Error Correction Tests

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

- ABEX TCD-721R

Errors total	Num: 844191
Errors (Loudness) dB(A)	Num: 47605	Avg: -74.0 dB(A)	Max: -36.0 dB(A)
Error Muting Samples	Num: 2697	Avg: 1.0 Samples	Max: 11 Samples
Skips Samples	Num: 0	Avg: 0 Samples	Max: 0 Samples
Total Test Result	77 points (out of 100.0 maximum)

The drive had very good behaviour with the ABEX TCD-721R test disc, giving a very low count on the number of errors at an average of -74 dB. Notice that the maximum value was at -36 dB. The muting samples were 2697 while none were skipped. The score of 77 points is a good one.

- ABEX TCD-726

Errors total	Num: 37
Errors (Loudness) dB(A)	Num: 4	Avg: -73.6 dB(A)	Max: -58.4 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	94.3 points (out of 100.0 maximum)

The Abex TCD-726 test disc is much easier for drives in general to read, and as such, the BTC DRW1008IM drive corrected almost all errors, only 4 were reported. The score in this test is 94.3 points out of 100, which is very 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 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 drive.

Error Level	1	2	3	4	5
BTC DRW1008IM	5/5	5/5	5/5	5/5	0/5

The drive succesfully passed the first 4 check levels for this test. The 5th tracks produced a constant noise in the background. Notice that the 5th check level, which has a scratch a size of 1.500 mm, is difficult to read with most drives. The fact that the drive managed to read perfectly up to the fourth level is quite good, and we can comfortably say that the drive is capable of reading defective discs.

- Summary

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	77
ABEX TCD-726		94.3
Average Score		85.7

Combining the two scores from the ABEX tests gives an average total score of 85.7 points out of 100. This is a very good overall score.