Spacialisation a practice by which the composer or audio engineer utilises multi-channel audio systems and mixing techniques to manipulate how sound is percieved in a space. Most commonly used in gallery, art installation settings, and cinematic settings, spacialisation allows for sound to be percieved as “three-dimensional” (Lombardi, 1997), creating a listening expereince much more grounded in realism.

Before delving into playing with spacialisation, it is important to understand the customs and “laws” that surround the practice:

The Pan Laws

Linear Panning: The gains of the left and right channel should sum to 1. The channels will be panned at a 45 degree angle so that the sound reaches a “sweet spot” in the centre. Linear panning commonly has issues with phasing.
Constant Power Panning: Similar to linear panning, but the power is proportional to the squared amplitude, boosting the signal at the centre.
-4.5dB Pan Law: Considered a compromise between linear and constant panning, the -4.5dB pan law splits the difference between the aforementioned.
Ultimately, when a signal is passed centrally, the same output will be in both the left and right channels, which will cause a drop in signal at the centre.

The different surround sound set-ups

Quadrophonics / 4.0 Surround Sound: In this set up, four different speakers are placed in four different corners of a lsitening space, each channel playing back independent signals to one another. Introduced in the 1970s, 4.0 surround sound is designed to allow a listener to feel immersed within the environment of the recording.
LCRS: Left, Centre, Right and Surround Channel.
Diamond Surround Quad: The same tech spec as Quadrophonics but with the speakers face on to the centre rather than in the corners.

Definitions & Techniques: Recording, Mixing + Playback
Mono Sound: Sound Percieved as from a singular source; one dimensional.
Stereo Sound: Sound Percieved from multiple directions; allows for playroom with stereo mixing (utilising the left and right channel).
Image Position:
Ambisonics: A method for recording, mixing and playing back audio in a three dimensional space; audio can be heard from even beneath the listener, as ambisonic labs have mesh floors with loudspeakers placed underneath them.

Institutions + Proponents
IRCAM: A research unit based in France, investigating the fields of music and sound.
Stockhausen: Non-Profit foundation involved in the advancement of musicology, based on the work of Karlheinz Stockhausen.

The use of spacialisation is particuarly important in VR, as it allows for a more realistic experience. We don’t percieve sound in everyday life the way we do in headohones, or through stero speakers.