About Dolby and Beta SP

Sony’s Beta video recording format became a staple of professional video production. The first Beta professional decks evolved into Beta SP, a professional video recording production format that ultimately became ubiquitous.

And here’s where it gets interesting in terms of Dolby. According to Hilson, Beta SP was designed with noise reduction in mind. Dolby C was specified as part of the default audio capability. The cassette shells for Beta SP tapes were fitted with a notch in the shell which activates Dolby C as the default operating condition for Beta SP. Earlier shells for Beta Pro don’t have such a notch – when they are played back on a Beta SP deck, Dolby C has to be selected manually. The only time Dolby is not to be used is when playing back un-encoded Beta Pro tapes. Naturally, the non-Dolby performance of the Beta SP deck was not considered to be important, and was in fact marginal, according to Hilson.

So, far all our complaining, it turns out that Dolby C is both integral AND essential to the Beta SP format, which probably wouldn’t have been acceptable without it. Not an option, but a necessity. Hmmm. Puts things in a different light, as they say.

Audio Education: The Dolby Website

The most important part of this has to do with knowledge. Dolby has made a point of developing a substantial website, (Dolby.com) that includes a comprehensive history of the company and extremely detailed presentations of all of their technology, many available as .pdf files.

Jim and Adam make the entirely reasonable case that it is incumbent upon the users of the technology to familiarize themselves with the technology. This is particularly true in a case such as the Beta SP/Dolby C case, where the format is essentially an integrated one.

For starters, I recommend that a cursory reading of the Dolby history (http://www.dolby.com/about/) is useful. Then go to the noise reduction pages (http://www.dolby.com/technicallibrary.aspx?id=306) and wade through Ken Gundry’s series of pieces on the principles of noise reduction, AKA “Ken’s Corner.” You may learn far more than you want to know about noise reduction (Ken does go on a little), but this is a really useful primer for a difficult subject. It will be especially illuminating for those of us who got into this business after digital audio replaced analog audio for most recording and production purposes, say ten years ago. Then, for more specifics, read http://dolby.com/cassette/bcsnr/ [try here], which includes detailed discussions of Dolby B, C and S noise reduction systems.

There’s lots more. Of specific current interest to this readership is a page devoted to TV audio, (http://dolby.com/tvaudio/). It focuses, of course, on surround production, Dolby Digital and the like, and it is specifically oriented to the readers of TV Technology.

If you’re like me, you’ll find a real treasure trove of trivia and not-so-trivia throughout the Dolby site. I particularly like the Dolby Guide to Metadata, which is the basis of one of my next articles.

What does it all mean? Dolby’s technology is powerful and effective stuff. It is also not for dummies, a thought that illuminates a more basic verity of audio, which is: it’s hard to do audio, and it’s really hard to do it well. As Jim Hilson put it, in our conversation, “There’s a sense among some TV engineers that, if the meters are moving the sound must be OK. That simply isn’t good enough.”

I agree.

Thanks for listening.

Dave Moulton is trying to get his meters to move. You can complain to him about anything at davemoulton.com.

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