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: 1491423
Errors (Loudness) dB(A)	Num: 165000	Avg: -79.5 dB(A)	Max:-35.5 dB(A)
Error Muting Samples	Num: 5204	Avg: 1.0 Samples	Max: 12 Samples
Skips Samples	Num: 0	Avg: 0 Samples	Max: 0 Samples
Total Test Result	75.0 points (out of 100.0 maximum)

When NU finished the Abex 721R error correction test, EAC software award it with a total score of 75.0 points out of 100.0 maximum. The score can be considered as satisfactory. The total error count at 1,491,423 is quite high, as is the loudness error count, but the loudness level (-35.5 dB(A)) is quite low and there were no skipped samples.

- ABEX TCD-726

 

 

Errors total	Num: 141
Errors (Loudness) dB(A)	Num: 391	Avg: -84.0 dB(A)	Max: -60.5 dB(A)
Error Muting Samples	Num: 0	Avg: 0 Samples	Max: 0 Samples
Skips Samples	Num: 0	Avg: 0 Samples	Max: 0 Samples
Total Test Result	89.6 points (out of 100.0 maximum)

The 726 test disc is a much easier disc for most drives to read than the previous 721R test disc. The total score for the drive, 89.6 points out of 100.0 maximum, is not as high as we normally see, even for an average drive.

- 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 reading music abilities and reproduce it completely. Five tracks on the disc contain a progressively difficult sequence. These tracks are referred to as Check Level-1 through Check Level-5.

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

Error Level	1	2	3	4	5
NU DBW-521	5/5	5/5	5/5	1/5	0/5

The NU drive performed slightly better than average. The drive managed to playback the first three levels without problems as is the case with most drives. With the fourth track, the drive managed one out of five plays and none for the fifth track. Only the better drives manage to play the fourth or fifth tracks.

- Summary

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	75.0
ABEX TCD-726		89.6
Average Score		82.30

The overall performance of the NU combo DBW-521 in the CD error correction tests can be considered as acceptable. The average score for the drive was 82.30.