Has CD Quality Control Slipped?

morris57 asks: "In the past few months, I have had at least 3 brand new compact disks or DVDs not work right out of the box. I don't mean that any sort of copy protection on the disk prevented me from using them; they were simply defective disks. I was able to exchange my DVD of 'The Matrix Reloaded' at Best Buy for a working copy, but some disks I got for Christmas I just recently opened and they are either unplayable or garbled. It is not a hardware issue, either. I've tested the disks in several types of players: new, old, component, computers, etc... It seems to me to make a very good case for downloadable media files, although I know these tracks are not available on iTunes or audible.com. So, I guess I'm wondering if the Slashdot community has noticed a decline in quality control of CDs/DVDs. What can be done (individually or communally) to not get burned by defective disks?" The solution for this particular type of problem boils down to simple consumerism. If you get a defective product, return it! If manufactures notice a high rate of return (and they should), they'll hopefully address the quality of what they ship. Has anyone else noticed an increase of non-working DVDs or CDs?

Comments

Re:Stating the Obvious

[GoRK]

I have never been to a store that would not exchange an opened copy of a CD or DVD for the exact same item if it was defective and included all the original materials.

Cheaper CDs?

[jeffkjo1]

I feel like this has been occuring, but I don't know enough about the technical specs of how cd's are made to prove it.

However, in the past 6 months, I have purchased several CDs, and have had to reburn (checks disc box) 4 of them. I've also reburned several of my recent CD-R mix cd's. I don't know why, but after only a few weeks of use, these CD's have begun to skip. I have many CD's that are pushing 10 years old and are still going strong (which is amazing, considering some of them look like I scraped them across pavement.)

For some reason CD's I've purchased recently aren't holding up as well. If anything, I'm treating my CD's better than I used to, I just don't get it.

Are they making the actual data layers out of thinner/cheaper metals? Whats going on? I can't be the only person that's noticed this.

Re:It may be more than manufacturing flaws

[hankwang]

>This may be my imagination, but CDs that I bought in the early 90s felt a little heavier and appeared a little bit thicker than CDs that I buy now.

That's not imagination. I once attended a talk by someone from Philips Research. Accordig to the CD specs, the plastic layer on the playing side of the disc should be 1.0 mm thick with a tolerance of +/- 0.1 mm (I don't recall the exact numbers). According to him, after a few years, all CDs on the market had 0.905-mm-thick plastic layers because it was possible to manufacture them with much tighter tolerances and this way, the manufacturers save 10% on the raw material.

In the DVD specification, the tolerances are much tighter, which is necessary because the laser needs to be focused onto a much smaller spot than in a CD.