C2 Spikes in Nero CD Speed

[djm52]

I have started seeing isolated spikes in the Nero Disc Quality plots. The C2 spikes are usually about 2000 high. Sometimes they are repeatable, but sometimes a second pass will be clean, or will show a spike in a completely different location, as in the first two figures at:

http://home.nyc.rr.com/dmcguire/_nero.htm

I see this on discs I burn, and on discs given to me by friends. I see it on cheap blanks, and also on good ones - the examples are from a Taiyo Yuden burned by a friend.

It almost looks like the spikes are in playback, or perhaps it's just a problem with the NEC drive I use for these tests. My Lite-On drive doesn't show the spikes (see third plot , on same Taiyo Yuden). But the Lite-On is generally *much* better at error recovery than the NEC, and if I want to simulate what a typical player (car, discman, etc) will see, I try to use the NEC to run these tests.

Are these spikes real, or are they phantoms? I have listened to a few of these, on a boombox or on the NEC, and I don't hear any problem.

Thanks in advance.

[MonsterMan]

I've never trusted NEC's for error testing.

The Lite-On drives are great for CD testing, not so great for DVD testing.

Benq's are great testers, too.

Since the spike only shows on the NEC, don't worry about it. I had an NEC that produced massive error spikes mid-burn on DVDs; but those showed up on the BenQ scans, too...

[RJW]

C2-errors are not actually there on the media. It is the drive that sees something is wrong and reports a error.

It looks like the NEC for some reason (maybe a PUH (Pick Up Head) slip or something internally) reports a error. However these problems are non media related. It's pure a error from the drive.
Now some drives have more of these problems as others.

In short: The disc's are fine.