In the Nero DiscSpeed – Advanced DAE Quality Test window, you can run the advanced DAE quality test, and the result is also shown there.
The results are displayed in the Test results and On-the-fly copying areas, as well as in detail in the display area. A progress bar at the bottom of the window indicates the status of the test while it is running.
In the On-the-fly copying area, the test determines whether an audio CD can be copied without causing errors at various speeds between 1x and 16x, i.e. indicates if the optical drive is suitable for use on-the-fly in combination with a recorder for backing up audio discs.
The results of two tests are displayed in the Test results area: the Sequential read test and the Random read test. The sequential read test simulates the digital extraction of audio files (DAE) under ideal conditions and then runs a harmonic read test. This test helps you to identify errors on the disc. There are two different types of error.
A search for data errors returns audio samples that were not read correctly, based on a comparison of the read bytes with the known data from the test disc. Minor data errors can be corrected using the drive’s error correction feature. The most common cause of data errors is poor-quality discs. Avoid data errors by using high-quality discs and/or reducing the drive speed.
Synchronization errors occur when, instead of reading the required audio sectors, an optical drive reads the adjacent sectors. Nero DiscSpeed uses special data on the test disc to check if the correct sectors are being read. Synchronization errors can result in samples being lost or repeated. These errors can be audible.
You can define preferences for the optical drive test in the Advanced features area. Optical drives start from different positions when reading audio sectors. There is also no standardized start position for the write process of recorders – there is usually a gap of a few hundred samples. The following check boxes are available:
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Read Leadin
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If this check box is enabled, the capability of the optical drive of reading the leadin is tested. To create perfect copies, an optical drive should begin reading data before the actual start position.
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Read Leadout
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If this check box is enabled, the capability of the optical drive of reading the leadout is tested. To create perfect copies, an optical drive should read data from the leadout.
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Read CD Text
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If this check box is enabled, the capability of the drive of reproducing CD Text is tested.
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Read Subchannel Data
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If this check box is enabled, the subchannel data is read during the test.
Subchannel data contains information such as index markers. An optical drive must be able to reproduce this data if it is to create perfect audio copies.
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The following information is available in the Test results area:
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Average Speed
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Calculates and shows the average speed of the completed test.
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Data Errors
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Lists the data errors found.
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Sync Errors
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Shows the number of synchronization errors found.
Synchronization errors occur when data is correct but has been moved by one or more sectors.
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Quality score
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A percentage is calculated based on the results of the test. A quality index of 100% is perfect, i.e. there were no errors.
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| On-the-fly |
The name on-the-fly describes a burn process for discs. In this process, data is written to the disc directly from an image.
| Lead-in |
The leadin is the starting area (innermost area) of user data on a data carrier. This is where the table of contents and additional information concerning the disc is stored.
| Lead-out |
The leadout is the ending area of user data on a data carrier that is used to close a session. If the disc has not been completed yet, the reference for the next session is stored here.
| CD Text |
CD Text consists of additional information on a CD that can store e.g. music track titles and artists. CD Text is stored in the so-called lead-in area of the CD before the audio data starts. The display on the CD player shows the additional data. You must have a CD burner which supports CD Text to enable the CD Text to be written to a CD. In particular, CD Text can only be written in disc-at-once mode.
| DAE quality |
DAE (Digital Audio Extraction) refers to the process of reading audio files with a drive. DAE quality indicates how well a drive reads data on a CD.
| Subchannel data |
Subchannel data on a disc contains additional information, such as CD Text or information on positions.