Since day one, I set my Audician to line out. I maxed out all the volumes in SETUPSA and controlled the volume on the speakers. My powered 2.0 speakers sound great. But the headphone jack on the speakers is loose. When there's a good connection, the headphones sound great, when it gets moved, I can hear it dropping to mono. So I ordered one of these:
http://www.ebay.com/itm/3-5mm-Stereo-Headphon … Y8AAOSwHnFV0vko
to make it easier to plug my headphones directly to the line out (without having to pull the PC out from the wall and reach around to plug in). What I discovered was that the headphones have almost no volume with the sound card set to line out. Yeah, I know, obvious. But I didn't realize it would be nearly inaudible. I thought it'd be a little quieter. So I decided to try the speaker out jumper setting. First, it was way too loud and hissy. So I went into SETUPSA and played with the volumes. I realized I didn't need to mess with the SB Mixer volumes, only the Master Volume under WSS Mixer. I ended up dropping Master Volume from its maximum of 15 all the way down to 1. To my ear, this gives the perfect volume through both my headphones and powered speakers, and I don't notice any hiss or other noise.

What's weird is, I expected that since my headphone volume was higher with speaker out vs. line out, that my desktop speakers would also be louder, but that doesn't seem the case. Volume is about the same with the volume knob set to the same spot. At any rate, I thought it was cool that setting the Master Volume to 1 solved my problem. 😀 Since Master Volume is in the WSS section, I didn't even think it did anything unless I was trying to play a game that supported WSS.