Depending on your application/trunk space, those W7s will give you excellent SQ and SPL. I doubt you have trunk space for 2 of those suckers. Have you listen to ONE in a HO box? You might not even need 2 of them. One will pound the crap out of your ear drums and your chest. However, it's not like the pounding you get from RE MT sub. More like a sledge hammer vs very heavy hammer. I remember my experience with W7 and MT on the same day. MT gave you ear ache as well as body massage. W7 didn't pound your chest as hard, but it sure made my ear drums ache. Not from the heavy thumping, but from very LOW bass that never seem to end.
Well for now, I will make a sealed enclosure for the 12W7 and use the HO box later when I get a car with more trunk space. The MT with W7 gives you one of the best sounding bass. W7 will cover the ultra lows and MT adding thunderous thumping power. The problem I had was, at low - mid volume, MT can't produce the kind of bass I was looking for. With these 2 combo, it sounds great.
No. MT will give you window pounding bass. JL will give you very low bass that numbs your ear drums. Those put together will give you one heck of a combo. IsaacW, when newbies go straight into SQ, they tend to undervalue their products or get side tracked by SPL.