Chess, of course my comments were based on a situation where the sub was of superior quality(such as the EP800)and was placed for best reproducing the low bass frequencies. If these conditions don't prevail because the sub and/or its placement aren't adequate, and the speakers do a better job, then the sub shouldn't be given more of the bass range and maybe shouldn't be used at all. In my view, based on principles of bass reproduction and to some extent my personal experience, in the great majority of cases using good subs properly positioned they should be handling most of the low bass frequencies and the mains should be rolled off electronically. So, this will continue to be my general suggestion.
In your case, where you're not using a crossover on the M60s, it's entirely likely that setting the low-pass filter(not "crossover")on the EP350 to 45-50Hz may give the best blend with the "natural" roll-off of the mains. It wouldn't be surprising that setting the sub higher in that situation would result in the sound being "too heavy and bloated" with both the sub and speakers playing full-strength. Minimizing that is why both sub and speakers should be rolled off electronically and not be simultaneously playing full-range.
