While looking for more free plug-ins to slake my thirst I ran into LineUp by developer NuGen Audio. You need to sign up for their newsletter to get the plug but I decided it would be worth the registration. Among others minor functions, it has the ability to delay one or both channels of a stereo signal a fixed number of samples. After playing with it for a minute it seemed like while it might be nice for restoration type jobs it may not have much creative potential.

Then I remembered a little bit of learnin' I got in recording school with regards to localization in a stereo field. When mixing in stereo you will often use a pon pot (or panoramic potentiometer) to place instruments in different locations in between the two speakers. The way a pan pot does this is by changing the power ratio between the two speakers. In other words, as the instrument gets louder on one side it gets proportionally quieter in the other.

There is another way to move an instrument around the stereo field and LineUp reminded me of this. Timing is a very crucial element in how the brain localizes a sound source. Since, in a normal acoustic environment, reflected sonds will take longer to reach the ear the brain will assume that from wherever the sound came from first is the originating source. Even a very small delay (as little as 1ms) can cause a sound to shift in the stereo field.

To demonstrate I took a short keyboard sample an rendered them out to appear slight right of center using both paorama and the delay phenomenon.

First the original sample:

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Next, shifted right using panorama:

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finally, shifted right by delaying the left channel 27 samples (0.5ms at 48k):

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Although this may not have any practicle application to most mix enginneers it might be something to experiment with on one's own. The phenomenon of timing and placement (aka The Law of the First Wavefront) is at least worth keeping in mind as a general piece of psychoacoustical info to impress friends.