I recently went thru the process of digitizing some old albums to .wav and burned some into CDs. One is one of those "Original Master Recordings" of I Robot. It is very clean sounding on the CD... though still probably only 98 percent CD quality. I also converted these .wav's to FLAC (with the highest compression using dBpowerAmp).
Playing the CD and then the FLAC's on my VW Monsoon HU I could hear that the FLAC's are much better than the mp3's I've been listening to. But the CD was still cleaner sounding.
I am assuming this is because the Moonsoon HU is lacking in quality (it also adds significant background hiss by itself.)
I do want to upgrade to a Kenwood and go thru the process of hacking the cable and firmware so that my VW Phatbox will work with it.
BUT is the Phatbox as good as the Music Keg? IF it isn't, then I'd rather get a Keg. I know a new HU (which Kenwood DD will give the best sound??) Of course money is something of an issue, so if the sound of the Keg versus the VW Phatbox isn't really noticeable, then I'll keep it.
I won't say that the rest of my car system is "audiophile" quality, but it is pretty good. The CDT Audio speakers along with the Infinity amp produce nice, clean sound.