What is the function of a 'subwoofer' in an audio system?

A subwoofer is specifically designed to reproduce low-frequency sounds, typically in the range of 20 Hz to 200 Hz. These low frequencies contribute significantly to the overall audio experience by providing depth and impact, particularly in music and film soundtracks. This enhancement of low-end frequencies allows for a fuller and more immersive listening experience, making certain sounds like bass lines in music or rumbling effects in movies more pronounced and engaging.

In contrast to a subwoofer, other components of an audio system are optimized for different frequency ranges, such as mid-range speakers for vocals and instruments or tweeters for higher frequencies. Therefore, the function of a subwoofer is unique and critical in delivering low-end sounds that enhance the overall audio experience, affirming why the correct answer is C.