Hawkson, I think you'll find this article on crossover ranges very interesting. Without prescribing what everyone SHOULD do, it makes a good case for the benefits of using a high-pass crossover, even if you have large bass capable mains. Before reading the article I thought this was a silly idea (despite some good people advocating it on this forum) but I've since tried it and like it.
Another article Florian wrote on the
LFE Channel, explaining its history and technical background, is also pretty illuminating, though it's more in the way of background and does not directly address your crossover question. Both of these articles made me feel better about the irritatingly high fixed crossover (90 Hz) on my four-year-old Yamaha receiver. I could explain why, but you're better off reading his complete explanation, which goes into the technical details of "large" and "small" speaker settings, the rationale behind Dolby's numbers, and why you are not necessarily wasting the full range of your floorstanders if you set them to small or use a relatively high crossover. I experimented this morning with his ideas on my M60s and have to admit that set to "small" with my fixed 90 Hz crossover in action (which I would set to 80 if I had a variable LFE on the receiver), the M60s sounded cleaner, more open and accurate on Yo-Yo Ma playing Haydn than in my previous settings -- which include trying the passage with no sub. I'll try some films tonight after work. Before reading the article I was trying the "both" setting for bass management, but was not satisfied, because short of setting the crossover ridiculously low around 40 Hz or so I was getting overlapping bass between the M60s and my STF-2. Now I'm trying a sub-only bass management setting with the mains set to small.
Enjoyed your question, and please continue to "yap" away regardless of Chesseroo's ill humors (which I also enjoy ... who wants a forum of only bland people without opinions?).
