Each cigar box guitar sounds unique. The types of wood used for the box and the neck, as well as the size and shape of box will alter the sound of the guitar. Beyond that, how you play it and what you play it with will change the sound as well. If playing through an amp you can easily alter the sound by using your amp's built in equalizer.
Below are some examples of how a cigar box guitar can sound.
Cigar Box Guitar Example 1
Cigar Box Guitar Example 2
Cigar Box Guitar Example 3