I am also experiencing volume issues (glitches). If I set ringtone volume to first step up from silent, the feedback sound appears low (as I'd expect) but when I receive a notification or call, the volume is then at full. Media volume is set to silent, Alarm volume also silent.
I too migrated from CM9 based ROM (OpenSensation) after a full wipe.
I've not tried anything yet at ROM install stage to see if it's the Beats Bass boost mod causing the problem. Will try that next (installing without the mod) to see what happens.
Apart from this issue/feature, this is a fantastic Sense ROM (from someone who really prefers non-sense).
Great work dev.
**Update** I've reflashed and this time opted to select the standard Beats with HTC stuff sound option and not the Beats Audio mods by mudhi. I think this has done it as after dropping my volume down to just above silent (very quiet) and then sending a text to my phone, the notification sound is now exactly as it should be.
I'll update again if anything changes but for now, so far so good.
Ok then so probably the bug is within htc music app and/or any other files included in mudhi's beats mod. I'll take a look tomorrow morning and see if I can spot anything glaringly obvious