Backup ANY Movie DVD - Fully playable in ANY DVD Player!!!

Home


CD/DVD MEDIA LISTS
CD-R
CD-RW
DVD-R / RAM
SEARCH SITE
CD/DVD SOFTWARE
CD-Writer Software
CD-Writer Tools
CD/DVD Utilities
DVD-Writer Software
MP3/AUDIO SW/HW
Audio/MP3 Software
MP3 Hardware Players
Related MP3 Links
CD MEDIA
80 Minutes CD-R's
99 Minutes CD-R's
CD Factories
CD Recordable History
CD-R Dye Info
CD-R Quality
GD-ROM Information
OverSize/OverBurn CD-R's
Philips Inferior Quality CD's
TDK Inferior Quality CD's
CD WRITERS
CD-Writer Modifications
CD-Writer Technology
Repairing a CD-Writer
Standalone CD-Copiers
CD ARTICLES
CD/DVD Protections
CD-R Glossary
CD-Writer Burn Tips
Create a Copy Protected CD
Magazines/Press
Technical Information
Related CD Links

Buying a CD-Writer
CD Reviews
CD-Writer Firmwares
Class Action Philips & HP
File Sharing Software
DVD ARTICLES
DVD-Writer Technology
DVD Reviews
Related DVD Links
HARDWARE
Mainboard & CPU Tools
FEEDBACK
Message Forums
Advertising & Support
Submitting CD Info
NETWORK
LinkWorld
GameTarget
CoverTarget
MusicTarget
CD Links / DVD Links
Files
The Vancouver Sun

Recording with CDs is a bit of black art

The quality is improving for CD-Rs, but there is still a very long way to go.
John Dvorak Vancouver Sun

The continuing discussion on the quality of recordable CDs has generated a huge volume of mail. The following points from H. Nakajima of West Vancouver are a valuable contribution:

"Once a CD-R [Orange Book] is burned with audio data, the disc turns into a Red Book [CD-DA] disc, which is supposed to be readable by all the audio CD players.

"Red Book specifies [among other things] the amount of laser light reflecting back from the disc surface [pitch and land] when exposed to reading laser beam spot. This is to ensure [with the given capability of photo sensor] the necessary data retrieval for servo and audio extraction.

"When CD-R was introduced some 10 years ago, it barely met the reflectivity requirement even with the use of 24-karat gold as reflector layer.

"Since then there have been improvements made in this area, but still CD-R is more "difficult" to read than regular CDs.

"There were [and still are] CD players whose reading capability was marginal. I remember when I first made in-flight audio entertainment CDs for airline companies 10 years ago, some of them did not play. It turned out that the drive in the airborne CD player was Sony's very first "cheap" Discman.

"Since the gold/green CD-R, several other types of CD-Rs have become available. All are supposed to be made under Orange Book specifications. However, there are CD-R writers [burners] which were designed before the newer discs [such as silver or blue] became available. They might not be able to burn the newer variety of discs properly.

"Today, there are many CD-R manufacturers with varying levels of experience and production capability. Product variety is so huge that quality uniformity is out of the control of Sony/Philips, the licensor.

"There still is a black-magic portion in CD-R production. If you ask CD-R drive manufacturers which disc to use for the best result, they usually give you brand names or product names they want you to use.

"One of your readers asked about his CD player's difficulty in reading inner tracks. This may well be due to the capability [optics or otherwise] of the player. But it is also possible that the disc is at fault.

"One difference between CD-R and regular CD is that CD-R has a layer of heat-absorbing dye which is applied on the surface by the spin-coating method. Although this centrifugal method is the best available to ensure a uniform layer, there is the possibility of leaving different thicknesses or other properties in different areas of the disc.

Usually, the innermost area and outermost area are more prone to quality problems, including warping. Eccentricity of the centre hole may also be a factor.

"Re: data density on tracks. This is the same anywhere on the disc. Data are laid out on the track in CLV [constant linear velocity] fashion.

"In the case with CD-R74 [650MB], the linear speed is 1.2 metres per second at 1X [audio] speed. Actual rotational speed can be as low as 200 rpm and as high as 500 rpm. [If the CD or CD-ROM is running at CAV, constant angular velocity, accessing a particular point on the surface would be much faster, since sectorizing the data area by angle is possible. But this will reduce the maximum recordable data amount]. The above is just for your information."

-

And reader D. Cheung also comments on the CD-R questions and comments raised in the Aug. 12 Net Works:

"Each of the people who had problems regarding the CD-Rs usually was able to fix his or her problems after switching to a 'better quality' of disc. This compelled me to search for some sort of list that would evaluate the quality of CD-Rs.

"I scoured the Net and found this: www.cdmediaworld.com/cd.htm.

This site had great reviews and also great research on the individual quality of almost every brand in the market. It's a little messy, but I think it's a great resource.

Dvorak: I agree. This is the best resource for such information I have seen.

To send John Dvorak a comment or to ask him a question, write to him at [email protected]

The Vancouver Sun
Thursday 19 August 1999




1998-2017  CD Media World - All Rights Reserved
The contents of this page may not be reproduced/published anywhere else without the written permission of CD Media World
Privacy Statement  -  Terms of Service  -  Contact Us  -  Advertise Here!