Okay, about the measured distortion responses that I asked you guys for comments on: See them again below.
Thank you, to all that were willing comment on it. Who was willing to respond and who was not spoke volumes! Even those that did comment on them had different impressions and this further illustrates that perceptions can vary. This will also illustrate that you can't get the whole picture from just one set of measurements.
Most here all agree that distortion measurements taken at different locations and in different manors should not be compared to one another. However many feel that measurements taken from the same system and in the same way are good for comparing to one another. Funny thing is that most of those people were afraid to make any subjective assessments on the data posted here when two woofers were measured in the same way, on the same system, and in the same room.
Dan Wiggins and I both posted data showing response variations (near field anomalies) in near field measurements that will effect any distortion measurements.
It was then stated by Mark K on page 19 that "the distortion measurements that John and I do are not done nearfield".
I mentioned in the first page of this thread issues regarding distortion measurements made in room, and how it can be effected by room noise. I also sighted information regarding this from the Clio manual. Measured distortion levels are at levels that are near or below room noise levels and separating them from room noise is not possible. Output levels can be increased so that room noise is a smaller percentage of the output signal but it cannot be removed from it. Getting closer to the woofer can also increase output levels in relation to room noise levels but again the room noise levels cannot be removed from the measurement. Then if you get too close you get an inaccurate response.
The measurements posted again below, made from 1 meter away, shows that room noise will make measurements inconsistent and that several must be taken to see a range.
We must also keep in mind that distortion levels created by a woofer at low power levels are not going to be the same as distortion levels taken at high power levels or when a woofer is driven hard.
Now lets look at the measurements made and posted below.
Here are second order harmonics:


Here are third order harmonics:


Here are 4th order harmonics:


And here are 5th order harmonics:


Woofer number one was of coarse not just the measured distortion (2nd, 3rd, 4th and 5th harmonics) of the woofer itself but also of ambient room noise. The greatest level of room noise came from the only thing "on" in the room, the measuring computer. One thing to the favor of the woofer being tested though, is that it is a directional microphone and the computer was about 120 degrees to the back side of the microphone and about 1 meter away.
Woofer number one (Red, Orange, Yellow lines) was an M-130 in a standard A/V-1 box.
Woofer number two (Green, Blue, Purple lines) was actually not a woofer at all. For these measurements the woofer was disconnected and the microphone was rotated towards the measuring computer and the only thing it picked up was ambient room noise and the noise from the computer fan.
Now, can we really tell how good or bad a woofer will sound from distortion measurements taken this way? Just image the effect an air conditioning system will make if it came on during the tested of one woofer and not another.