Nero CDspeed not scanning for C2 errors?

So I’ve browsed through some guides a few times (including geno888’s popular one), and I don’t think that Nero CD speed is even scanning for C2 errors on my CDs. (I have a graph and results chart below for a scan. Granted it was apparently a pretty good disc, shouldn’t there be some things C2 related on here? And even for poor quality discs that I’ve scanned, I get the same thing. No C2 anything.) Am I right about this? If so, how do I get CDspeed to scan for these errors? Thanks!

A healthy CDR will have no C2 errors at all. Chances are your BenQ is doing exactly what it’s supposed to. :slight_smile:

Put it this way - if you see any C2 errors, then I’d worry :bigsmile:

Additionally, I’ve never seen any reports here of the BenQ you have (which is the same as mine) not reporting C2 errors.

Edit: No doubt Drage will be along with a more technical explanation of the types of C2 error the BenQ reports. Hopefully :wink:

You called? :smiley:

BenQ DW1655/1650/1640/1620 drives report C1 errors (BLER) and C2 failures (E32) when using the normal Disc Quality scanning - this is the most common (but not the most useful) way of reporting C1/C2 in CDSpeed.

BenQ DW1655/1650/1540/1620 drives report all the individual Exy errors when using Advanced Disc Quality scanning, as well as BLER=E11+E21+E31.

Here’s an explanation that I wrote earlier:

There are two layers of error detection and correction on all CD media; these are called C1 and C2. Data CDs also have a third layer of error detection/correction.

There is more than one way to handle C1 and C2 error detection/correction, but a simple and common way is to detect and correct up to two errors per frame in each stage and detect three or more errors:

  • E11: 1 error detected and corrected by C1 layer
  • E21: 2 errors detected and corrected by C1 layer
  • E31: 3 or more errors detected but not corrected by C1 layer

The sum of these (per second) is called the BLock Error Rate: BLER=E11+E21+E31

  • E12: 1 error detected and corrected by C2 layer
  • E22: 2 errors detected and corrected by C2 layer
  • E32: 3 or more errors detected but not corrected by C2 layer

Any E31 is uncorrectable by the C1 layer and will result in the bytes in that frame being redistributed into multiple frames which are passed to the C2 layer.

Any E32 is uncorrectable by the C2 layer and will result in interpolation being used for Audio CDs or will result in third layer error correction being used for Data CDs.

Different drives have different ways of reporting these Exy errors in a Disc Quality scan.

Ok, sounds good. Thanks for the info.!