Summary: I had a pair of Sony speakers that had no power source (no batteries or AC adaptor)...and they worked fine for what they were. however, I wanted something that could be low with no batteries, but if I wanted to hear them outside with people talking etc, I wanted to be able to power them up and actually hear the music from my IPOD as opposed to it being barely audible.
Summary: Before buying these speakers, I purchased the Sony passive speakers for $6.00. Those were absolutely terrible. After the wire snapped, I decided to pay a little more for these...best decision I've made in a while. They are much louder than you would believe, and have surprisingly good quality. However, I bought these for a very unique reason. I put these speakers in my backpack to play during and after school, and things like that, and these are perfect for that.