I wouldn't know about their other speakers, but I've owned a pair of their 1723 range sealed subs for a couple of years and I really like them. They reach 20 maybe 19 Hz quite confidently in my room, you need to drive them really hard until they start to distort and I'm very pleased for their sound quality. They play music very well and movies too, although if you need sub-sonic rattle, try the ported versions, and if you need wall-shattering infras, maybe look for something bigger. Quite surprisingly, they are still the weakest part in my otherwise DIY set and subject for the next upgrade if I suddenly need to remove windows without touching (sarcasm aside, I have no need for such upgrade)
