Knowing that would certainly eliminate some options.
Keep in mind that 'HT systems' might refer to different things/equipment to different people. If possible and your budget permits, I suggest you start with a basic or mid-level AV reciever & speaker/sub separates. They handle music just as well as they handle video signals. And when he's out of school, this equipment would transition well to another apartment where he could upgrade as needed.
I would like to purchase all the necessary equipment to create a decent sound system as a gift for my son's 21st birthday. He is currently in a suite-style set up at school, where I'm sure loud is important, but I would like to be sure "quality" of sound is ensured as well.
I don't think I should be looking at home-theater systems, as they are purchasing a television system separately, and I really don't want to sacrifice music sound quality.
Are there any high-quality "all-in-one" systems where the receivers/speakers/woofers, etc. are a package deal, or do I have to piece this together? My guess is that they will play music off their ipods/phones, but do any systems have cd slots as well? Lastly, if there are home theater systems that are also high-quality sound/music systems I would not be averse to researching those as well.