For PC with good sound card these Speakers paired with powered sub will be a good enough for 10x12 by 10 feet to ceiling that's if you don't crank it too loud. even watching movies they're good and I found better when playing music as It's produce crispier sound (even with ALC 850 or higher integrated sound) than Z5500 satellites.
If you’re connecting it to DVD, Game console or mini system, IPOD etc. then the Z5500 would be just fine since it has digital decoder built in and of course you can turn down the volume if it's too loud.
Books shelves type speakers are much better of producing good sound quality but they require power amp.