Almost all engineers approach their mixes differently. I like thinking about my mix, from the first track all the way to the mastering stage, like a house.
The first thing you need when building a house is a good reason. Your low end should give you this. It is for this reason that the rest of your mix will be built. If your reason is weak, your whole mix will be weak and ineffective. Just like building a real house, your foundation must be solid. The primary instruments that make up this low end, in most of the music we listen to today, are the kitty drums and bass guitar pieces. These two instruments must be gel, yet clearly defined. If they are not clearly defined, which means the listener can not make the difference between the two, you may experience some issues with your mix. Many home recordings suffer from low and middle frequencies that overlap too much and therefore are not clearly defined.
Once we have our clearly defined low end, we must start building our house, brick brick. The bricks we will use to build the house will consist of the mid-frequencies. This area is much more difficult to clearly define because there are so many things going on in the middle. Guitars, songs, snare drums, toms, keyboards, plus a myriad of others all let everyone compete for the same space in the middle. If you have an undefined intermediate section, your mix will sound very muddy. This is again typical of home productions. The middle area is muddy and it usually interrupts the whole mixture, your house.
So, how do we keep the low end from becoming too muddy? Lets look at our house example. If you attach great importance to a brick house, you notice that between the fourth or fifth brick there will be a small hole. I once asked what these holes were for. His answer, They let the house breathe. It sounds strange to me. Im not a practical man, so I did not understand and left it there. What I know is sound, and I know that our mix needs breathing, especially in the tricky middle area. How do we allow our mixes to breathe in the middle? Well, there are several tricks. First, we can use different microphones on instruments, use different microphone locations, we can set up similar sound instruments in different ways; we can physically set the instruments in space to add a sense of space; we can add reverb to add to space virtually, and / or we can use equalization to separate tones of similar audio instruments.
As you can see, there are many things we can do, either alone or in combination with another that can help us achieve the task of creating a non-muddy, clearly defined breathing part. You are about to give you a much nicer listening experience for you and your fans if you can make your middle section breathe.
The last part of our house is of course the top or the roof. The ceiling comes, as you might expect, to consist of high-end toner, but its not really the case in my opinion. The reason for this is that the high frequencies are usually only harmonics and higher octaves of our root sounds taking place in the low and mid-range sections. Most of the time, if you have your low and middle sections eqed properly and they sound good, its a little bit you need to make the high end. Plus, much of the high end will be accentuated in the final process called mastering. So instead of frequencies to build our roof or ceiling, I like to use dynamics.
Dynamics include compressors and limiter. Dynamic processors help keep the tracks as hot as they can be, which means as far away from the noise floor as possible without distorting or cutting. This is especially important with all the digital equipment we use now because digital distortion sounds quite nasty.
Dynamics can provide a nice, round sound or squash your tracks, depending on what you prefer and whatever compliments your music style. Incorrect use of compression makes recording sound limited, such as entering a room with a very low ceiling. Correct, acceptable, use of compression can, on the other hand, make your recording known as someone entering a room with an open, airy cathedral ceiling. You should feel much less limited and more revered as you enter the latter type of room, and listeners will much more appreciate trying to give them this feeling of hearing aunts.
So there it is. When building your audio mix, remember to build a house and your mixes should be much more professional.