[Electrodynamic]

The new XXX's are more inefficient than the older XXX's. When I say "inefficient" I mean actual output out of a specified size and type of enclosure with actual power, not the 1W/1M figure. We have a paper on subwoofer efficiency hosted on our technical web page that you should read through if you haven't done already. The older XXX's are considerably less expensive and they're not as deep as the current XXX's.

For what it's worth: the MTX 9500's are one of the most inefficient drivers I've ever been witness to. You have to POUR on the power to get them to put up anything decent on the meter. And even then, odd are...you'll probably blow them in the process.

But anyway, four Mag's with 2k watts or more should be able to do in the mid 140's. That's all I'm going to say because there are a [i]lot[/b] of variables to consider in an SPL setup, and most of them you can't anticipate unless you have thorough experience with that exact vehicle.