LiteOn DVD+RW LDW401S - Page 9

CD-R Writing Quality Tests

We used 80min 48x CD-R media by Taiyo Yuden and burned the same AudioCD project at 8x,16x, 24x, 32x and 40x. Below you can see the 3T Pit & Land jitter graphs.

- 3T Pit results

As we can see from the graph above the disc recorded at 8x and 16x gave slightly increased pit jitter in the fist minutes of the disc. In the same time, the rest of the discs gave lower jitter. After the 70min mark of all discs the jitter is increased again to about 38ns and ends with values up to 44ns for the 40x written disc. This is an indication of possible high C1 errors in these areas.

The average 3T Jitter values for all recording speeds are illustrated in the following table.

Although the average pit jitter values of the discs do not exceed the 35ns Red Book limit, we should notice that the lower recording speeds did not gave the best results as we might expect.

- 3T Land results

The Land Jitter values of the same written discs are shown on the graph above. All discs gave back good results, even in their outer addresses . The only exception is the 40x written disc that gave high land jitter after the 70min.

The average 3T Land results are lower over the in the previous measurements of the 3T Pit Jitter.

- 3T Jitter Summary

The average 3T Pit and Land jitter values are below the 35nsec standard for all the recording speeds. However, most of the discs gave high jitter in the outer addresses so the error rate will be possibly higher there.

- CDSpeed CD Quality Check

CDSpeed v2.10 includes a built-in CD quality test, measuring C1 and C2 (only uncorrectable) errors on recorded CD-R media. The utility is available with Plextor Premium and LiteOn recorders as readers. In addition, CDSpeed gives back a total quality score for each disc, calculated by using the average and maximum values of both C1 and C2 errors.

For our tests we used Plextor Premium v1.04 CD-RW as a reader, and the reading speed was set to 8x, in order to have the maximum consistency in the evaluation results.

• Taiyo Yuden 48x @ 40x

• Taiyo Yuden 48x @ 32x

• Taiyo Yuden 48x @ 24x

• Taiyo Yuden 48x @ 16x

• Taiyo Yuden 48x @ 8x

• TDK 48x @ 40x

• Imation 48x @40x

- Summary of C1/C2 measurements

The error rate is low for all the recording speeds. and none of the discs gave back C2 errors. The results confirmed the jitter measurements and higher C1 was reported in the same areas where jitter was increased. Starting from the Taiyo Yuden media, the 24x and 8x recording speeds gave the best quality score, and the less total errors. The 32x speed gave the highest total amount of errors as well as the highest average C1 rate. Last, the 16x and 40x speeds got the lowest quality scores, mostly because of the maximum C1 values and the total amount of errors reported (adequate, however).

The lowest quality score among the all the media we tested was reported with Imation 48x media recorded at the maximum 40x speed.

Note that the CDSpeed will only report uncorrectable C2 errors. CD Speed can also show fatal read errors (sector(s) cannot be read) indicated in red color.