i tihnk they are about the same in sq and spl. I personally like the idmax's over the w6's because they are overpriced, and the idmax's sound so good. I tihnk the idmax is more power hungry, and i think the idmax would have higher spl
These are both great subs you cant go wrong with either one.They are in different classes. I am assuming you are talking about the w6v2 not the origanal w6 so that is what i am gonna go on. The w6v2 handles 400 watts rms while the ID max handles 1000. The price between the two is very similar. The ID max is a sub when put in a sealed small enclosure will give you incredible SQ with decent SPl but when in a ported tuned low enclosure will give some authorative SPL with incredible SQ. Now te W6v2 is geared toward SQL, I know there was an article in car stereo review or some magazine like that but I have a feeling JL threw up some serious coin to get that review. I am a big fan of the w6 it sounds great and gets loud also but I dont know about the best sounding woofer in production. The ID max in my opinion had it all over the w6v2 with similar SPL.
I had originally planned to get an AB amp (Zapco Reference 1100.1, 800W RMS @ 4 ohm mono) when I ordered the sub, but I got the JL from the shop I was at for free. Anyway, it is best to run a higher impedance on amplifiers due to the increased damping, S/N, lower THD, and also a less strained power supply for more headroom.