Actually Legairre, in absence of the surround speaker with full range capability, the main LFE channel picks up the extra material encoded to the surrounds if they are set to 'small' in the receiver.
In effect, you ARE already hearing the surround LFE with only the .1 setup. I very much believe alot of ppl see their sub at the front of the room and think "hmm, shouldn't there be LFE sound in the rear too?" and then this idea gets started. But of course, the way the small speaker settings direct LFE, it should be a moot concept.
As before, location should not matter for LFE unless there is a room interaction or the LFE sound is mixed across more than just the single channel (highly likely for any explosion type sound) thus adding 2 subs to sound volume instead of just one.
In regards to the DPLII observation, i've found that the surrounds play rather oddly depending on the recording. When i was testing out sub vs sub, i unplugged all other speakers to do an A/B switching b/w sub units, however i wanted to use the same music passage for each unit. The problem was with only the LFE playing, i didn't know what part of the music i was hearing, so to compensate i plugged in a single surround channel so i could follow some of the vocals to the point i wanted to compare. I turned down the gain in the receiver on the surround channel quite low (like -10dB) so it would not overly interfere with my subwoofer listening. It was during this test that i realized the surround sound was literaly cutting in and out during the song. It was an odd effect to hear and not one that i expected.
Since then i've had some doubts about how effective the DPLII is for music. I've personally never found it to be particularly convincing and certainly no where near the quality of a DVDA mix as surround sounds go.
