C2 errors on all discs


I’ve recently discovered Nero CD-DVD Speed and after testing several of my CDRs, I’m a bit concerned that there may be a problem with my CD drive.

I’ve tested several CDRs from different manufacturers, different burn speeds, burned on different machines using different software. However, they all show a C2 spike in the same place (about 80% of the way through the disc). This also happens to be the same place that the drive reaches about x44 speed. When I limit the reading speed to x40, the C2 errors don’t appear. But surely if it’s a x48 speed drive, it should be happy to read close to this speed without showing errors. Can anyone shed any light on this? Is my CD drive about to become a coaster-maker?

For info, my system is:
Pentium IV 2.4 Ghz
80GB Seagate hard drive
Windows XP


I should also mention that I’m referring to CDs containing data (CD-ROM) as opposed to audio CDs.

Also, when I use Scandisk, the last little square is usually red, although the files themselves are OK. I’m not sure if this is connected to the C2 problem.

Maybe the red square at the end is because the disc wasn’t closed or finalized, or whatever it’s called?

My Cdspeed help doesn’t work. Does yours?

In a perfect world, you should not see any C2 on any disc at any read speed. The 48125S can be a little twitchy at max speed scanning, but still a high quality disc should not show C2. If you want to do a little comparison, use a FULL manufactured CD-ROM disc and run the same test, then compare. A well-burned CDR should look better than the average manufactured disc.

Around here, the standard for CDR scanning has always been max speed. But if you get a good scan at 40x, it’s at least a readable disc. C1 levels should be correspondingly low, and anything over 100 max should be viewed with suspicion. Although, I have seen CDR’s with C1 over 2000 that can still be read very well and have no C2.

Hi Strings, welcome to CDFreaks! :slight_smile:

Are you using a recent version of Nero CD-DVD Speed? The latest version is

I have seen the problem with the last square in ScanDisc being marked red incorrectly on earlier versions of CDSpeed.

Wasn’t this issue related to TAO burning?
Please don’t forget to burn Disc-at-once and with NO MULTISESSION. :iagree:

I don’t know. It’s only a vague memory by now, but I don’t recall seeing this problem with CDSpeed 4.x. I burn almost all my discs as DAO, so you could be right.

Most of my old CD-RW archives show a couple of red squares at the end of the burn. That’s when I check the circle for “Read test”. They don’t show when I check “C1/C2” test. I believe it is always the case when the disc wasn’t closed. These are good burns too, passing all other tests with flying colors.

This is true no matter what version of CDspeed I use, including the latest.

However I tried to replicate this by burning a CD with my new DVD burner, and I can’t. No red squares. I’m thinking it was caused by my old CD burners. Or maybe it was caused by an old version of Nero.