Testing Drive Quality

[EliC]

Re: Testing Drive Quality

Oops, works much better when I post the link:

http://www.mscience.com/test.html*blooper*DRV

[bhoar]

Re: Testing Drive Quality

I would REALLY like to get my hands on this, but at ~$5k, I don't think so...

What is it that costs $5K?

-brendan

[EliC]

Re: Testing Drive Quality

I would REALLY like to get my hands on this, but at ~$5k, I don't think so...

[bhoar]

Re: Testing Drive Quality

Hmm, not many details. I don't think we have discussed them before. I guess the user has to listen to the tone.

It *may* be the case that the audio data is identical for each track, excepting the damaged areas - which might be potentially useful. We'd have to check.

Also, I don't remember if the pressed disc is damaged by printing marks on the read side (a la the previously discussed methods) or by pressing it with a damaged (or otherwise altered) glass master. I'd have to check and I'm not near it at the moment. It is a pressed CD, though, not a CD-R.

BTW, Brendan, I sent you an email and PM, if you have time to reply.

Yup, I'll try. It's been too crazy for robot stuff lately, hopefully things will settle down this fall.

-brendan

[EliC]

Re: Testing Drive Quality

Hmm, not many details. I don't think we have discussed them before. I guess the user has to listen to the tone.

I really want to test the reliability of C2 errors of different drives, as well as drives ability to reads discs with damage.

I think this could be done by taking a good quality disc, ripping it, confirming the rip is accurate and saving the disc image as a wav.

Then damage the disc. Re-rip in multiple drives. Look at frames where C2 errors are recorded and bit compare results with the accurately ripped wav.

Ideally one would have multiple copies as the ideal damage would be a number of tracks with various amounts of damage, some easy to recover, some nearly impossible to recover.

dBpoweramp already has everything that would be needed. It just needs a mode to do this and a nice output graph.


BTW, Brendan, I sent you an email and PM, if you have time to reply.

[bhoar]

Re: Testing Drive Quality

Eli -

Have we discussed using one of these before? Would it even apply to what you're trying to do?

http://www.digital-recordings.com/cdcheck/cdcheck.html

-brendan

[EliC]

Re: Testing Drive Quality

I am also trying to use Andre's app, if anyone has any advice please comment:

http://www.hydrogenaudio.org/forums/index.php?showtopic=74489

Still hoping for something I can use with pressed discs

[EliC]

Re: Testing Drive Quality

Thought about this some more. Clearly the problem is that you need to know what the exact data is on the disc. So you would have to take a good disc(s) and intentionally damage them. Of course easily done. But would still require a mode in the ripper for this. Discs would need to be ripped, wavs saved, then damaged, and re-ripped.

[EliC]

Re: Testing Drive Quality

Exactly why I am saying that dBpoweramp's CD ripper could be used to aggregate this information if users ripped the SAME disc with errors in multiple drives as long as that disc is also in accuraterip.

[Spoon-]

Re: Testing Drive Quality

Most tests use CD-Rs, I am a believer that such tests are invalid as CD-R are not the same as pressed CDs.

[EliC]

Spoon,
One very common question here and at HydrogenAudio is what is a good DAE drive. In addition, no tools are currently in use by review sites that really put drives to the test. Could the CD Ripper be used in a DAE Quality Mode? This may give the audio community a badly needed tool, and become a new standard for hardware review sites.

By using the same disc(s), ideally one with some recoverable and some unrecoverable errors, in multiple drives the community could begin to test different drives on the market.

If the disc(s) used by a user is in accuraterip and the user has multiple drives you could test:

- Are all C2 errors reported? If different drives report C2 errors that 1 drive didn't report, then its missing C2 errors, or if no C2 errors are reported and the track is innaccurate, then C2 errors are missed, correct?
- Are all C2 errors real? If C2 errors are reported but the track is accurate, then the C2 errors aren't real (false errors) correct?

In addition, it would test the drives ability to recover from errors.

A full test suite could also create a disc with a hidden track one audio, and audio in the lead in and out, and test the drives ability to read these.