Oct 20, 2011

Auro-3D: sound from all around

2 min read

Sound is 50% of the movie experience, George Lucas once proclaimed. Surprisingly, though, since the introduction of 'surround sound' in the early 90s, audio technology in movie theaters has almost ceased to evolve - while cinema projection has gone through a spectacular 3D revolution. But it looks like things are about to change.

So, why has cinema sound evolution been stagnant over the last two decades? A possible explanation lies in the widespread belief that, while our brains observe images very consciously, audio acts on a much more subconscious level - and so it's considered to be less important.

Nevertheless, most movie directors share the conviction that the aural component of a movie has a very strong emotional impact on the audience, and, therefore, adds significantly to the overall cinema experience.

Adding the extra dimension

Traditionally, cinema audio has been a 2-dimensional 'surround' world - but in the wake of the overwhelming 3D wave, sound is now exploring 3D as well. The reason is simple. By adding an extra dimension, the emotional impact of sound becomes even stronger than before, which makes it the perfect companion for visual 3D.

Voices from above

To produce a true 3-dimensional sound, you need a speaker layout with three spatial axes (width, depth and height) instead of two. So, converting an auditorium to 3D sound comes down to installing an additional set of height speakers, plus a center speaker and an LFE (Low Frequency Effects) channel. This basic 3D sound speaker layout is called a 9.1 configuration: 8 speakers, positioned at the 8 corners of the auditorium, the center speaker, and the LFE channel. In practice, the 3D speaker layout is defined for up to 13.1 channels, with 11.1 being the ideal solution for commercial movie theaters.

Fully compatible

To create a high-grade 3D sound system for digital cinema theaters, Barco has teamed up with Galaxy Studios, one of the leading sound studios in Europe. This collaboration has produced Auro-3D: a fully immersive 3D sound solution for cinema theaters that is 100% compatible with existing 2-dimensional audio standards. In other words, Auro-3D allows you to reuse the current formats and channels for content generation and distribution.