What we know about the measurement:
SunAudio Purified 4 4XA25B Alu+Berryllium is a passive bookshelves that cost around 3650 USD for a pair.
 Quality of the measurement data is high.
 Origin of the data is SunAudio.
 Format of the data is a set of 36 horizontal and 36 vertical measurements .

Sensitivity:
 Sensitivity: 85.6dB (avg. 100Hz1kHz for 2.83V estimated at 1m).
 Sensitivity: 77.6dB computed at the measurement distance (2.5m) over the same frequency range.
 3dB (resp. 6db) point v.s. reference is at 70.3Hz (resp. 61.7Hz).
 Reference level is normalised to 0.1dB computed over the frequency range [300.0Hz, 5000.0Hz].
 Frequency deviation is 1.3dB over the same frequency range.
 Directivity
 Horizontal directivity is (80.0°, 80.0°) between 1kHz and 10kHz. Angle computed for +/6dB.
 Vertical directivity is (30.0°, 10.0°) between 1kHz and 10kHz. Angle computed for +/6dB.
 Tonality (Preference) Score
 Tonality (Preference) Score is 6.66
and would be 9.37 with a
perfect subwoofer.
 Details: NBD: ON 0.127, LW 0.078, SP 0.12, PIR 0.087; SM: SP0.979, PIR0.978; LFQ 0.489, LFX 61Hz
 Tonality (Preference) Score is 6.66
and would be 9.37 with a
perfect subwoofer.
 Link to Original review.
 Note: Crossover Woofer: BW12 @ 2158Hz Tweeter: BW12 @ 4146Hz. Measurements done at 2.5 meter..