Of course the Sumiko/SF people would recommend REL. Sumiko distributes REL as well. Cremona Ms are extended and flat right down to 40 Hz and drop off pretty sharply after that. So for most music they sound just fine, but if you listen to orchestral or prog rock driven by a 5-string bass or synth or pipe organ, getting full measure of that last octave would be a good thing.
I don't know what your budget is, but did you know that Sonus Faber makes their own powered sub in the Cremona line? Not cheap, but should be well-suited for integrating with the Cremona Ms.
Also, if you want the sure bet for the sub that integrates, that can match power output, speed, and bass extension to your speakers, it's JL.
Other contenders would be the better offerings from Martin Logan and B&W (their PV1D is really impressive).
I don't know what your budget is, but did you know that Sonus Faber makes their own powered sub in the Cremona line? Not cheap, but should be well-suited for integrating with the Cremona Ms.
Also, if you want the sure bet for the sub that integrates, that can match power output, speed, and bass extension to your speakers, it's JL.
Other contenders would be the better offerings from Martin Logan and B&W (their PV1D is really impressive).