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Topic: CRC mismatches on same tracks across multiple copies of same new disc? (Read 2633 times) previous topic - next topic
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CRC mismatches on same tracks across multiple copies of same new disc?

Hello, this seemed like the best place to ask this:

I've got a copy of Numero Group's Unwound box set What Was Wound--and on a few discs I consistently get CRC mismatches when doing Test+Copy.

This seems extremely odd to me, especially when it seems to center on particular tracks. For example, Disc 5 I've got three copies of at this point (they sent a single replacement disc, followed by a second complete set) and tracks 12-18 always mismatch.

For example, this is track 12 over multiple attempts [unfortunately, I'm not completely sure at what point I shift between each of three copies):

Code: [Select]
     Peak level 98.8 %
     Extraction speed 27.3 X
     Test CRC 173B9AC4
     Copy CRC 9325E0F6
     Track not present in AccurateRip database
     Copy OK

---2nd physical copy of disc---

     Peak level 98.8 %
     Extraction speed 26.3 X
     Test CRC 1224A8DC
     Copy CRC 173B9AC4
     Track not present in AccurateRip database
     Copy OK

     Peak level 98.8 %
     Extraction speed 15.9 X
     Test CRC 58D369A9
     Copy CRC B9DA8865
     Track not present in AccurateRip database
     Copy OK

     Peak level 98.8 %
     Extraction speed 27.3 X
     Test CRC 9325E0F6
     Copy CRC FE4EB678
     Track not present in AccurateRip database
     Copy OK

---3rd physical copy of disc---

     Peak level 98.8 %
     Extraction speed 27.3 X
     Test CRC 5E1FED87
     Copy CRC BCC5BA7D
     Track not present in AccurateRip database
     Copy OK

     Timing problem 0:02:34

     Peak level 98.8 %
     Extraction speed 15.5 X
     Test CRC 182DD20D
     Copy CRC 0A6F8CB4
     Track not present in AccurateRip database
     Copy finished

That timing error that appears on the 3rd copy was completely new--hadn't seen any errors except the mismatches on the set until this one.

A few CRCs repeat (albeit never in pairs). This particular disc actually skips about 33-50% of the time, while the other discs in the set with CRC mismatches (4/11 discs) I don't think I've noticed audible issues with when playing the original disc, and I mostly notice skips in fewer places than I'm seeing mismatches. A few odd tracks outside the consistently bad ones some times come out consistent across reads, but some never come out the same.

I've ripped a good few hundred+ discs in this drive (LG GH24NSB0) and previously never had issues, outside of the odd used/OOP disc that either needed a cleaning or was truly hosed, nor had any issues with discs I've picked up after these.

Am I crazy, or does this indicate a manufacturing issue?

Certainly the skips (and at least one I hear consistently at roughly the same position on the same track of the same disc in all 3 copies I have of it--~2:20-2:30 on D5, T13) lean me that way, but I've just never seen this many errors, especially (semi-)consistently. And it's also a bit weird to me that the spot I just referenced sometimes plays fine on a variety of CD players (home and car). Sometimes it loops over a single moment in the "classic skip" fashion, and sometimes loops over 15-30s. It often seems that if I skip to the problem track, it plays fine, but if I let it play up to the track I get problems (but neither of those is 100% consistent, just a sort of overarching trend).


Re: CRC mismatches on same tracks across multiple copies of same new disc?

Reply #2
Could very well be. I would have tried a different drive, if you cannot ask for a replacement.

I've had a skip at the same spot in every stereo I have (~2:29 on that track), on all three copies, so I did at least have a different set of hardware (not clear or consistent skipping on other mismatched tracks, though). After two replacements, I felt pretty confident, but they said they've had no other complaints (they're being quite good to me despite that--a replacement disc, then a replacement set, now willing to accept a return after quite some time)

Don't have another SATA drive handy, though I certainly considered that as an option to confirm.

Re: CRC mismatches on same tracks across multiple copies of same new disc?

Reply #3
Ah, you had multiple copies, even. Sorry, read a bit too quickly (... box set ... multiple discs ... multiple copies ... oops).

Manufactoring error, I'd say - but that is not to say that it will skip in every CD player although you tried a few.
(Is the disc in the CUETools database?)