Quite possibly neither.
Not all Cd's a re created equal. Simply put, some CD's simply suck. Some CD's sound excellent.
As far as your level setting on the receiver, I wouldn't worry about it as long a you can get sounds that are "loud" enough for you.
At some point, when your listening tastes gel a little more, you might find you will want other speakers, though. Speakers that are "loud" for PA work might not sound as good at lower levels in a home environmernt.