Sound System

Hi. I am looking for a new audio system for my Macbook Pro. My Logitech z2300 system (which I really didn't like all that much but it was one of those deals that you cant pass up) died about 2 months ago and ever since then I have been looking for a replacement. I have read countless reviews on all kinds of system from dedicated computer 2.0 and 2.1 systems to bookshelf systems and I cannot seem to get a straight answer from anyone.

I am looking for a system that sounds great when the volume is low but also has the ability to fill a room. I don't really care about size and it doesn't really matter to me if it is a computer system or a bookshelf system. Bass is important to me, I don't want it to be wall shaking but I want it to be strong and pack a punch. I listen to mostly metal, rock, and techno but also jazz and classical on occasion. I'm not an audiophile by any means but I definitely appreciate high quality sound. The system only needs to have one input and It doesn't matter to me if it looks pretty or not. Last but not least I would like to keep it under 300$.

I honestly don't know if there is anything that meets my needs but I thought it was worth asking.

Thanks for taking the time to read this and thanks in advance for the help!