111^th AES Convention
Monday

  During the AES show there were various seminars and technical papers presented. Many of them concerned the technicalities in recording and reproduction of music while others concerned room acoustics. Still others covered the use of vintage equipment while, of course, lectures on proper mixing/mastering of music were well attended. Because we here at Enjoy the Music.com deal mainly in high-end audio reproduction, one of the highlights was a seminar titled "Myths in Audio".

Chaired by none other than Professor Malcolm O. J. Hawksford (seen above) from the University of Essex in Colchester UK, other panelists included:

James Angus (University of Salford, UK)

David Chesky (Chesky Records New York City)

Stanley P. Lipshitz ( University of Waterloo)

Derk Reefman

What makes this session truly interesting is the fact of DVD-Audio (multi-bit PCM) versus SACD (1-bit DSD) and the seemingly never ending debates between the two formats in various venues. Couple that with the true potential of the ultimate sound quality in performance capabilities within each format... and who truly "wins". Not necessarily the format winning consumer dollars, but in sound quality and capabilities.

One panelist feels that 1-bit technology is not sufficient. He also informed us that 96-kHz is high enough a sampling rate and that anything higher is simply not needed. The debate concerning DSD's (SACD) linearity is questionable at best, not capable of true linearity (at worst). Below is a photo from one of the panelist's presentation myths concerning 1-bit DSD systems:

And now the argument for multi-bit PCM as seen in the below photo from one of the panelist's presentation:

While some may not agree with DVD-Audio's Meridian Lossless Packet (MLP) for compression, please remember that SACD employs lossless compression of 2.7 for classical music and 2.5 compression ratio for pop music. Lossless compression in both formats is needed due to the 5" disc's limited data storage capability.

Stanley Lipshitz seems to feel that 1-bit systems can not inherently be linear. While dither can help aid the linerazition, there is still noise modulation in the signal. As a side note, the noise shaping that DSD (SACD) uses includes a signal feedback circuit that assists with the dithering of the signal. A multi-bit system, such as DVD-Audio's PCM, eliminates such problems. In fact we (the audience) were informed that about 115dB of noise is in DSD due to noise shaping within the DSD system. While most of the noise is above the audio band, this noise shaping is necessary in DSD to achieve low distortion the audio band according to Lipshitz.

To throw more confusion into the mix and further muddy the waters of present day DVD-Audio and SACD standards, David Chesky feels that 5.1 may not be the answer to surround. Chesky music has released both SACD and DVD-Audio music discs so they have no axe to grind nor work for a company using one format over the other. David feels that music is an art more than a science. The goal of a system is to allow the listener to be transformed to the music venue. David said he is nervous about both formats due to the "apathetic age of sound" by the public where people feel that CD sound is fine.... let alone MP3. It is "ludicrous" as he knows people are spending more and more money to make worse sound MP3 music available.

The "ascetics of sound" was at a high point in the 1960's as people were obsessed with recreating good sound. Today it seems the dynamic range in music is squashed (compressed), most of today's recordings have distortion, and many other situations where the quality of sound seems to not be cared for by the general public. Music is not just for entertainment, but also for documentation... capturing a moment in time.

David Chesky feels that two-channel listening is like looking through a window while multi-channel is like being in the actual space (for acoustic music). David is not thrilled with 5.1 due to music being a three dimensional media. To David Chesky, 5.1 is like glorified quad recordings. What Chesky is doing is six full-range channels. Two front, two rear and two side channels. The height of the sound is accounted for by putting the side loudspeakers a few feet above the front/rear plane. While some people may be annoyed by what Chesky is doing, they have different recording (channel quantity) on their discs to accommodate accordingly.

Chesky Record's newest release is in Ambiosonics... six channels worth! CD is a waste of time according to David Chesky and we need to get away from it. High definition DVD may eventually be over ten channels of audio.

This session ended with some questions and comments from the audience. Various comments by Tomlinson Holman were made, but he admitted his system is not for music. In this reporter's opinion that is good as THX surround sound leaves a quite bit to be desired. This may be due to the extreme amount of equalization coupled with the horrible state of film sound tracks and overdubbing in THX recordings. There was another seminar that was on the same lines as the above seminar. This other three section session was titled "Towards a Better Understanding of 1-Bit Sigma-Delta Modulators - Part 2", "Effective Dither in High-Order Sigma-Delta Modulators" and "Non-Invasive Identification of Audio Content for High-Resolution Applications".

While the previously covered seminar was very professional with versions panelists debating facts, this session had some real verbal fireworks and excitement! The debate rages on concerning non-linearitys of 1-bit systems like that used by SACD's DSD process. Imagine well-established Professors from the UK battling it out... with a Canadian thrown in to the mix for good effect. James A.S. Angus was particularity thrown against the mast as he defended the Sony/Philips DSD 1-bit system. While not quite like a WWF match where three professors (in the audience) were against one (Mr. Angus), it was indeed good to see some true debating going on.

Professor Malcolm O.J. Hawksford rounded out the situation by discussing the effects of watermarking. Malcolm discussed how a reference signal (source) and the target signal (a copy of the original) can be measured and correlated. All in all this last seminar i attended was a nice way to round out the usual mainstream propaganda handed down by manufactures to the press.

This concludes our virtually live 111^th AES show coverage. Hope you enjoyed it. Of course in the end what really matters is that you...

     Enjoy the Music,

    Steven R. Rochlin

Click here for the main AES 2001 report page.