Date:         Mon, 10 Nov 2003 15:08:38 -0800
Reply-To:     Association for Recorded Sound Discussion List
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Sender:       Association for Recorded Sound Discussion List
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From:         Mike Richter <[log in to unmask]>
Subject:      Re: 74 vs 80 minute CDRs
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At 12:30 PM 11/10/2003 -0800, David Seubert wrote:
>I'd like to get opinions from people on the list on 74 vs. 80 minute CDRs.
>We are finding it increasingly difficult to find 74 minute CDs. Last time I
>needed CDRs I found that Taiyo-Yuden now only makes 80 minute discs and in
>fact very few companies make 74 minute CDRs. We burn on two brands, Mitsui
>and a second brand. The latest batch we bought were Verbatim, which we are
>discovering have very high error rates on our setup when burned above 12x
>(though they are fine below 12x).
>
>I've always avoided 80 minute discs because my understanding is that Red
>Book CDs are 74 minutes long and 80 minute CDs are not Red Book standard.
>Is this correct? Is there another standard for 80 minute CDs, or is the
>design of 80 minute discs subject to the whims of the manufacturer? Is
>there actually any evidence of greater incompatibility with 80 minute
>discs? I don't want to switch to 80 min, but it looks like the market may
>be heading that way.

Questions on media should be researched at Media Sciences,
http://www.mscience.com/ if they do not go to brand names. Jerry is
extremely knowledgable but his company sells analyses to those with
specific needs and those results are private between the company and the
buyer. That can be quite frustrating as when a few months ago he reported
that he had finally found a combination of drive and medium which truly met
the specs at 16x - but was not free to name them.

80-minute media are outside the intent of the spec, though there is
argument that they are technically within it. The error rates are higher
particularly on the outer part of the disc. I find that even with tests in
my computer, the difference is detectable except when the C1 and C2 error
rates are zero. Media Sciences goes far deeper, of course; you may find his
notes on the limitations of BLER of particular interest. I have a BLER
tester and planned to set it up until he discouraged me. (It's still on my
to-do list when I have spare time. At the moment, that seems likely to be
the lifetime after next. <G>)


Mike
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http://www.mrichter.com/