The Credibility of Upmixing

Alongside investigating the appropriate 5.1 microphone array to apply in this project, the proposed study also involves defining and discussing the technique of Upmixing. This technique is the process of taking stereo material and then reformatting it to 5.1 Surround Sound. Upmixing is used in the industry today as a way of releasing stereo material in 5.1 when the original multitracks or a large budget are not available. Hugh Robjohns states:

“Often the upmixed version is very credible and pleasant to listen to.” (Robjohns 2001)

This statement forms part of the rationale behind the proposed study, how credible is the upmixing technique when it is compared to a “true” 5.1 recording that provides better directionality and localizations of sound? And will the general public be able to tell the different between the two techniques or is it just the additional rear information from 5.1 materials that creates a more enjoyable experience for the listener?

Robjohns describes a visit to Andrew Walter, one of Abbey roads 5.1 Audio Restoration engineers. During this visit Walter provides an example of the kind of materials that he upmixes from stereo to 5.1 Surround Sound. These materials range from 78rpm shellac records to more modern material such as an Emma Bunton single. Walter conveys to Robjohns that although the original multitracks are available for this single, most of the time the budget and time are not there to create a ‘proper’ surround mix.

“Upmixing, as explained in part five of this series, is a relatively simple process, and can be done using a finished, paid-for stereo mix as a starting point. Put bluntly, it takes the likes of Peter Cobbin a lot longer to produce a true, discrete-channel 5.1 surround mix (and therefore costs the record company a lot more) than it does to pay Andrew Walter to create an upmix from the stereo version in a few hours.”

(Robjohns 2002)

If the likes of big pop stars such as Emma Bunton’s record companies (Virgin Records) choose to use upmixing techniques to release a surround version of a single, instead of properly recording it in surround, then this must be a very viable technique to produce 5.1 Audio. However little has been done on the comparison between upmixing from stereo and ‘properly’ recording in 5.1. This is the purpose of the proposed study, to compare both techniques and find out the general public’s preference, to allow record companies such as Emma bunton’s to see whether the material should be recorded ‘properly’ in 5.1 surround or whether the same listener experience can be created utilizing upmixing techniques.

Robjohns Hugh. 2001-2002.

You Are Surrounded: Surround Sound Explained - Part 1-9

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