I think you're getting speakers and channels mixed up. Have a look at my screen grab:
Chanels:
This should match the source. So Music = 2. DVDs = 6 . Games = 8. There are exceptions but that will cover most of them.
Sample rate:
I generally set it to max but some would argue that you should match your source - so CDs = 44.1khz etc.
Analog Out:
This should match your listening equipment - so for you that would be headphones.
You will see where I've checked Dolby Headphone. Clicking on this box gives access to the 3 different presets.
Wrong I'm afraid. The sound is coloured by default as Windows resamples anyway. Even Hi-Fi mode does not give unaltered sound. To get pure, unaltered sound you have to use the AISO driver and a compatable player like foobar2000, setting bit-rates accordingly. This is how I listen on headphones with binaurally recorded music. For other headphone use I generally use dolby headpone and however many chanels the material was recorded in. Most CDs are engineered to be played back on stereo speakers. Dolby Headphone with 2 channel mode simulates this.
To the OP: Like anything else - don't just take my word (or anyone else's on the internet) for it. Try different settings and see what you like.