I am using a Sunfire Signature subwoofer with my Magnepan 3.5/R.You can get spectacular results if this sub is moved away from room boundaries (certainly not in a corner as recommended by Bob Carver) and if the volume is kept at a sufficiently low level so that the sub is audible only with bass material below about 50 Hz (if x-over is set at 30 Hz) and with the proper use of the phase adjustment . My Signature disappears completely in my system. The blend is seamless and the result is very musical. I tried the RELs, but they were too difficult to set up because the Phase adjustment was only 0/180, whereas the phase of the Sunfire can be adjusted continuously from 0 to 180. In the case of the RELs you had to move them until the "correct' location is determined. I think the Sunfire Signatures have received a bad rap from users who have not set them up properly. I get clean extension to about 16 Hz with air, power and definition.
