Everyone is an expert critic.
And I'm sure this is equivalent to Soundstage's NRC, Stereophile, Home Theater Magazine, and Sound & Vision Magazine, right?
Even if it were measured outdoors and all, how do we know everything was done correctly and reliably?
I don't think HSU would design such a poor subwoofer, even if it's only $279.
And you might also want to through in the part were Ricciophile wrote:
"The distortion performance was surprisingly good though, and it is a rugged unit with good overload characteristics. I wouldn’t recommend it for larger rooms or people that like to listen loudly, but a pair could probably do a decent job for most spaces."