Differences in recording for surround

The recording stage is the first stage after composition and is when an artist’s song is first introduced to the studio. At this point the artist should have a clear idea of what each piece of instrumentation will be doing in the music. This is the chance to experiment with these ideas now that it is possible to listen back to their artwork. This production stage should result in all of the instrumentation being recorded and structured to the artist and sound engineer’s satisfaction; no new instrumentation is normally added after this stage.

So what does the recording stage involve? The recording stage involves the capturing of the artists music via microphone or direct input to the mixing desk. Different sound engineers will utilise different methods while recording and it is important to note that there are no set rules to the production of music, it is completely subjective. Although the creation of music is a subjective thing, recording techniques and methods have been devised specifically for the capturing of sound in stereo and 5.1 Surround Sound and these methods differ between the two reproduction systems.

The invention of the stereo system of course saw to the invention of stereo recording techniques. Stereo recording techniques normally involve two microphones spaced or angled in a specific way towards the sound source. The signal from these microphones is then sent to the mixing desk where they are panned to the corresponding left or right speaker e.g. left microphone panned to left speaker, right microphone panned to right speaker. Stereo microphone techniques create the impression of space and the directionality of sound sources; this is due to inter-aural time differences and inter-aural intensity differences, the same way that human hearing localises sound. It is important to note that during stereo recording not all techniques use two microphones such as, close micing, which is where one microphone is place close to the sound source and then recorded and panned appropriately.

All Stereo techniques can be applied in the recording stage of 5.1 Surround sound music production, however panning methods can differ as there are extra centre and rear channels. Similarly to the stereo reproduction system, 5.1 surround sound has it’s own microphone techniques, some of which were adapted from stereo techniques. Surround microphone techniques can utilise anything from two to six microphones again with specific spacing’s or angles.

Although some surround techniques were adapted from stereo the principles upon which they are based are slightly different. The stereo system is based upon the principle that the listener is facing the music source, with one speaker on the front left and the other on the right. Surround Sound, however is based upon the principle that the listener is sitting in the middle of a listening space being “surrounded” by music, this means sound sources are not only localised at the front like stereo but all round the listener immersing them in the music. As a result of this, in the recording stage of surround music more consideration is taken in terms of the structure and panning of instrumentation between six channels rather than stereo’s two channels

Quadrophonic Era

The Quadrophonic system relies of four loudspeakers place right, left, right rear and left rear. This System was to be introduced to the market place at the start of the 1970's and died out within a decade:

Quadrophonic System

http://people.xiph.org/~xiphmont/surround/demo.html

Accessed: 16/04/13

In order to begin talking about the Quadrophonic Era we must first know the difference between Matrix Encoded multichannel audio and Discrete multichannel audio:

Matrix Encoded:

Matrix encoded multichannel audio is where the surround and centre channels are created by using combinations of the original left and right stereo channels, otherwise known as Upmixing. Seen as the centre and surround channels will include information that is also in the front left and right channels, matrix encoded multichannel audio cannot isolate sounds to the surround channels. 

Discrete: 

Discrete multichannel audio is where the centre and surround channels are encoded on separate streams  rather than being matrixed from a stereo signal. Discrete audio allows sounds to be isolated completely to the surround and centre channels creating better directionality and localisation. 

The Quad Era saw many different engineers design different matrixes that would help reproduce 4 channels of audio from a Vinyl disc, such as Peter Scheiber's 4-2-4 matrix that allowed 4 channels to be compressed into 2 and then restored to 4 again using wide band phase-shift networks in the encoding and decoding process. One of Scheiber's demonstrations of his matrix to CBS executives caught the interest of Benjamin B. Bauer, who then went on to design the SQ (stereo-quad) matrix with the help of the CBS Laboratories. Bauer claimed that his matrix had better spatial attributes and compatibility with stereo and monophonic playback and it was this invention that earned him his nick name of the "Quad Father", however it was not long before many other matrixes were invented such as the, QMX matrix from Duane Cooper, QS matrix from the Sansui Corporation and Ambisonics from Michaul Gerzon in the UK. 

Now that there were so many different quadrophonic matrixes available, it wasn't the question of which matrixes would become the standard, but whether either matrix or discrete surround audio would become the standard for multichannel audio. The invention of the CD-4 record from the JVC Corporation and RCA Records saw the end of this debate as it allowed the reproduction of discrete audio. 

Although the Quadrophonic Era saw to many new inventions such as multichannel audio matrixes, it had failed to become a great success. There are many different speculations as to why the quad system had failed such as, there were too many competing formats for the music dealers, and they would have to provide all of their products in three different formats, stereo record, cassette tape and quad record, which didn't see any extra profit to the dealers and record companies. Other reasons for the Quad Systems failure were that the market was not warming to the idea of having two extra loudspeakers in there listening space and also record producers were not able to exploit the medium as they believe it:

"locked them into rigid four-cornor reproduction"

Emil Torick

Highlights in the History of Multichannel Surround

Audio Engineering Society Journal, Vol.46, No. 1/2

January/February 1998

Emil Torick also describes how the Quad Era failed in and interview with the AES:

http://www.youtube.com/watch?v=rJhC7VchDuo 

accessed: 17/04/13

Having discussed the reasons for the Quad System's failure in the music industry, it is interesting to relate this to the 5.1 Surround Sound System, which is now a standardised format. The 5.1 System is hugely popular and the standard for film and becoming more and more popular in the gaming industry with the invention Surround Sound headphones. However it's uses in the Music Industry has been more elusive, is this because of the same reason as the Quad Era? Do record companies not produce 5.1 music material because it would not increase profits? Is Stereo then the standard format for the music industry?

References:

Emil Torick

Highlights in the History of Multichannel Surround

Audio Engineering Society Journal, Vol.46, No. 1/2

January/February 1998

 http://www.youtube.com/watch?v=rJhC7VchDuo 

accessed: 17/04/13

Holman Tomlinson, 2008,

Surround Sound Up and Running,

Second Edition

Exposition 3

This sound exhibition in singapore talks about immersing yourself in sound and has different interesting things in which people can interact with:

http://www.science.edu.sg/exhibitions/Pages/SoundExhibition.aspx

As part of my project i believe the best way to portray my work is if the visitor can interact with it and possibly even change parts of it to their liking. One way in which i could do this is if i provide a mixer in which the visitor can alter the levels of each individual speaker channel in the surround system: allowing them to hear parts of the music in a way that they wouldn't normally be able to do by soloing individual channels.