GFX Sound Enhancer allows to make your sound colorful. There are three supported effects - 3D-surround, hyper bass and fidelity which can definitely improve your sound. It is easy to use and no addition knowledge is needed.
There is a wide variety of presets which also help to tune you sound.
Simple sound enhancer, has a few presets, might be worth to take a look at if you want to artificially enhance your output.