Just came across some spectra labs plots by Ikka in another thread. The movie is Flight of the Phoenix LFE channel (only took me 15 minutes to work out what FOTP was). There's some high spl 100hz stuff in there.
In the same thread the plot for War of the worlds shows that theres not much over 70hz in the LFE, all the higher bass frequencies are in the full range channels.
It looks like the upper limit of the LFE is dependant on the mix, when I watched Flight of the Phoenix I do remember having to dive for the remote in the barrel roll scene because the bass was unbearable, looking at the plot the red 100hz stuff lines up with one of my 12 db peaks. This movie might be an exception though as I have not had to do that with any others, although I could hear a difference when switching presets while watching the AVS LFE demo the other night.
I would like to see more of these plots but can't find them online.
edit: just found some more, LOTR LFE only
Titan AE LFE only
Chris, I changed from an 80hz xover to 100hz and it really helped out with the integration between mains and subs, it smoothed out some peaks that were caused by the sum of the mains and sub. It might be worth trying some different xovers if your AVR will do that.
Those full range sweeps are pretty painful at the top end, I'm gonna get some earplugs for my next session.
Hakka.