This is a question that is often asked by many in this day and age of the D.A.W. (Digital Audio Workstation).
Well, the answer is two fold. Yes and no!
Yes, you can generally mix and master your own song if you have knowledge of signal flow, a general understanding of how eq's, compressors and limiters work; as well a couple of years studying the over all sound of a great mixed and mastered song. But, if you don't have this knowledge, the answer would be no!
Most people think that you can pull up a couple of presets on a plug in and that's it. Naw, you are in for a rude awakening when you find out that your song doesn't have the clarity, depth and presence found with most of today's hits. Now granted you will have a couple of songs that are mixed and mastered like trash that will eventually become hits, but would you want to chance it! I wouldn't because as a radio dj as well, it often gets tossed aside.
So as a rule of thumb it is always better to have someone mix & master your song who has the experience if you want your song to be able to compete with the big boys. There are some things that only come with experience and knowledge of the craft, mixing & mastering is an art just as producing and writing a song. It's all about the ears and the knowledge.
Now, if you are doing a mixtape or something along those lines, I say save the money and do it yourself. But when the time is ready to make your song available for sale or radio play, nothing beats a professional.
If you have any questions about mixing, mastering or recording in general feel free to comment and I will do my best to reply.
As always keep the music bangin'!
I am a total music fan and enjoy working in the studio. To know me is to know music.