This one goes out to Post Paint Boy…

If you are new to home recording and your tracks sound unprofessional and quiet, this is most probably due to either bad or no mastering. Mastering is essentially a process which concerns the output levels of your final musical piece. In particular, it’s about trying to get your recordings to an appropriate listening volume without sacrificing the sound quality too much. It is also about getting different tracks sounding good on one CD.

You might be thinking, ‘Why can’t I simply turn up the output volume of my recording to get a louder track?’
Well, the answer is that by doing this, you are bound to cut off some of your peaks and create some distorted parts in your song. Also, without using mastering techniques, you are bound to get inaudible verses and painfully distorted choruses. You want a song, which your listeners can hear with ease from start to finish.

There is a fantastic article about mastering here, this is based on an even cooler article by Rip Rowan which seems to have gone missing. It is most definitely worth a read as it explains the basic idea behind mastering and how to achieve a louder overall mix. Essentially, you can achieve your louder mixes by reducing your peaks with compression. With your louder peaks reduced, your track can be boosted without saturating the output. Thus, the quieter bits become audible whilst the louder bits remain loud.

Other posts you might find interesting:
To Limit or not to Limit
Interfacing JAMin with Ardour
An Overview of Compression
Normalisation…Never heard of it!
An Example of Loud Mastering