone cannot predict loudspeaker sound quality; Highly regarded loudspeakers measured far from flat in anechoic response; On-axis response alone cannot predict how a loudspeaker sounds in a room (+1 more)
• corroborated: 2 independent passages support this claim — Toole, Floyd E, Sound reproduction- the acoustics and…, 1946

Broader Connections

• On-axis response alone cannot predict how a loudspeaker sounds in a room #corroborates (0.90)
• Highly regarded loudspeakers measured far from flat in anechoic response #exemplifies (0.85)
• Anechoic on-axis and sound power responses suffice to predict perceived loudspeaker quality #contradicts (0.80) — , Toole, Floyd E - Sound reproduction-…, 1292