I'm wondering how you want to use the word. For example, acid rock sounds good to some, and evil to others. Dulcet seems to imply that sweet sounds are good. Mellifluous as well, implies sweet/good. However, if you think the sound of rain is good, or the crack of a whip, I don't think dulcet covers the need. I might choose something that implies my personal taste, something more generic, such as groovy. Again, you're stuck with the fact that groovy doesn't mean sounds good, it just means good. I can't really think of a word offhand that means sounds good, I was just looking for a little clarification.