Ricoh MP5240A Vs AOpen DRW4410 - Page 12

Writing Quality Tests

Ricoh MP5240A

We used 80min 48X CD-R media by Taiyo Yuden and burned the same AudioCD project at 8x, 12x and 24x. Below you can see the 3T Pit & Land Jitter graphs.

- 3T Pit results

As you can see from the graph, the pit jitter is increasing in the outer addresses of the disc, as the writing speed goes higher. The problem is mainly located in the 24x speed, where the pit jitter values reached the 41nsec. The lower speeds also gave pit jitter higher than expected, but they probably cannot influence the overall quality.

Considering the high frequencies of the signal we measure, we could say that it is very sensitive to noise factors such as jitter. However, some manufacturers accept these values although they exceed the 35nsec standard (Red Book).

In the following graph you can see the average pit jitter values (nsec) for the supported writing speeds. Note that longer bars indicate higher values.

- 3T Land results

Measuring the 3T land jitter has the same importance as the 3T pit jitter. Below are the measurements for the same discs recorded at 8x, 12x and 24x.

This time the lower recording speeds gave the highest land jitter values. There are some other cases where the 3T Pit jitter is different than the 3T Land jitter values or vice versa, but usually recording speeds such as 8x and 12x give back better results. Contrary to the pit jitter, the land jitter for the 24x disc is low.

The average land jitter values are illustrated below.

- Summary of 3T jitter measurements

Things are kind of complicated here. Despite the selected recording speed, either pit or land jitter measurements were increased. Although we tried to isolate the better recording speed for quality results, both lower and higher speeds gave the same average performance. We proceeded with some C1 / C2 measurements on the same CD-R discs.

- CDSpeed CD Quality Check

CDSpeed v2.02.011 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 v1.02 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 @ 24x

• Taiyo Yuden @ 12x

• Taiyo Yuden @ 8x

The error rate is low for all the recording speeds. The disc recorded at 8x got the highest score, followed by the 12x and the 24x discs. None of the discs gave back C2 errors.

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.