CD duplication C1, C2 and CU disc errors

Following on from our recent post on CD duplication errors this article looks at the different kinds of disc errors. There are 3 main types of disc error associated with CD audio. These are C1, C2 and CU errors, below is a description and explanation of each error type.

C1 errors are the lowest level bit errors and are usually measured as errors per second. This block error rate or (BLER) is an indication of the quality of the master disc. All masters contain some degree of C1 errors and an average is somewhere between 50 and 200 errors per second. In general the lower the BLER or C1 error rate the better the master is. Although the Philips red book specification allows for up to 220 errors per second most replication plants like to see error rates of below 50 per second.

C2 errors can be caused by poor master CD burning, poor mastering media and also scratches and scuffs to the disc. C2 errors are read errors and not always a physical defect of the disc. One CD player may read more C2 errors than another CD player attempting to read the same disc. Most C2 errors are correctable by the CD player’s error correction, basically this error correction method makes a guess at what values the missing data should be. A certain degree of C2 errors may be acceptable on a master without any audible artefacts, however many replication plants much prefer masters with C2 errors rates of zero.

CU errors are errors that cannot usually be corrected, these uncorrectable errors render a master disc useless and all replication plants will reject a disc that contains CU errors.
The most common uncorrectable error is reffered to as an E32 error and in essence can be thought of as a string of 3 or more C2 errors that cannot be corrected by the CD drives error correction system. Pressing plants mastering software systems such as Eclipse will automatically fail any disc that contains E32 errors.

Leave a Reply

You must be logged in to post a comment.

VIP Offers

Please complete the fields below:



Search Site
Glass Master
Glass Master
Replicate
Replicate
Print
Print
Retail Packaging
Retail Packaging
Duplicate
Duplicate
Card Payment
Card Payment
Google Plus
Like Us
Like Us