I've recently purchased an Onkyo NR3009 and am quite happy with the results. However, I don't understand the function of the LPF of LFE function. The manual suggests that it specifies the cutoff frequency of the LFE's channel's low pass filter, but what does this mean in actual practice? I've turned off the filter on my Velodyne CHT15 sub and all my speakers are set with a crossover of 80hz. The manual suggests that I should set the amp's LPF to 80hz, but I'm concerned that the dedicated LFE channel in 5.1 soundtracks will be adversely affected (ie. frequencies above 80hz will not reach the sub).