Error Correction Tests

Many are the times in our daily computerized life we face scratched and defected CDs. There are drives with stronger error correction able to correct read errors coming even from big scratches and other trammels on the CD surface. One way to test a drive's reading effectiveness is the Almedio's ABEX testing system.

- ABEX TCD-721R

Errors total	Num: 176590116
Errors (Loudness) dB(A)	Num: 831475	Avg: -27.2 dB(A)	Max: -5.4 dB(A)
Error Muting Samples	Num: 376351	Avg: 1.2 Samples	Max: 3578 Samples
Skips Samples	Num: 52	Avg: 757.8 Samples	Max: 2939 Samples
Total Test Result	48.9 points (out of 100.0 maximum)

Unfortunately the drive's performance in this test was disappointing. The amount of errors during the reading process was high and the error loudness maximum level was -5.4dB, which is very high. The drive also skipped 52 samples after being unable to read some heavily defected areas.

- ABEX TCD-726

Errors total	Num: 11145
Errors (Loudness) dB(A)	Num: 48	Avg: -174 dB(A)	Max: -174 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	100 points (out of 100.0 maximum)

The Abex TCD-726 test disc is generally easier to be read. So don't let the above flawless graph to fool you. But to be realistic the drive's behavior with the light scratches of the ABEX TCD-726 test CD was perfect. The problem occurs with scratches exceeding 1.500mm, as the ABEX TCD-721R test shows.

- CD-Check Audio Test Disc

Knowing how irritating it is to experience lapses when listening to music, the CDRinfo research team has decided to use a test to check the Audio quality and correspondence. CD-Check Test Disc is the 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 is.

Error Level	1	2	3	4	5
Lite On SOHC-5232K	5/5	5/5	5/5	5/5	0/5

The drive successfully passed all the first 4 check levels, but it didn't manage to play the 5th track without lapses. The 5th track is very difficult to be read because it has a scratch of 1.500 mm size. Most drives fail to play the last track flawlessly, so we can say that the drive's correcting capability is normal.

- Summary

Test Disc	Reading Speed	Score
ABEX TCD-721R	Max	48.9
ABEX TCD-726		100
Average Score		74.5

Summarizing we can say that the drive could be better at correcting badly scratched discs, while other defects can be corrected adequately.The average outcome for the drive is 74.5 points.