Can you comment on the sound quality of the CAPS 2.0 versus<br />
<br />
1)MacBook Air, iTunes, battery power<br />
2)MacBook Air, iTunes, Amarra or Pure Music, battery power<br />
3)MacBook Air, iTunes, AC power<br />
4)MacBook Air, iTunes, Amarra or Pure Music, AC power<br />
<br />
<br />