Here are two graphs. One taken with the raw driver on the chair as seen above, the other in the small sealed box (leaky seal).
WE FR boxed
WE FR raw

Normally I don't show such an expanded amplitude scale, but here it was done to show the low distortion of the driver. 3rd harmonic is shown, but the others are in line with this, dropping off naturally from 2nd thru 7th. A very clean driver.

Darn good for a 12" full range! Yes, it beams, but it's a 12" with no whizzer. Notice no bad cone breakup, either. I see F3 as about 53Hz in that box. Don't know the impedance, but DCR is 3 ohms.
We used a mono 6L6 P-P valve amp for all the tests.

One thing A.A. didn't mention is how damn heavy this thing is. A beast!