Re: SRT High performance audio settings
Be sure you're not trying to optimize in XM/Sirius. HD Radio, high quality MP3 from SD card or USB, bluetooth streaming, or Slacker/apps have substantially better quality in general. I think either Sirius compression is just too much, or the system decodes it poorly. Sirius quality is notably worse across the board.
FYI mine is Bass 0, Mid +2 and Treble maxed, but obviously this is all subjective. I have terrible tinnitus so generally like the treble maxed out or things sound dull.