Figuring out what useful data is and is not is a major challenge. I don't want to post a ton of graphs just for the sake of it.
Covered a lot in the spinorama, but:
•
Sensitivity / Impedance / Phase
•
On-axis
• Usually tweeter access, but read manual or look at vertical performance; one pet peeve with Stereophile is J.A. will state the reference axis is below tweeter level, but will have tweeter level as on-axis, making performance seem poor (
example).
•
Listening window (debatable on angles; usually +/-15° H with +/-5° V)
•
H/V off-axis plot; I prefer both an off-set 3D view (Stereophile) as well as 2D (Audioholics)
• Usually referenced to on-axis, but if on-axis is sacrificed for overall sound (Gedees), show non-referenced, Stereophile sometimes does this.
• As for angles, +/-90°?
•
H/V polar plots; less telling version of off-axis plots, but are easier to read.
•
THD (maybe @ 95dB @ 1m, but 105dB is reference level peaks, but not all speakers can handle this, the NRC does 96dB and 101dB if the speaker can handle it).
•
CSD/Waterfall (normalized)
• Predicted In-Room Response
• Cabinet resonances (can be indirectly seen in FR measurements, but a direct test like Stereophile’s would be appreciated).
• Linearity (compression), usually not a big deal, but should be run and shown if not great, NRC does 76dB vs 96dB and goes louder if the speaker can handle it.
• Max SPL @ given THD, Neumann shows this for their speakers (1%, with 10% for bass), not a necessary graph.
_________________________________________________________________
Measurement site comparisons:
KEF LS50:
Stereophile vs
NRC
Revel M126Be:
Audioholics vs
NRC
Neumann KH80:
Sound & Recording (German)