One audio technique which always piques my interest is that of polarity inversion to isolate or remove elements within a recording.
While the common approach of separating a stereo audio file will result in a left and a right channel, an alternative method will reveal a third, middle (mid), signal from the recording. This mid signal will contain all that is common to both left and right channels, but nothing which occurs solely in the left or the right channels. The remainder makes up the side signal, essentially a stereo signal minus the elements which were in the middle.
Basic inner workings
The audio mastering process is the greatest proponent of this system as it allows greater control of levels and sound processing in a mixed-down stereo file than would be allowed by processing solely in the left-right spectrum. But… There is fun to be had by mere mortals, too.
Two interesting possibilities present themselves for music producers and remixers: First, a switchable tool which reveals a summed mono output is invaluable when working on music destined for nightclubs, as the vast majority of these sound systems output in mono. Secondly, being able to solo the sides signal can provide hours of listening fun – it truly is a side of your favourite recordings you’ve never heard before. Just play anything released after the stereo phenomenon struck the world in the 60s and you’re likely to be impressed with elements of the song that you’ve never heard before.
I have designed a plugin to fulfill these desires. If you’re a Reaktor owner, load this ensemble in to your Reaktor FX plugin and import your fill of classics for the unveiling.
Download (v 0.8)
