Perhaps, but conducting a test like that outside is nearly pointless.
And using those numbers to prove a point is downright silly.
Even the guy who tested later admits:
"No. In fact the lines on the graphs do actually continue below 23/24Hz. However, the THD graph starts to become unreliable when the fundamental frequency gets too close to the noise floor. So to keep things consistent, I truncate/shade the plots where the data starts to become unreliable. In fact the FR and Power Compression graphs are still pretty accurate down to the 60dB mark, the THD graph is a bit more sensitive.
Because we are measuring outdoors, there is an ever-present noise floor at or around 40dB. Wind noise, birds, trees, golfers cursing on the course next door, distant planes, Jerry's ice-cream van, AV Talk sub test spectators chatting, etc, etc. The precise spectral content of this varies over time but there is some noise ever-present at around this level."
Sorry, that's not a very smart way to test speakers.
Though, I did gain some amusement by Mike C's "they suck so bad I bought two of them" admission.