Usually a box with a larger speaker driver located out of the way or in the front stage of a home theater, the subwoofer is what packs the boom to round out the range of frequencies that you hear. This is part of the source material that most people miss out on when they don’t have a subwoofer. A good subwoofer makes ALL the difference when you are enjoying music or a movie and want to be enveloped in the full intent of the material you are enjoying in its entirety.