Digital Audio - Mr. Datta enlightens seasoned recordists about a whole new realm of audio

JAYANT DATTA is a practicing digital audio engineer, currently based in the US. He is a co-founder of Discrete Laboratories, which allows him to serve as a digital audio consultant to high-end audio and video manufacturers by providing unique, customized and innovative hardware and software solutions. He is also an adjunct faculty in Electrical Engineering at Syracuse University, where he teaches Digital Audio Signal Processing

His audio experience covers a wide area – professional, broadcasting, DSP chip design, consumer, prosumer, and digital cinema. Briefly, he has spent time in a recording studio environment; designed the first digital mixing console for on-air (broadcast) applications [which won awards at the National Association of Broadcasters (NAB) Convention]; developed numerous audio processing algorithms for real-time digital signal processing (DSP) solutions. More recently, Jayant left the Digital Audio Group within Motorola to start his own company. For the last few years he has been concentrating on multi-channel audio applications.

Jayant has authored numerous technical papers and articles, including a few at AES Conventions. He regularly chairs digital audio sessions at international conferences and is a member of the AES Technical Committee on Signal Processing. He is also active within the Institute of Electrical and Electronic Engineers (IEEE), where he serves in various capacities.

In his talk, Jayant introduced the basics of digital audio, examined the differences between analog and digital systems, and discussed digital mixing console design. 

He touched upon several interesting topics like sample rates, sample rate conversions, DSP, surround formats, converters etc. Basically refreshing his audience on Digital Audio concepts. 

It was interesting to learn how recording at low levels in the digital realm actually affects the recording quality, as it does not utilize all the bits available.

It was also argued whether we need as much bit rate and sampling frequency we are heading towards to – SACD with its astonishing 2.8Megs. 

He did speak about sample rate conversions, how its better to convert down to exactly half the current rate rather than any rate. For eg. 96k should be down converted to 48k for best results. Also argued were the varying results when conversion took place either real time or not. 

When he spoke to us about his specialty, DSP, he did mention how some silicon manufacturers program their chips in different ways than others whereby actually having much better performance, than chips which have stunning printed specifications to their credit. 

Bollywood, the largest film industry, was still naïve on exact specifications of the available surround formats, which, thanks to Mr.Datta, is well understood by us now. 

There was argument on why there is not a set reference standard between the digital and analog levels, since broadcasters have stringent rules, that if met in the analog format, don’t show the same results in Digital and vice-versa, which proves a big problem for the studios.

Also, questioned by a member was what to look for in the spec sheet of a AD/DA manufacturer before deciding to purchase it. As he was going through them, the particular member in question, presented a spec sheet of a particular piece which listed almost nothing worthwhile, but yet really expensive. He cited the example of a rolls-royce, where the buyer is not aware about the engine power, but yet spends a fortune on that luxury. 

The turn out was overwhelming, even though it was a Sunday.

The members thanked Mr.Ashok Honda for providing us his studio as the venue for the meet.