I recorded a couple songs with my SM58 mic and Behringer UM2 soundcard through Audacity and everything sounded great. Until today I wanted to record something and the background noise was ridiculous. I didn't change any settings. I dont know what happened but I couldn't edit the vocals or turn them up because there was too much noise. I played about with the gains etc but still no change. I also recorded a couple of seconds of just silence and the noise is way too high. The only thing I changed is before I recorded Xlr to Xlr. Now I am recording Xlr to Lead because I've left my cable at my friends. Could that make a difference?