I love my W7. The second best sq ('sql') subwoofer I have heard to this date. Of cource, it needs a bit more power then most other woofers, but I can live with that. I'm now feeding it 530w, and that's more then enough for my needs.
I also like the Soundstream SPL12, it's one of the loudest, cheapest and least powerhungry woofers I have ever had In my car. It'll make you deaf with only 150w per coil, great value.
I heard a IA ND-12 once, and all I have to say is
If you know a place I can buy one, tell me
