Hi Nickwh,
The crossover frequency used in the M22ti is 3.5 kHz. The M40's crossover frequency is 2.2 kHz. It's not so much that the crossover frequencies are "missing" from our specs; it's that the designer believes (and I heartily concur) that while it may be technically interesting, unless you are an engineer, knowing the crossover frequencies is not information on which to base an informed judgment of loudspeaker accuracy or quality.
Overload protection is a function of the output circuitry used in an amplifier or receiver. It's not a factor in loudspeaker design. It is not possible to effectively fuse loudspeakers to protect against transient overload, clipping, and other electrical abuse.
The surround material is a rubber composite.
Regards,
