Theoretically, CD players should be able to perfectly correct errors
up to 2.47 mm across. In practice we found some players capable of
correcting 2.0 mm errors. CD-CHECK simulates realistic errors of
0.375, 0.750, 1.125 and 1.500 mm. In order to cope with manufacturing
errors and dust, scratches and fingerprints CD or DVD player should
be able to pass at least Check Level-2 with 0.375 mm errors. Our
recommendation will be to get a player which will pass at least 0.750
mm or 1.125 mm errors. You will find that there are many players which
are only capable to play Check Level-1 or Check Level-2 on the CD-CHECK disc.
And that is when they are new. With time their performance will dip
below the acceptable level.
to evaluate existing CD, DVD and CD-ROM players for data loss
CD players detorierate over time. Protect your audio investment by
detecting pickup defects early. Use it to determine when pickup
are needed. Use it to check the adjustment effectiveness. Test your player
especially prior to warranty expiration. If you are a service shop technician
use CD-CHECK to help you with the rapair process.
to determine if the laser lens needs cleaning
Dirt accumulates on laser lanses of CD, DVD and CD-ROM players and
recorders. There are CD-based products that will clean dirty lenses. (Only
high-quality products should be used since low quality products can damage the
lens after repeated use.) Some cleaner manufacturers recommend cleaning the lens after
every 8 hours of playback, which we consider unnecessary. CD-CHECK will
determine whether the lens truly needs to be cleaned, saving it from
potential abrasions caused by unnecessary - and repeated - cleaning. CD-CHECK
can be also used after the cleaning process to check its effectiveness.
to evaluate the safety and effectiveness of sound-enhancing technologies
Many gadgets and gizmos that enhance the sound of CDs/DVDs are very difficult to test objectively.
Therefore, many evaluators rely on subjective audition tests, which can be very unreliable. Many of these
sound enhancing technologies claim that they improve signals. Since they mostly affect only the digital
signal, CD-CHECK can be used to evaluate them objectively and simply. If any of these technologies
improve the playback of CD-CHECK's test signals, this clearly indicates that they reduce the number of
errors generated, which in turn can lead to better sound quality. But, if no change is observed, it means
that a given technology does not work in this particular instance.
Sometimes these sound-enhancing technologies actually cause the sound to deteriorate. They can even
harm a player's mechanical systems, which could lead to premature mechanical failure. Some reviewers
will probably hear the difference, and might even prefer distorted and interpolated sound over the real
thing. Internal tests at Digital Recordings and by our associates indicate that this may be the case with
some technologies. But we prefer undistorted and faithful sound reproduction -- and we're sure that you
do, too. With CD-CHECK, you can be sure that's what you're getting.
Empower yourself with CD-CHECK !
Do not expect manufacturers, sales people and audio magazines to represent
YOUR interests !
Digital Recordings supplied the CD-CHECK disc, free
to most of the audio magazines. Some are using the disc in their equipment
reviews, others decided to ignore it and continue supplying you with false
data regarding the CD and DVD players performance.
So, if you are looking for a player that offers 100% of music and not just an
approximation you need CD-CHECK to test the player yourself.
Furthermore, you should remember that CD players vary in quality from sample
to sample and from manufacturer to manufacturer. There are vast differences
between players often not related to the price of the player. Crucial to this
performance diffrence are the CD transport mechanisms. They vary in price
from $15 to
$250. Some manufacturers are trying to save money and some have inadequate
test procedures and quality control. (Recently we heard of a $10,000 CD player
from a reputable
manufacturer poorly performing on the CD-CHECK disc.)
Make sure you are buying a player capable of reproducing 100% of music. Use
List of audio magazines which have CD-CHECK disc(s):
- "Absolute Sound"
- "Audio Amateur"
- "Audio Critic"
- "Audio Electronics"
- "Audio Ideas"
- "Inner Ear"
- "$ensable Sound"
- "Stereo Review"
- "Ultimate Audio"
- "What HI*FI ?"
List of some audio manufacturers who have CD-CHECK disc(s):
- Clover Systems
- Mark Levinson
- Madrigal Labs
- Harman International
- Polyfusion Audio
- Balanced Audio Technology