I agree completely with the comment on HT vs. music. At one point yesterday when I was testing out my new axioms, I changed over to stereo and shut off the sub. (So I was just listening to the m60s.) I listened for a while, then, forgetting that I had shut off the sub switched back over to PLII. The music still sounded excellent, I didn't even notice that the reciever still had the sub set to "off". The upper bass and lower midrange that the m60s produce is very clean and alive. You can close your eyes and imagine you're sitting right next to instrument itself. If you have any halfway decent recordings with an upright bass or cello, you probably know what I mean. (Granted had I been listening to dance music of some sort I probably would have noticed the missing sub.)
So, after a half an hour or so I put in "Fellowship of the Ring", I like the initial scene where Sauron essentially explodes and the shock wave goes out across the battlefield to test low bass, and I wanted to get my sub set in balance with the axioms. Now, with a powerful sub, you can seriously feel the shockwave pass over you, and I felt nothing. Which is when I finally realized I hadn't turned my sub back on.
Point being, for music the m60s sound excellent across the spectrum. But when it comes to groundshaking, you will want a sub.
-A
