The one w7 install the I have heard was in a SQ competition car. it was in about a 1ft cubed box, sealed. the front stage was all custom out of parts express book. I think the dayton 3 way crossover and different tweets mids and woofers. rear fill was a set of alpine type r components. all were powered by various soundstream amps.
It was incredible. the sup in no way overpowered anything, and response was right on que, and very accurate. sound reproduction was right as it was recorded.
the w7 reproduced everthing that was sent to it, and with great detail.
I have no complaints, and any woofer that is in the same range as this is a truely worthwhile speaker..