Test Media - Page 5

CD-Check

- Purpose

Digital Recordings CD-CHECK is a compact disc which allows evaluation of the CD player's "error correction headroom" (i.e. player's ability to correct data errors) and "tracking" (i.e. player's ability to stay on track despite of disc surface or other errors). CD-CHECK uses special digital signals in combination with disc error patterns arranged over five tracks. The five tracks contain a sequence of progressively difficult tests referred to as Check Level-1 to Check Level-5. The higher the Check Level passed the more reliable the sound reproduction of the CD player. A smooth, continuous tone of 20-seconds indicates the player passes that Check Level. Any clicks, interruptions, skipping or looping indicates failure of a Check Level.

We test each the drive with the following procedure: We used WinXP Windows Media Player to playback the disc, and using headphones we listened all tracks. A continuous tone of 20 seconds plays in each track. If the drive playbacks without an audible pop or click occurring during playback of the tone it passes the check level. The tests are repeated five times. A result of 5/5 indicates that no pops or clicks were heard in 5 out of 5 playbacks of a particular track. A result of 0/5 means pops or clicks occurred during all 5 playbacks of a particular track. Digital Recordings provides the following interpretation of results:

· Level-1 Pass: Player meets minimum requirements
· Level-2 Pass: Average error correction
· Level-3 Pass: Good error correction
· Level-4 Pass: Very good error correction
· Level-5 Pass: Excellent error correction