The Advanced DAE Test will reveal all DAE problems a drive may have.
By using a special test disc, which must be created with Nero CD Speed, even the smallest error will be detected.
There are two kinds of errors which can occur:
Data Errors
These are just audio samples which are read incorrectly.
The cause of these errors is usually bad media. A solution is to use different media or decrease the drive's speed.
If the number of data errors is not too high you probably won't hear them because the internal error correction routines of the drive should be able to fix them.
Nero CD Speed detects them by comparing the read bytes with the known data from the test disc.
Sync Errors
A sync error occurs when the drive does not read the audio sector requested by the application but a sector near it.
For example when the application requests sector 1000 the drive may return the data from sector 999.
When this happens either some samples are missing or samples are repeated. This error is probably audible.
The test disc contains data which allows Nero CD Speed to determine whether the correct sector is read.
The sequential read test simulates DAE under perfect conditions. Most drives will pass this test without errors.
The harmonica read test is very though for the drive. Many drives will not pass this test without errors.
Based on the number of errors a score is given. A score of 100.0 is a perfect score.
After checking the DAE quality, the test will determine whether the drive can be used in combination with a recorder to make backups of audio discs on the fly.
The test will check if an audio disc can be copied without any errors at different speeds ranging from 1-16X.
Finally some advanced features of the drives are tested:
Offset
All drives start reading audio sectors at a different position from the actual start position.
This offset is usually a few 100 samples. Also recorders don't start writing at the start position.
Nero CD Speed reports the total of the read offset of the tested drive and the write offset of the recorder which was used to create the test disc.
Read Leadin
To make perfect copies a drive should be able to read data before the start position (see offset explanation).
Read Leadout
To make perfect copies a drive should be able to read data from the leadout (see offset explanation).
CD Text
Checks the drive's ability to return CD Text information.
Read Subchannel Data
Subchannel data contains information such as index markers, track number, etc..
A drive must be capable of returning this information to make perfect audio copies.
