m22ti with sub. what do i sent the crossover at on the sub. also what is the phase for? if i have the sub behind the speakers should it always be at 0?

Duff, you didn't describe your amp and sub. If the amp is multi-channel and has a crossover between the sub and mains at about 80-90hz, that's all the crossover needed; the sub crossover should be set to by-pass(if available) or turned up to the max to get it out of the way of the amp crossover. If not, then the M22s will run full-range and the sub crossover has to be used to fill in the M22 bass below about 70-80hz. It's not possible to say what setting, especially on an unknown sub, will do this, particularly since the markings on the sub crossover often aren't very accurate. Experiment.

The sub should be right in the corner closest to the speakers and in that location phase should probably be set at 0, but again, experiment to see if a different setting gives better bass.

SO WHY IS IT THAT THE m22I OR ALL OTHER BOOKSHELVES THAT ARE NOT BUILD TO HANDLE LOW FREQUENCIES BUT RATHER MIDRANHGES DON'T HAVE THEIR OWN CROSSOVER "BASS BLOCK" FOR PROTECTION, LETS SAY "CUT OFF" AT 75-80HZ?

THIS BOTHERS ME SINCE I CAN NOT TRUST THE AMP ADJUTMENT FOR LOW PASS AT 80HZ SINCE SOMETIMES WHEN THERE IS A POWER FAILURE, IT RESETS ITSELF. IF I RUN FULL AT HIGH VOL AN ACTION MOVIE, THIS CAN BE RISKY, ISN'T IT?

i HAVE A PIONEER ELITE THX AMP, RATED AT 150 W/RMS PER CHANNEL.CAN THE M22I HANDLE IT?

THANKS FOR YOUR REPLY.
DJ

DJ, it isn't a matter of "protection" ; it's how to get the best sound out of the combination of sub and main speaker. There's no danger in these smaller speakers being run full-range(as they have to if there isn't a sub)it's just that the sub should be able to handle the frequencies under about 100hz better and should do most of the work there.

It doesn't matter how much power an amp can supply; a speaker will only draw as much power as it needs at that instant. Therefore a speaker doesn't "handle" the full power that an amp is rated at.

You know there is one thing that a lot of people overlook/ or do not realize. Running full range to all the speakers requires your amp to work a lot harder then if you have the speakers set to small and let the amp in the sub do the work. On lower end amps the results can be very dramitic as the unit will run much cooler and cleaner without running out of headroom as quickly as it will with the speakers set to large. Low frequencies require a lot more power to produce then do the mid and high range frequencies.