Here's something vital: Music breathes, and so should your mix. This doesn't mean just turning up the volume of an instrument for its solo! Your audio should always be in motion; even the slightest movement of volume levels makes the mix feel alive. Minute changes during the playback of the songs will do wonders, making your music feel more alive. It's a trick that so many engineers use. Keep those faders in motion, even just slightly. It will make everything sound better.

Automation

If you own a studio-in-a-box or computer recording system that supports mixing automation, you'll enjoy this section. Mixes aren't static. You can't just “set it and forget it” as the TV infomercials often say. A song and its resulting mix is a living, breathing thing that changes. Guitars get louder for solos, drums duck under vocals during verses; things change. If you're working on a system that you can't automate, such as a tape-based studio, or if you're using a mixing console, you'll have to know exactly what's going to change throughout the songs and adjust the levels and other parameters live upon playback. In the old days, this was called “playing the console” and was an art all to itself.

Digital technology allows you to plan all the movements of faders, effects, and pan settings in a process called automation. You go through the tracks as you mix, and you record the motion of the faders into a special track called an automation track. Once you've recorded all the movements, the automation track plays back and takes care of all of the changes in faders and so on. It's a great thing to have if you work alone. Most studios-in-a-box support some level of automation, and computer systems give you an incredible amount of control.

Fades

How will a song end? Take a good listen to the end of some of your favorite albums, and you'll realize that none of them just stop; they all have some kind of smooth fade. How do you achieve a smooth fade? If you use a digital system, you can use the fade-out option in the editing menu. If you have automation capabilities, just automate the master fader at the end of the tune. For those of you who have to move the fader by yourself, just evenly yank the master fader to zero at the final mix down to achieve a smooth fade.

“Flying fader” is the name given to a mixing board with motors that move the faders automatically. After you've recorded automation for your songs, the fader “flies” by itself along with the volume changes you've recorded via automation. Flying faders were once found only on the most expensive mixing consoles, but now more and more manufacturers are putting motorized faders in home studio products.