Someone on the audioreview.com General board wrote about a paper presented at the AES convention in September in LA entitled, "Why Professional 1-Bit Sigma-Delta Conversion is a Bad Idea". The authors of the paper are Stanley P. Lipshitz and John Vanderkooy of the Audio Research Group at the University of Waterloo. This paper is available as a PDF, and someone posted it on their Yahoo! home page. See the link below to get to the PDF. When you get to the Yahoo! page, click on "My Folder". Then, click on "00105.pdf" to open the file (you need Acrobat Reader to view it). The abstract of the paper reads:
"Single-state, 1-bit sigma-delta converters are in principle unperfectible. We prove this fact. The reason, simply stated, is that, when properly dithered, they are in constant overload. The consequence is that distortion, limit cycles, instability, and noise modulation can never be totally avoided. Recording, editing, or storage systems based upon single-stage, 1-bit sigma-delta conversion, and in particular professional systems using this type of conversion, are thus a bad idea. In contrast, multi-bit sigma-delta converters which output linear PCM code (and here, multi-bit refers to five or so bits in the converter) are in principle infinitely perfectible. They can be properly dithered so as to guarantee the absence of all distortion, limit cycles, and noise reduction. The audio industry is making a tragic mistake if it adopts 1-bit sigma-delta conversion as an archival format to replace multi-bit, linear PCM."
Take a look at the paper and offer comments. Is this reading like what appeared in Stereophile a month ago? By the way, here is a link to the thread on audioreview.com if you want to post feedback there too:
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Topic - Anyone see this paper: "Why Professional 1-Bit Sigma-Delta Conversion is a Bad Idea"? (read on) - 9fold 08:09:57 12/15/00 (2)
- Re: Anyone see this paper: "Why Professional 1-Bit Sigma-Delta Conversion is a Bad Idea"? (read on) - George Sallit 10:37:49 12/15/00 (0)
- Re: Anyone see this paper: "Why Professional 1-Bit Sigma-Delta Conversion is a Bad Idea"? (read on) - Mike Bates 09:51:49 12/15/00 (0)