The BLER (Block error rate) is the number of errors by second reported by a CD player.

This value represents the quality of your recorded disc and depends of several parameters such as the CD recorder, choice of media and recording speed.

To reduce the BLER on your CD you can:

1) Try different recording speeds. Don't believe the “urban legend” about low speed recording. Current recorders are optimized for high speed and "may" give best results at half the maximum write speed.*
2) Be aware of CD Writer’s aging characteristics, particularly the laser. Monitor BLER regularly and if a rise in error rate is noticed it may be time to change the writer.
3) Experiment with several types of media. The quality of the disc is the first source of BLER. Current CDs are optimized for high speed, but some media dedicated to audio mastering may be found that are specially built for low speed writing (A compromise may have to be found here, to comply with point 1!)
4) Repeat tests regularly, as quality of specific media of a given brand/model/reference can vary over time, from batch to batch.
5) As new media may require new firmware, check very regularly (once a week or at least once a month!) if your writer's firmware is up to date, and please at least update a soon as you encounter writing issues.

BLER as well as other quality check tests can be performed with Plextools Professionnal, a software utility that comes bundled and only works with "pro" Optical Recorders such as PX712, PX716, PX755 from Plextor. Plextor Pro Drives are included in all Pyramix Workstations by default as universal CD-R/RW DVD±R/RW. More on Plextools can be found here: http://www.plextools.com/ 

Here you can download a Power Point Show about CD-R Production and Quality:http://www.merging.com/download/CD-R_Production.pps 


Also see this topic for more about write speed: http://forum.merging.com/viewtopic.php?t=1436 


* As service/alignment/maintenance manuals from ALL of the manufacturer of CD writers instruct technicians to align the lasers at "one half of the maximum write speed" error count should be the absolute minimum at that write speed.