The first rule of mixing is: There are no rules.
Yes, audio engineering is a science... there are many important concepts that must be understood and followed (proper gain management, minimizing phase problems, analog to digital conversion, bit-rates, etc.). But following the rules alone won't get you there.
The goal of mixing is to create a piece of music that creates an emotional impact. You have to "find the magic" in a song and bring it out in the mix. Mixing is at least 80% art.
So how do you find the magic in a mix? One important technique is to listen in a new context - as a "first time" listener. This is particularly challenging for the artist, band, or engineer who has been working on the project for weeks or months, listening over and over and getting more and more accustomed to the working mix. The first time listener is listening to the song as a whole - the groove, the mood, the feeling. A small timing error on a drum fill or a particularly loud bass note could totally distract this listener. They can't tell you what was wrong, but they are no longer "in it". On the other extreme, a perfectly balanced mix with no surprises will bore the listener within 30 seconds. In today's world, that listener is already on to another song.
The remainder of this article describes an approach to mixing focused on connecting with the listener.
If you have a mix you've been working with, save it off and start fresh. Set all of your faders to -6db. play the song and turn down tracks that are too loud to get a basic balance (we are keeping lots of headroom). Now listen to the song like you've never heard it before. Turn it up a bit so you can feel it. Listen for any "jarring" moments - where something sticks out and you are no longer just groovin' to the beat. FIX THESE. They are the biggest indicators of amateurism in a recording! Listen through a couple of times to make sure the rhythm is solid and there are no notes that distract (volume or tuning).
Now listen again from the beginning, but put on a different filter. Listen for the parts that are particularly cool. What are the hooks - the parts that people will have stuck in their heads? Now - how can you emphasize these parts in the mix? There are as many ways to do this as there are cool parts in songs, but here are some examples:
Lets say there is a particularly nifty counterpoint between bass drum and bass guitar leading into the chorus. If there is also a guitar build-up at the same time, try muting it or applying a high-pass filter so it lets the lower frequency bass instruments shine through. Apply a slight upper-mid boost to the kick to accentuate the rhythm (or a compressor with a medium attack to add extra punch).
Another example - a guitar riff that fills the spaces in the verses. Again, try to remove parts (or move them out of the way) that compete with the riff, such as the rhythm guitar. Adding a slight flange or phase is a good way to draw attention to a part. Modulate in other ways such as vibrato or tremolo.
There are more dramatic ways to draw attention to a track or a part. This is where you really break the rules. Trust your ears and go crazy with the EQ. Have a gate that triggers the pan location, so louder parts push toward the center or edge. Go lo-fi or add distortion (distortion is subconsciously associated with loudness by our brains). Be sure to double-check these sounds the next day (with fresh ears) and comparing to a reference song to make sure you didn't go too far. Hit songs push the boundaries with fresh sounds, but it is easy to just come out weird or unprofessional sounding if you aren't careful.
This is overly simplistic, but sometimes it is just a matter of turning these cool parts up. Use your mix automation! You will likely need to change the volume, pan or effects of a track depending on what else is playing. For instance, a drum intro may sound too wet if you leave the effects where they sounds best when all of the instruments come in. You may want to cut the reverbs back for the intro.
Time for the third filter: does the tune hold a new listener's attention through it's entire length? This one is a balancing act between keeping it interesting and being distracting. Often the easiest way to keep things interesting is by muting parts earlier in the song and adding them in later. If your song is just straight guitar, bass & drums from beginning to end you can still pull this off by adding layers and different timbres. Copy your guitar track to 3 additional tracks. If you have a direct guitar track you can apply different modeling plug-ins to each track or re-amp them. Start with a fairly bright tone and roll off the lows below 200hz. When you get to the first chorus add another guitar track with a thicker tone. Play with muting these various tracks at various locations. The changes don't have to be dramatic - remember, you don't want to distract, just keep it interesting.
Getting an impartial, fresh perspective on your song can really help take it to the next level. It is partially for this reason that specialized mix engineers have become more and more popular. At the very least, take a week or longer break between tracking and mixing. When you come back after this break, it may surprise you how many little things sounded ok before but are now irritating. You just took a step toward being a first time listener.
By: Deron Daum
Article Directory: http://www.articledashboard.com
Deron Daum Audio Engineer MagicMixStudio.com