Error Correction Tests

In the following tests we check the drive's behavior when it comes to reading scratched / defected discs. The test discs we use are the ABEX series from ALMEDIO.

- ABEX TCD-721R

Errors total	Num: 1077734
Errors (Loudness) dB(A)	Num: 52559	Avg: -73.4 dB(A)	Max: -18.2 dB(A)
Error Muting Samples	Num: 4504	Avg: 1.0 Samples	Max: 17 Samples
Skips Samples	Num: 2	Avg: 6.0 Samples	Max: 6 Samples
Total Test Result	71.4 points (out of 100.0 maximum)

Plextor PX-708A performed very well with the ABEX TCD-721R. As you can see from the graph, the majority of the red spikes (error level) reach the -60dB(A) only, and the total average level is -73.4dB(A). Although these errors have nothing to do with any acoustical model, EAC author notes that Error Loudness less than -60dB(A) most often do not produce audible problems to your speakers. However, specific high peaks on the graph (max -18.2 dB(A)) could create some problems, but generally the performance is high considering the severity of the errors on the disc.

The total score for Plextor PX-708A is very good and reaches 71.4 points out of 100.

- ABEX TCD-726

Errors total	Num: 0
Errors (Loudness) dB(A)	Num: 0	Avg: -174.0 dB(A)	Max: -174.0 dB(A)
Error Muting Samples	Num: 0	Avg: 0.0 Samples	Max: 0 Samples
Skips Samples	Num: 0	Avg: 0.0 Samples	Max: 0 Samples
Total Test Result	100 points (out of 100.0 maximum)

In this test. the drive ripped the contents of the ABEX TCD-726 disc at full speed, ignoring all the defected areas on its surface. Comparing the original .wav file (not defected source) with the produced one (after ripping the defected disc) gave no differences, which means that the drive mostly managed to rip the defected disc contents accurately. The score for this performance cannot be different than the absolute score of 100.

- CD-Check Audio Test Disc

The CD-Check Test Disc is a very useful tool for evaluating the Sound Reproduction / Error correction capabilities of a CD player. The disc offers a signal combination with disc error patterns to rate the drive's abilities to read music and reproduce it completely. Five tracks on the disc contain a sequence of progressively difficult tests. These tracks are referred as Check Level-1 through Check Level-5.

The files are reproduced (played) through a software multimedia player (i.e. Windows Media Player). Each level is considered as passed, if the tone coming out from the speakers is smooth, continuous without interruptions, skipping or looping. The higher the Check Level passed, the more reliable the sound reproduction of the tested device.

Error Level	1	2	3	4	5
Plextor PX-708A	5/5	5/5	5/5	5/5	0/5

Plextor PX-708A passed the first 4 Check Levels of the test. The performance reveals very good sound reproduction and error correction. The fifth level includes an error size of 1.500mm, and the drive gave back audible clicks.

- Conclusion

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	71.4
ABEX TCD-726		100
Average Score		85.7

Combining the two scores from the tests we estimate an average total score of 85.7 points out of 100. This is the best score we have ever experienced from a drive. Plextor PX-708A managed to read severely scratched discs with a high accuracy. This is of major importance for users interested in the reliable reproduction of discs , and this drive seems to outperform most other drives on the market today, including some CD-RW recorders.