I am curious how many people are running their speakers with the 40hz crossover. I have a pair of vintage Infinity kappa 7 speakers as my L&R fronts, which have a -3db point of 37hz. I have been using the 60hz crossover with these, but at that setting the 12" woofer barely gets worked. So, I have been messing around with the 40hz setting and so far, the only times I have gotten a little nervous is with LinkinPark dvd audio, and Live Free Die Hard on blu ray.
What are the chances that the replacement for the 990 would include a 50hz crossover point.
Are there others in the same boat, or do most have smaller speakers? Suggestions and opinions welcome. Thanks, Brian

I would run them at least at 60Hz. Since the 3dB down point is very near 40Hz, the slope of the crossover will contain too much of the speaker's natural rolloff if you use 40Hz as a crossover point.

With a -3dB point of 37Hz, I'd also lean toward 60Hz crossover. I used 40Hz with my Paradigm Studio 60's at one time (which have a -3dB point of somewhere in the 30's) because my SVS 25-31PCi sub got a bit boomy on music when using the 60Hz setting, but I moved to 60Hz after swapping out the sub for an original LFM-1 and preferred that setting.

Interesting question about the 990's replacement and additional crossover settings. It's certainly a possibility...