Ripping Speed? Wave Files/Sound Quality

My question is this: if ripping speed doesn't matter and bit-perfect copying is assured so long as you rip with error correction, then why are so many audiophiles intent on using Exact Audio Copy and why does the Nova Physics Memory Player tout its Read Until Right methodology as a key component of its great sound? Something doesn't add up.

Actually, it adds up just fine.

Lots of people like EAC as it puts forth more effort than most ripping programs to assure an accurate read. I've had EAC spend more than 30 minutes, an hour or more trying to rip a single regular length song. Depending on the extent of damage, portions of a CD simply may not be accurately read no matter what the effort.

My music server is based on Linux so most of my ripping is done with the CD Paranoia based system but the goal is the same. Ripping speed is simply a function of how fast the program thinks it gets an accurate read. On a disk in good condition the process is fast so there is no reason to slow it down.

Most CD players read real-time. People want to hear music when they hit the play button so the amount of memory buffering available is nominal. Note that real time playing is inherently a 1X speed. (Not many people want to hear Pavarotti sound like a chipmunk.)

You might also check into the Reed Solomon C1/C2 error correction that audio CDs utilize. There is a difference between error correction that picks up correct data from another interleaved area of the disk and interpolated data if all the areas for a frame are damaged. A good start is Andy McFadden's http://www.cdrfaq.org.

Sorry, I still don't get it. Why put forth all that effort if it doesn't make any
difference? You said, "data programs - which are not allowed ANY errors
during the installation read - have no problem installing at high speed if the
disk isn't damaged. The error correction scheme in audio CDs isn't a robust as
for data, but it is still effective."

I've been trying to figure out to burn CDs with quality equal to the original.
Some people say you need a program like EAC, but I can't believe that is the key
to it.

Let's put this another way. Data programs are not time sensitive when they install. The CD drive can re-read the disk as many times as it wants. If the disk is in good shape, it reads the disk perfectly at 50X (or whatever.) If the disk is in poor shape, it tries until it gets it right. If it never gets it right, you get an error message that the program can't install correctly.

When you rip a CD on a computer, the drive has a similar opportunity for multiple reads within the confines of Reed Solomon. If an audio CD does not need to be re-read, it rips quickly. If the drive is having trouble getting an accurate read in an error correction mode, it reads slowly. Slow ripping does not improve error correction if no errors are popping up.

When a regular audio player plays a disk in real time, it has to read it at 1X and get it the best it can the first try. If it has to re-read a section of the disk it can't deliver the music in real time, so audio players typically don't re-read. They may interpolate to fill in the error with a "guess" about the music that should have been there.

Players like the memory player are more like a computer drive. They stream the data into a memory buffer and the actual 1X output is sent to the DAC from the memory, not the CD itself.

However, with your last sentence you introduced a variable that hadn't been on the table in the earlier discussions. You indicated you want to "burn a copy." An original CD is encoded using pits and lands that are pressed into the CD. A CDR is layered with a special coating that creates the binary code by burning the appropriate areas with a laser, which then become non-reflective.

It can be argued that some stand-alone players read a commercially produced CD differently than a CDR. (Some audiophiles claim that CDRs are generally superior to CDs.) However, anytime you're playing something in real time, jitter becomes an issue. Jitter is a function of timing precision in the decoding from digital to analog. It is not an issue when you're only talking about accurate data transfer during the ripping process.

So two different issues at work. Ripping is a data transfer function. Playback (from whatever source) is a different can of worms.

Thanks, very clear and helpful. And I'm sorry to be so dense about this, but would EAC be meaningfully better at capturing the data of an audio CD than, say, iTunes, which also rips at whatever speed it needs and uses error correction?

All of this argues for the inherent superiority -- theoretically at least -- of a hard drive based music system, doesn't it, since the data will be captured with whatever it takes to read it all, in contrast to the real-time reading of your typical CD transport (the new PS Audio transport will be an exception). Assuming jitter is managed sufficiently well.

I personally don't know how extensive the iTune error correction system is. EAC has an "Accurip" feature that compares your rip against a database and gives you a "confidence" reading for the quality of your rip.

However, over the years I've not had too much problem ripping disks. As noted before, I do most of mine on a Linux system, but I have done ripping on a variety of other systems over the years and never been displeased with results when the CD is in good condition. I use a music server with a Squeezebox and an external Lavry DA10 DAC. It handles my collection in a way that allows me to enjoy the music without constantly obsessing over things.