ICBM LFE mix control & Sub level control

Okay I have read the manual several times now (had to be sure since I have had several beers )and I still honestly don't see what the LFE mix control does that the Sub level control can't do , or what the LFE control on a receiver/preamp (for those that have the ability) can do as well. Whew that was a ridiculously long sentence

Okay someone please enlighrten me!!

The LFE mix control adjusts the level of the ".1" channel only. The ".1" channel is typically used as a separate bass channel for music and movie soundtracks. However, the sub level control will adjust the output level of both the ".1" channel as well as the summed bass information from all of the other channels (center, mains and surrounds). Contrary to the belief of most enthusiasts the ".1" channel in DVD-Audio soundtracks is actually capable of a 20,000 Hz signal (though most tracks never go higher than 200 Hz).

Okay that makes sense now. I must have overlooked or not really understood that "summed bass" included any other bass being redirected to the .1 channel. It also explains you instruction manuals depth about those 2 adjustments a little.

Thanks!