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: 1327724
Errors (Loudness) dB(A)	Num: 58521	Avg: -73.0 dB(A)	Max: -35.0 dB(A)
Error Muting Samples	Num: 4183	Avg: 1.0 Samples	Max: 11 Samples
Skips Samples	Num: 0	Avg: 0.0 Samples	Max: 0 Samples
Total Test Result	76.4 points (out of 100.0 maximum)

The performance with this disc is good. The total error count is about average while the maximum loudness error level is quite good and there were no skipped samples. The total score is very good.

- ABEX TCD-726

Errors total	Num: 25523587
Errors (Loudness) dB(A)	Num: 119814	Avg: 0 dB(A)	Max: -5.7 dB(A)
Error Muting Samples	Num: 54509	Avg: 110.9 Samples	Max: 3584 Samples
Skips Samples	Num: 2	Avg: 1596 Samples	Max: 1596 Samples
Total Test Result	53.4 points (out of 100.0 maximum)

The Abex TCD-726 test disc is a usually a simple case for error correction. The BTC drive however, performed poorly. The total error count is high, while there are two skipped samples and many muted samples. The total score of 53.4 out of 100 is not acceptable.

- 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
BTC DRW 1108IM	5/5	5/5	5/5	3/5	0/5

The drive performed well. It managed to playback 5 out of attempts for three of the five levels. The fourth level sounded good for three of the five attempts and the fifth level did not play well at all. The attempt can be considered slightly better than average as most drives manage to play up to the fourth level, with some exceptions at last but fail all attempts with the fifth level, which is difficult for the majority of the drives.

- Summary

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	76.4
ABEX TCD-726		53.4
Average Score		64.9

The final average score for the drive is quite low, and this is due to its poor showing with the ABEX TCD-726 disc where the drive scored 53.4, where most other drives manage close to 100.