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: 3143574
Errors (Loudness) dB(A)	Num: 139529	Avg: -74.3 dB(A)	Max: -18.7 dB(A)
Error Muting Samples	Num: 9506	Avg: 1.0 Samples	Max: 28 Samples
Skips Samples	Num: 12	Avg: 6.0 Samples	Max: 0 Samples
Total Test Result	66.1 points (out of 100.0 maximum)

The performance with this disc was not very good. The total error count was high, and the maximum level of the loudness errors reported will probably mean audible "clicks" in playback. The total score could be better. In addition, many samples were muted.

- ABEX TCD-726

Errors total	Num: 108
Errors (Loudness) dB(A)	Num: 4	Avg: -96.1 dB(A)	Max: -89.2 dB(A)
Error Muting Samples	Num: 2	Avg: 40.0 Samples	Max: 40 Samples
Skips Samples	Num: 0	Avg: 0.0 Samples	Max: 0 Samples
Total Test Result	89.7 points (out of 100.0 maximum)

The Abex TCD-726 test disc is much easier for drives in general to read. That's why TDK performed better than with the previous CD. The total error count was not high, while there no skips and only two mutes. The total score of 89.7 out of 100 is good.

- 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 being reproduced through a software multimedia player (i.e. Windows Media Player). Each level is considered as passed, if the tone 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
TDK 880N	5/5	5/5	0/5	0/5	0/5

The drive once again performed very poorly. It managed to playback only the first two levels out of five. We expected to play successfully at least the first four levels.

- Summary

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	66.1
ABEX TCD-726		89.7
Average Score		77.9

The total score of the drive is not too low. However the CD error correction of the TDK 880N is not something to be proud of.