BLER (Block Error Rate) is defined as the number of data blocks per second that contain detectable errors, at the input of the C1 decoder. Since this is the most general measurement of the quality of a disc, you will find BLER graphs for all media tested below. If you click on the images you can see a more detailed table, indicating error levels.

The Red Book specification (IEC 908) calls for a maximum BLER of 220 per second averaged over ten seconds. Discs with higher BLER are likely to produce uncorrectable errors. Al low BLER shows that the system as a whole is performing well, and the pit geometry is good. However, BLER only tells us how many errors were generated per second, and it does not tell us anything about the severity of those errors.

Memorex CD-R 52X

Click for the full graph

Click for the full graph

Memorex Pro Gold CD-R 52X

Click for the full graph

Click for the full graph

Both media reported a difference in error rates, more so with the CD-R 52X media, especially at the outer edge of the media surface (from the 70 minute mark onwards). In case of the Pro Gold disc there is a slight difference, at the end of the reading area, while the spike at the beginning might be a quirk of the software, with the same spike being produced with the CD-R 52X disc in its initial measurement but wasn't present in the after measurement.