I bought 2 of these from a shop not غ but feel like adding my voice.
My stereo system is high end in a 6x5m room, the subs also form part of my 7.2.4 setup.
These subs are wonderful, nicer bass response (not depth) than SVS PB16 Ultra subs (heard both with same speakers).
Bass is tight and musical, the PB16 Ultras had ringing that doesnt lend itself quite so well to music imo.
They are very powerful, mine are turned down a lot and give an astonishing performance with movies and music, never getting near stressed. They will go way louder than I can stand and well beyond 20Hz depth.
The EQ and other features work very well.
While they bedded in, the resonant freq was quite high up (over 50Hz) which dropped as time in use passed.
The EQ was very useful taming this, and matching them to my speakers.
Now they resonate near 20Hz after a year which I no longer EQ, I expect this to drop further.
If you are after a powerful, musical sub that can be optimally tuned to your room and system, this can do both without room treatments.
Highly recommended.