Excel W12 lower distortion than W15?!?

[capslock]

As this has not drawn any responses in the madisound forum, I am reposting here:

These two beauties seem to share the same motor, except that the W15 has a longer voice coil. I suspect the cones are the same, except for the diameter at which they were cut off, because the peaks at 7 and 10 kHz look very similar (actually, the 7 kHz peak is less pronounced in the bigger W15).

Knowing this, I would suspect the W15 to have better distortion performance because of its 50% higher cone area and greater linear travel. According to the published data sheets, the distortion increase below 200 Hz is indeed lower, although still high enough to warrant a separate sub.

Strangely, between 200 and 600 Hz, the smaller W12 definitely has an edge. In this range, distortion should still be dominated by excursion, Le variation and cone flexing kicking in a little higher. Then from 600 Hz to 2.5 kHz they are virtually identical.

Measurements of the W15 in HobbyHifi and the W12 in Klang & Ton seem to confirm this trend that the W12 is acutally the lower distortion device, but then results between these magazines even for the same driver model agree often but not always.

Anybody have a guess or better even measurements to clarify if this is real?

Regards,

Eric