Just to clarify for folks, there are different settings with different labels. Call them by the proper terms and you minimize the confusion.
A) avr's LPF of LFE. This is the Low Pass Filter cutoff for the Low Frequency Effects channel. It ONLY affects the .1 LFE channel. Since the specs for the LFE channel include content up to 120Hz, this is what it should be set to to avoid cutting out content in movies. This setting has NO effect on bass managed content. That's determined by the crossover.
B) Crossover settings. In most modern avr's and pre-pros, there is only a speaker crossover setting. Setting this to any setting/frequency (other than Large/Full Range) automatically sets the High Pass Filter for the speaker AND the Low Pass to the subwoofer. This setting can be varied depending on the speaker's low frequency capability, but shouldn't be set lower than double the speaker's F3 (i.e. if the speaker's -3db point is 30Hz, the XO shouldn't be set lower than 60Hz).
C) subwoofer LPF. The Triax doesn't have this, but on subs that do, when using crossovers (i.e. in the avr or pre-pro) and EQ, this should be set to the highest setting possible to avoid doubling the rolloff due to doubling filters (i.e. setting the sub's own LPF to 120Hz AND the avr's XO to 120Hz will result in a steeper rolloff).
So keep the avr LPF, XO and sub LPF terminology separate and you minimize the confusion.