Solid bass, great excursion, plays low frequencies. Good for sound quality. Requires relatively small box for sealed enclosure.

Not an SPL subwoofer. Small surface of the cone (again not for spl). Hard to find (for pairing).

I bought this subwoofer for SQ purposes. I love it! Very fast response, very clean tight bass. I use it in an 1.75 cu/ft selaed enclosure. In this box the subwoofer behaves very dynamically. It reproduces very low sounds even for closed box. Still it is not that loud in the lower frequencies (30Hz) as a 15" sub, but it is pretty close to it. Has an tremendous excursion in sealed box. As far as frequencies i can say that reproduces very well the frequencies between 40 and 60-70Hz. On a SPL contest hit 130 db in that sealed enclosure in a sedan.