Recording - November 2011 - 18

Mixing and the Stereo Field
Autopanning and stereo imaging Doing all the above and still not quite happy with the stereo field? A technique I’ll use at times to liven up an “I” mix is to use an autopanning plug-in, which sweeps a sound from side to side in the stereo field. This can also be achieved using panning envelopes or by recording automation if your DAW allows. Listen to “Sweep.mp3” and you can hear an electronic sound moving from right to left and back during the short break. Stereo imaging plug-ins can also be useful to improve the stereo image of your mix. These enhance the perception of a stereo track’s width, by adding phase-inverted signal to opposite channels. This can open up a narrow sound. I’ve found that this process can also diminish the low end of the source. If less bass turns out not to be a good thing, some stereo-widening plug-ins do have a bass makeup control. Conversely, some of these types of plug-ins allow you to narrow a toowide source, and they can be used instead of

Fig. 2

We should be striving for balanced mixes that use the space between 100% left or right and the center, with no one side being louder than the other. Everything balances out.
phrase, then the same phrase is repeated but using the stereo effect, which remains on through to the end of the song. The reverb is a small plate with a delay time of 9 ms. ~ Place the guitar center and use a stereo chorus effect. Reference the example “Stereo Chorus.mp3”. This example has a left delay of 5 ms and a right delay of 9 ms. The modulation frequency is on a slow setting. If you listened to those two examples, you heard that the stereo effect is there, but subtle due to the short delay times. The next two examples use more delay and are examples of the Haas Effect. A principle theorized in 1949 by Helmut Haas, the Haas Effect tells us that we perceive the location of a sound based on which ear the sound first reaches. To use the Haas Effect to create a stereo image from a mono source we make a copy of the mono source, pan the identical sounds full left and right, and delay one side up to 35 ms. Any source that includes a delay of more than 35 ms is not perceived as a single stereo sound, but as two distinct sounds. ~ To do this using a delay plug-in, pan your original source hard left and send it to the delay effect. Set the delay to less than 35 ms, pan it hard right, set the feedback to zero and the mix to 100% wet. See Figure 2 and audio example “Delay.mp3”. This example uses a delay time of 20.5 ms, which is a multiple (1/24) of the songs tempo. Again, for demonstration purposes the first eight bars are in mono. ~ For another way to achieve this in your DAW, not using a plug-in, clone the mono source to a new track. Pan the original hard left and the copy hard right. Offset or “nudge” the copy less than 35 ms before or after the original, and it will sound just like the Delay.mp3 example. To enhance the stereo effect, put one side through a mono chorus effect or use eq on one or both tracks. One effective eq technique here is to bump a frequency of one track up by a few dB and on the other track decrease the exact same frequency by the same dB amount.
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RECORDING NOVEMBER 2011

converting to mono when dealing with a mix containing multiple wide stereo tracks. Front to back So far we’ve been discussing the left and right width of a mix, but there are also techniques you can use to improve the front and back depth of your mix. Of course, mixing in 5.1 surround sound actually allows you to place sound front or back, but we’re talking about two-channel stereo here.

Fig. 3

Recording - November 2011

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