Use the MPS 150 powered subwoofer in the LFE or subwoofer out channel. Some only go to 80 Hz and that is not high enough to meet the satellite. This way you have full range front channel speakers with only the satellites showing. You thus insure proper integration of the satellites into any system regardless of the subwoofer chosen. You also gain the ability to listen to high quality two channel music by switching off the surround processing.
Most systems offer only the powered sub and they almost never sound right for music.
Powered subs in general are more sound effects generators then musical transducers. New digital formats have the ability to send full range signal to all channels. You can use the passive sub to augment the rear channels and even run in mono with two satellites as a full range center channel. Best of all, the modular design allows you to add on at any time. S2 dramatically increases the output of the system.