The appears to be a bug with Surrounder+ effecting the way LFE input is used under different settings.
Depending on the order in which certain options are selected, you get different results.
i.e.
Load Surrounder+.
Set the mode to 2.1 with Surround OFF ("Use Subwoofer Output" disabled).
- Note how LFE input is used in the microcode:
- - macsn fL, lb, in_lfe, 0x40000000;
Change the mode to 5.1 with Surround OFF ("Use Subwoofer Output" disabled).
Change the mode back to 2.1 with Surround OFF ("Use Subwoofer Output" disabled).
- Note how LFE input is used in the microcode now:
-- macsn fL, lb, in_lfe, 0x0;
This bug also effects other modes, so depending on the order in which certain settings are changed (when "Use Subwoofer Output" option is disabled), LFE input may be mixed in with other channels, or may not be used at all (i.e. same setting giving different results at different times).
BTW: This is not the only bug, there is also the bug(s) mentioned in the following thread:
Surrounder+ bug (with 10k1 models)
I will take a look at the code, and see if I can find the specific problem, etc (when I have a chance to do so).
-Russ