My Portable MP3 Player Speakers take 3 AAA batteries at 1.5V each. How many watts is this?

I want to buy a louder set of travel speakers with more bass and have seen some on ebay advertised as having 4 watt output. I don't know what the output is for my current set of speakers so I don't know whether this is better or not?!

Can you help?

The power available from 3 AAA cells is puny - a watt or less.