They are of the same quality as the current Pyle, Legacy, Boss, etc.....
I have constructed 3 different enclosures for 3 different lines of Volfenag. All have gotten loud, which is not too difficult with pretty much any sub and a decent enclosure. The SQ was decent at best. Also note that each one of these subsystems were all powered by a Volfenhag amplifier as well, which was well, about as good as a hairdryer. It sounded similar to one as well.
IMO, there's much better available for the money. People can look through the chrome and flashy BS cosmetics and know right offhand whether they are making a wise investment on many products. This is one of them.
If they were given to me, they would be instantly plugged into a 240V socket and dismantled for scrap.