Are they loud at the max setting, and are they clear with no crackling? My current 4-5 year old Dell 17" Inspiron absolutely blows me away with how loud and clear it is, and it's something that I use frequently. I know apple tends to have a bad track record with loudness in their external speakers, or extreme crackling (personal experience). Just wondering how your experiences are with the speakers? I have heard the 17" speakers and they are phenomenal, but they also use 4 speakers and a woofer, and I believe the 15" only has 2 speakers?