Optical drive

[mansr]

It is also my understanding that there can only be two types of rips: one that match the binary data on the CD (correct ones) and ones that don't (incorrect ones).

 

Alex has observed rips that seem to fall between the two. They are correct and identical to each other at the binary level but the quality varies according to the power supplied to the drive during the ripping process.

 

I don't believe that such rips can exist. What do you think?

 

If that were possible, computers as we know them could not exist. In fact, the universe as we know it couldn't exist under such circumstances.

[mansr]

For me it is also not understandable at all, why bit-identical rips do sound differently. And hell yes they do, as I personally found out in my system.

 

How did you find out? Did you take any measurements?

[mansr]

mansr

As you are a new member here, you may not be aware that respected E.E. and Technical Journalist Martin Colloms from HiFi Critic Magazine ,has previously performed a series of 6 positive separate Blind A/B/A 3 minute tests with comparison .wav files that I supplied to him. If you are genuinely interested , you will find further information at the attached links, as well as learning something from Alfe who is well qualified in the design of BluRay writers and other related areas. If you have come here to tell us all how stupid we all are, I would suggest that you leave this thread to those who are interested and don't try to disrupt it.

 

Let's say there is indeed an audible difference between different rips despite the files being bit for bit identical. This means there must be some other difference, beyond the data content, influencing playback. Computers and operating systems being what they are, this is a possibility I'm willing to entertain. It could be related to fragmentation on disk or some other intricacy of the management structures in the OS or hardware. Where things get mysterious is how these differences are able to propagate together with the file data when they are copied to another storage medium or even sent across the internet. A file transfer program (be it browser, email, FTP, or something else) would not, and should not, attempt to discern and convey such hidden properties of the files. It seems, to me, mighty strange that these differences, whatever their nature, are able to undetected pass themselves along through a variety of channels not designed to accommodate them. Nevertheless, people report hearing differences. As an engineer, it goes against my nature to simply leave it at that without any explanation. The first step in obtaining an explanation is to determine precisely what we are trying to explain. That means measuring the signal somewhere along the playback chain and identifying something that correlates with the perceived sonic differences. In all of the discussions about this phenomenon I've read, nobody has yet presented anything along those lines. There is even outright hostility towards the notion of applying a little science to find out what's going on. Until that changes, I'm going to continue believing that it's all in peoples' imagination. Even the best and the brightest are susceptible to tricks of the mind, which is why we must at least try to measure things using objective methods.

[mansr]

mansr

It may surprise you to hear that when these comparison .wav files with identical check sums are burned to a quality CD-R , that audible differences still remain when played through a good CD/DVD/BR player , yet when ripped back to a HDD, the checksums are still identical.

 

Alex

 

Enterprise storage systems commonly employ deduplication, a space-saving technique whereby blocks of identical content are stored only once. I wonder how these files would behave after a trip through such a system.

[mansr]

After error correction as in unrecoverable errors?

 

Still 10 a second, although obviously undesirable, could still be acceptable for audio.

 

No, 1e-12 is roughly one error every 8 days.

 

I assume this doesnt go for data storage? Data is stored differently then audio?

 

Edit: ofcourse it is but data can be recovered 100% right? Just audio cant?

 

Data tracks have an additional level of error correction that reduces the error rate further. It is impossible to get an error rate of zero with any medium. Hard drives typically have an error rate around 1e-15.