I just re-read my post and I don't think I typed what I was trying to say. For 99% of music on M60s you will never miss the sub. There are a few tracks like On The Run (Pink Floyd) where there are LF effects more like what you would expect in a movie -- no surprise there. Didn't notice a need for a sub on any other Floyd tracks, but oddly enough there were some things going on in the low bass on Supertramp tracks where having the sub did seem to make a tiny difference.
Overall, though, I am in complete agreement with Denver... for music M60s on their own are perfectly fine. I was surprised to find even a few cases where the sub made a difference and tried to report them for "completeness"
JB
