All - fyi
Sound quality issues on myth front end??
If you have analog sound related issues, ensure that 48000 is set BOTH at the mythtv-setup-->capture cards--->v4l AND on the myth front end (which seems to default to 32000) to get there, it's in Recording Profiles -> Software Encoders -> LiveTV, then just set up the encoding options, audio is on the second page.
Wiki updated: http://wiki.linuxmce.com/index.php/PcHDTV_HD5500#Troubleshooting