Fate of Io: How to test CDR media quality

How to test CDR media quality

2003/04/05 20:49:31 PST by Aetrus [0/15]

Here's something I read today on a respectable music forum. Thought it might be useful to you guys with burners.

When comparing wave files the standard test is to take a copy of one wave file and invert the phase. Then insert both into an audio editor like Sound Forge and line them up EXACTLY from starting sample to starting sample. If the files are a perfect match you will end up with total silence since both phases will cancel out. IF there are any artefacts then you will hear them. That is also how you test CDRs for quality. Burn a track and then extract it with the best extractor you can find. Invert the phase and compare. The crappier the CDR the more artefacts you will hear. It's important to have a high quality ripper so you won't introduce and artefacts with that program. That would colour the test results to be sure. I use the one inside ACID Pro 4. Hard to beat that one for quality. Its important to have good audio editor as well I use Sound Forge 6.0 Studio which is the demo version of the big pro end editor. (industry standard for window second only to ProTools)

In a few test burns on various speeds. (3 passes each) Maxell CDRs tested A to A+ while TDK tested F. There were quite a few other manufacturers listed, but I don't remember them all!

There you go. A nice way to test your CDRs!

2003/04/06 01:52:11 PST by Temporal [manager]

Hmm... there should *never* be artifacts of any sort on a CDR. A single error in any digital recording would likely cause a very noticeable pop in the middle of the music. That's what is so great about digital: if you aren't getting 100% exact perfect quality, you will know it. So, I wonder how it is possible for any type of media to fail this test.

2003/04/06 11:26:17 PDT by Aetrus [0/15]
Edited at 2003/04/06 11:33:36 PDT

Here are some quotes from the actual thread. Hope this clears it all up! :)

Quote:

The discs made by Taiyo Yuden (which include Maxell and Fuji, at the moment) test out as A or A+. The Mitsui discs (apogee and TDK) currently are testing as an F. These discs were tested by Sienna Digital in San Mateo, California.
Hope this is helpful info.

Quote:

quote:
What did they find negative about the Mitsui's? I've always used Tiayo Yudens, but a friend that was quite the audiophile loves the Mitsui's....

There were apparently serious block error rates. These were bad enough that Discmakers was unable to use the disc to create a glass master because the machine couldn't even read it (they stuck it into a drive that could read it and made a copy to burn the glass masters from, but that's another story). I haven't seen the test that Sierra did, but I know the president and I know how he works (he's German, very thorough). The older Mitsuis were good, but thay seemed to have changed formulations. I heard about a program that will read the formulation track on the disc, which will tell who made the disc and what formulation was used. I will try to find out if there is a URL and post it here.

Quote:

Do your own tests with your own burner. One test I have done is to burn a track to CD, extract the track, invert the phase of the extracted track, and mix it with the original track, all in software (I use Sound Forge). You may have to align the starts properly. Any bad reads or writes will have results in the mixed file.

Here's the URL they mentioned:

Sienna Digital

And here is some more generic info on CDRs and manufacturing:
CDR Info

And here is a link to the actual thread if you'd like to read it yourself.

CDR Thread

That site is a major distributor of high end music equipment from flutes to complete Digidesign ProTools systems. Their online glossary of terms is close to comprehensive. If you ever wanted to know what a Voltage Controlled Oscillator, or Voltage Controlled Amplifier does and it's relation to analogue synthesis that would be a good place to start. Not to mention it being a damn good place to buy music related products! They actually have EXCELLENT customer service! (a rarity indeed)