The EM Poll

Twelve Common Mixing Mistakes

Jul 1, 2007 12:00 PM, By Michael Cooper

           

The Chorus Doesn't Climax

You had high hopes for your new power-pop ballad, but something is holding it back. Your tracks were all captured with plenty of dynamic range, the performances were killer, and the arrangement positively soars during the hook. Yet for some reason, the chorus just doesn't deliver the big payoff it should in your mix. It's time to look at your mix-bus compressor settings again.

Sometimes an engineer will set up the mix-bus compressor for a big, in-your-face sound at the beginning of mixdown, when working on relatively quiet verses, and will just assume it's going to sound even bigger during the choruses and other climaxes. A compressor with too low of a threshold and too high of a ratio will suck the life out of the hook when it hits — sometimes the chorus will actually sound lower than the verses. Raise the compressor's threshold and lower its ratio to no more than 2:1 to give the hooks room to explode. You might also need to back off the compressor's attack time a bit.

Washy Sound with No Depth

Adding reverb to a mix is a great way to make it sound bigger. The larger the implied acoustic space, the more depth and width the production takes on. But running virtually everything through reverb in an attempt to make the mix sound huge is a common mistake of neophyte mix engineers.

Something can sound big only if something else sounds small. In part, it's the contrast between close-up and far away that gives a mix depth. (The nuance captured by superior mics and mic preamps is another contributing factor, but that's a discussion best left for another article.)

When many tracks are drowning in reverb, everything begins to sound indeterminately far away, and there is not enough of an anchor for the brain to get a picture of what is psychoacoustically up-close. Not only has depth gone out the window at that point, but the mix also takes on a washy character dominated by diffuse echoes that blanket any semblance of detail and punch.

One solution, of course, is to make some tracks very dry. You might even need to make a lot of tracks completely dry in order to attain the depth you desire. Instruments that produce inherently sustained or reverberant sounds, like cymbals and strummed acoustic guitars, often benefit by turning their reverb sends way down or completely off. That's especially true of dense arrangements that are prone to drown in ambient soup. The acoustic guitar already supplies built-in reverb from the resonating chamber that is its body. Piling on a bunch of additional reverb makes little sense, unless that instrument is being played in short, percussive bursts such as during a largely monophonic introduction or solo.

Despite the foregoing, there are instances where a healthy dose of time-based effects is needed to create the desired sonic landscape. In such cases, try adding predelay to some of your reverbs, or try substituting single echoes or multitap delays for reverb effects. These alternatives allow the dry signal to voice before the effect kicks in, giving a front-to-back effect in the soundstage that can really enhance perceived depth while preserving detail.

Another remedy for a washy mix is to eliminate one of the channels of a stereo track, thereby reducing that track to mono. Converting most of your stereo tracks to mono will help provide the pinpoint imaging that is a remedy for a washy mix. Conversely, using a lot of tracks that were recorded with spaced-pair stereo-miking is a recipe for mud soup. Each of those tracks is a rendering of an instrument playing in an acoustic space, and simply panning them differently to separate them won't necessarily lend focus and depth to your mix.

Panning a few stereo tracks across the stereo field is a common strategy. But if you pan one stereo track hard left and at ten o'clock (for left and right channels, respectively), another at ten and two o'clock, and a third at two o'clock and hard right, what have you accomplished? You now have three small rooms in a left-center-right arrangement superimposed over whatever other acoustic spaces are implied by added reverb on other tracks. No wonder the mix sounds washy!

In summary, to clean up a washy mix: Keep a number of your tracks mostly or completely dry. Mute one side of one or more stereo tracks. And use discrete delays and reverb predelays to create depth without sacrificing detail.

FIG. 5: A previously rendered track of a Sonic Implants Symphonic Strings ensemble section is patched through the Waves S1 Stereo Shuffler plug-in to increase its stereo width and create a dreamier sound.

Collapsed Stereo Image

Suppose you've hard-panned a number of tracks, but your mix still doesn't sound as wide as you'd like. What's wrong with this psychoacoustic picture?

Your hard-panned tracks might have too much bottom end. Bass frequencies are inherently omnidirectional, meaning it's hard for the human ear to determine where they originate. That's because bass frequencies have long wavelengths, and easily wrap around the listener's head to either ear with minimal phase difference.

From a stereo-field perspective, tracks that are panned hard left and hard right are potentially the most directional elements of a mix, whereas center-panned tracks are the least directional. The more the prominent omnidirectional bass frequencies are in hard-panned tracks, the more the hard-panned tracks' perceived positions in the stereo field get pulled toward the center. Conversely, rolling off bass frequencies on hard-panned tracks will move them farther from the center.

FIG. 6: The iZotope Ozone 3 plug-in bundle includes a Multiband Stereo Imaging component that can independently widen the stereo image of up to four frequency bands of a track.

There is no magic frequency at which omnidirectionality occurs. Sound becomes progressively more omnidirectional as its frequency gets lower. So the lower in frequency the bass content of a panned track, the more it will move toward the center (assuming that the high frequencies also present in the track don't compensate). Even hard-panned tracks with a lot of low-midrange frequency content will move slightly toward the center image.

To make a mix sound wider, try rolling off the bass and possibly some low-midrange frequencies on hard-panned tracks. Also, hard-pan tracks with lots of high-frequency content — such as cymbals, shaker, and piccolos — to gain more apparent width. If you still need more width in your production, running a single stereo track through a stereo-imaging plug-in such as Waves S1 Stereo Shuffler or iZotope Multiband Stereo Imaging (which is part of the Ozone 3 multicomponent plug-in bundle) will do the trick nicely. Be judicious, however; using this kind of processing on multiple tracks or on an entire mix can quickly make your production swim in a washy, diffuse soup (see Figs. 5 and 6).

Read more of this Electronic Musician article on how to correct common mixing mistakes