Error Correction Tests

In the following tests we check the drive's behavior when reading scratched / defective audio discs. The test discs used were the ABEX series from ALMEDIO.

- ABEX TCD-721R

Errors total	Num: 124945527
Errors (Loudness) dB(A)	Num: 584663	Avg: -25.2 dB(A)	Max: -4.8 dB(A)
Error Muting Samples	Num: 22659	Avg: 3367.2 Samples	Max: 3584 Samples
Skips Samples	Num: 8	Avg: 2939.0 Samples	Max: 2939 Samples
Total Test Result	45.2 points (out of 100.0 maximum)

This is generally a difficult disc for most drives to read correctly. The drive was extremely slow when reading the test disc and the scratched areas were extremely hard to read. After some hours of ripping and analysing, the drive came up with a poor performance. The situation was the same in the case of the previous Optorite model, the DD0401. The number of total errors is on the high side, asa is the maximum error level at -4.8 dB(A).

- ABEX TCD-726

Errors total	Num: 11145
Errors (Loudness) dB(A)	Num: 66	Avg: -38.7 dB(A)	Max: -23.3 dB(A)
Error Muting Samples	Num: 26	Avg:1.0 Samples	Max: 1 Samples
Skips Samples	Num:2	Avg:30.0 Samples	Max: 30 Samples
Total Test Result	80.7 points (out of 100.0 maximum)

The results of the Optorite with the 726 Abex test disc are not the best we have seen but they are at an acceptable level. The software awards the drive with 80.7 points out 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 more difficult tests. These tracks are referred to as Check Level-1 through Check Level-5.

The tracks are reproduced (played) through different software multimedia players (i.e. Winamp, PowerDVD, 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 drive.

Error Level	1	2	3	4	5
Optorite DD0405	5/5	5/5	5/5	5/5	5/5

Although we didn't expect Optorite to perform well on the Audio test Disc because of its performance with the previous CD error correction tests, on this test the results were perfect. The drive managed to playback all levels of the disc succesfully. There were no audioable clicks, muted or skipped areas. We should also mention that most drives do not manage to reach the fifth check level. Error concealment circuitry works very well in this case.

- Summary

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	45.2
ABEX TCD-726		90.1
Average Score		67.65

The average score for the Abex tests is 67.65 points for the Optorite DD0405. This is not among the best scores we have recorded, and indicates the drive has problems and offers low performance with scratched media (TCD-721R). With less seriously defective discs, the drive is very strong.