xawtv and frequencies

I have the latest stable xawtv installed on my Suse 7.2. Does somebody know why there are only two frequency lists in the xawtv package and where they are used for. The choices in xawtv are 3 cable and 12 broadcast ranges. Does xawtv uses these frequency ranges? Is the sound frequency always a certain value away from the image frequency and would playing around with sound frequency in such a list influence the sound reception, in other words, could I get sound by playing around with the distance between the two frequencies? At the moment I have a good image but the sound is some 20 ticks away from the accompanying picture.