You may need to take a minute and check out a few videos on mixing/mastering. If you turn up the volume on your track and it crackles, then there is probably a problem with your mix. For a quick start, cut out all frequencies in your track under 30hz for a more clear low end and then cut all above about 14000hz so there isn't too much high end. Also one big tip, before you boost the overall volume of your track, make sure the mix isn't already peaking. You want to achieve an initial mix that doesn't peak past something like -6db so that when you make your track louder in the master process it doesn't distort. Check out the tutorial topic in this forum and others on youtube, that is just a small part of mixing/mastering.