Alex, as Ken indicated, LFE is a specific channel(the .1, containing very low bass frequencies, almost entirely under 80Hz)that is present on occasion in 5.1(or 6.1)movie sources for handling extra-loud bass effects. Even there the LFE channel often has nothing in it when the movie doesn't have low frequency effects going on. Bass is a range of frequencies(typically defined as 20-200Hz)which can be present to varying degrees in all sound sources.

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Enjoy the music, not the equipment.