CD 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: 431363124
Errors (Loudness) dB(A)	Num: 2069442	Avg: -31.6 dB(A)	Max: -7.2 dB(A)
Error Muting Samples	Num: 843236	Avg: 2.7 Samples	Max: 1218 Samples
Skips Samples	Num: 0	Avg: 0.0 Samples	Max: 0 Samples
Total Test Result	67.4 points (out of 100.0 maximum)
C2 Accuracy	74.9 % (out of 100.0% maximum)

The Plextor PX-712A performed very badly with the ABEX TCD-721R. The drive from the start began producing high spikes and the total score is rather disspointing. This is very strange since its predesessor performed much better. The C2 accuracy score is also rather low (74.9%).

- ABEX TCD-726

Errors total	Num: 431673801
Errors (Loudness) dB(A)	Num: 2069398	Avg: -31.5 dB(A)	Max: -7.3 dB(A)
Error Muting Samples	Num: 843388	Avg: 2.7 Samples	Max: 1274 Samples
Skips Samples	Num: 1	Avg: 550 Samples	Max: 550 Samples
Total Test Result	54.7 points (out of 100.0 maximum)
C2 Accuracy	74.9 % (out of 100.0% maximum)

Again the PX-712A didn't produce good results with the ABEX TCD-726 disc at full speed.

- 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	3/5	0/5

Plextor PX-712A passed the three 3 Check Levels of the test. The performance reveals average sound reproduction and error correction. The fifth level includes an error size of 1.500mm, and the drive returned many audible clicks.

- Conclusion

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	67.4
ABEX TCD-726		74.9
Average Score		71.15

Combining the two scores from the tests we get an average total score of 71.15 points out of 100. This performance was rather dissapointing for a Plextor drive and probably this should be improved with a new firmware revision.