Sound Check CD

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Hi,

Here are the three CD that I use mostly;

Track 71. This track tests the radiated distortion characteristics of your system. A sine wave from an Audio Precision System One was processed through a special devise that enables us to regulate the amount of distortion desired. The initial signal started with about .0004% distortion. It was processed and recorded on track 71 as a reference for the following tracks. On this track the tone has about .03% distortion. In each track following, the distortion is raised by a factor of about 10 dB. If you have a distortion analyzer, you can check its calibration as the distortion on the following tracks is very precise. Of course if you have a noisy CD player, or a poor D-to-A converter the THD+N may affect the lowest reading of this series of tests. If you don't have a distortion analyzer, you can use these tracks as a masking test. The concept of masking test is simple. By starting out at low levels and increasing the distortion until it is just audible, you have an indication of the distortion threshold of your system or your ability to perceive it. Start with track 71. If you are unsure of what distortion sounds like, skip to track 76 because track 76 has exactly 10% distortion and should be clearly audible to anyone on even a terrible system. Distortion is the slight buzz mixed in with the pure tone. If you can't tell the difference between any of the tracks, the distortion of your system is very high (over 10%) or your hearing is very bad (you've been in car audio for too long). Most people can easily hear 1% distortion on a good system with sine waves.

Track 72. Same as track 71, except with .1% distortion
Track 73. Same as track 71, except with .3% distortion
Track 74. Same as track 71, except with 1% distortion
Track 75. Same as track 71, except with 3% distortion
Track 76. Same as track 71, except with 10% distortion


From "My Disc"
The Sheffield / A2TB Test Disc

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Track 37: Silent Track (digital zero)

From Denon Hi-Fi Check CD CO-75046
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Track 7 : Nightingales "Dawn on ST John's Day"
Real live digital recording of nightingales at dawn in summer.

Pierre Verany Records PV.784031 Made in France 1984 compact test demonstrations disc

Good Luck
Chris
 
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