Mixing is the art of blending everything together to make one single stereo track. We are taking all the tracks that were recorded separately and combining them into a single stereo image. There are 4 main things we use to do this. These are Equalizing or EQ, Pan, Volume, and Effects. By using a combination of those 4 tools we can provide a sense of separation so our ears will hear each instrument. We can clear up any mud or tracks that are hard to detect.
There are some physical tools you need to achieve a well-balanced mix. First you need a room to mix in that is acoustically tuned. It needs to have the proper sound proofing. It needs to deal with room reflections so certain frequencies and sound waves are not exaggerated or repeated through a natural reverb process.
Next you need a set of near field studio monitors. You don’t get a true representation of the signal you are mixing from regular consumer speakers. This is because those speakers are designed to make the sound better and quite often regular speakers and head phones exaggerate the frequencies and add a slight distortion in an effort to make things sound better.
The problem with this is you might mix something to sound great on a certain set of normal regular speakers only to find the mix sounds terrible on a different system. Near field studio monitors will give you a true representation of the audio signal without adding anything that is not in the original signal.