When a movie has an LFE channel, it knows the LFE will be +10 dB.
When Media Center builds an LFE channel, it knows the LFE will be +10 dB.
See how they're the same?
So to make sure your LFE really is +10 dB (not +8 dB, or 0 dB, or -20 dB, or whatever), you use the volume calibration method I described above.
Everything in Media Center understands that the LFE channel is at a different level, so it's not something you as a user ever need to worry about (other than setting levels one time). You can set levels using DSP Studio > Room Correction, or by adjusting a physical volume on your subwoofer, or any combination of the two.
Does that make sense?
I think some of the confusion, at least for me is the often used interchangeability of LFE and subwoofer.
If I understand things correctly from Matt:
1. A movie that is 5.1 encoded has an LFE channel that is 10 db down in volume.
2. MC does the following if the system has been calibrated per Matt's procedure in post #7 above:
A. For a 5.1 encoded movie MC will add 10 db to the
Subwoofer channel.
B. For a 2.0 movie MC will have JRSS build an LFE channel that will be routed to the subwoofer. It will have
10 DB boost applied by MC.
C. For 2.0 Music JRSS will convert it to 5.1 and the Subwoofer channel will have no boost.
D. For 5.1 encoded music there will be no boost applied to the subwoofer channel.
So Matt what you say makes sense. My difficulty is I have read in several places that a 10 db boost needs to be applied to the LFE channel besides anything MC does. mojave mentioned it in his suggestion to add 10 db in the 'mixing procedure' and hulkss mentioned that the subwoofer power amp needs a 10 db boost. I'm sure not trying to start a war here, just need to fully understand this.
I would really appreciate it if anybody disagrees with anything I have in my outline above that they would clarify it.
Thanks everybody for your input.
Rod