CD roms and audio CDs use different error correction, so I think it's not true to infer that audio CDs have a zero errors just because you can retrieve files without error from a CD-ROM.
I personally don't believe that a copy can sound better. I have yet to hear a convincing explanation of how they possibly could. |
The hard yards to overcome in CD playback and recording are timing errors, not bits. You may trap all the bits but if the timing is not perfect (and it never is) you'll get jitter which, if gone untreated, turns some people into LP junkies. |
I agree with Rockvirgo that the errors are not in the bits. But when we are talking about going from digital to digital, we are not talking about jitter either. Jitter is the distortion introduced due to timing errors during the analog to digital or the digital to analog conversion. CD to CDR involves no analog phase.
It is my belief that CDR's should sound identical to CD's and I have never been able to hear a difference. As I understand it, the only way a CDR could introduce jitter is if the physical layout of the bits on the CDR are not fixed, meaning that the burnt in physical orientation could vary from the intended original orientation which could then introduce a timing problem on playback. But to my understanding (and I do not know for sure), the physical orientation of the blank is in fact fixed, ie, we could point to a specific spot on the blank disk and say "the first bit will go there, the second there, and so on." Am I wrong about this? |
I agree with the above posts. I am the owner of a media duplication company; and we duplicate CDs, CD-ROMs, and DVDs. Based upon my 13+ years in the commercial audio and video business I think I can say with some certainty that if you want to duplicate a CD and get decent results it has to be done at 1X or 2X speeds.
Not only do higher duplication speeds create jitter and timing errors; but resulting discs usually sounds flat and lacking in dynamics. I recently duplicated over 200 CD-Rs that each had a different radio commercial on them. They were entries in a festival for Radio & TV Commercial producers. At least 10% of the entries were unplayable. In doing some follow-up, I called the producers and almost every single CD-R that would not play in the five CD players in our studios was "burned" on a computer at high speed.
So take a word of advice - and stick to 1X or 2X CD duplication if you want to get some decent results. Happy listening. |
If done correctly digital copies can sound better than the original. If done incorrectly digiatl copies can sound worse than the original. |
Gboren, jitter most definitely occurs in the digital domain. Do a Yahoo search for "jitter definition" to see some examples. It should be easy to imagine that the "pits" on a CD won't be perfectly timed, and that the quality of the media as well as the burn rate can affect this. I also want to reiterate that music (Redbook) CDs do not have the same error correction method as data CDs! |
I burned my cd by using computer cd re-writer @ 3x. The copy sounded about 85-90% of the original. I play them on the Sony XA7ES for comparation (with the high end system ,i.e cables,amp ,preamp and speakers). I think we have to use very good equipments to hear a difference. |
"If done correctly digital copies can sound better than the original. If done incorrectly digiatl copies can sound worse than the original."
Could someone elaborate this statement? Frankly I still don't understand how one can get a copied CD that sounds better than the original.
Ake |
Great discussion! Please can someone respond to my original question though, which is if I have some copies I made at high speed (for which I no longer have the original), will I get better sound if I copy these 8x copies again to a 1x copy? |
No you will not get better sound than what is already on the cdrs you have. |
Matt8268, if you get a low jitter bitstream identical to the original CD, in theory you could achieve a better sound quality by re-recording at X1 speed for the reasons mentioned above. Do you have a way to do a bit-compare on audio CDs? Just try it and let us know. Be advised that small differences in jitter may only be audible on higher-fidelity systems. |
Matt...try it and then go have a liten with volume levels as closely matched as possible....then tell us what you think? |
Ake, I was surprised by this as well. I have a CD copy done by a Thomas W. Shea, E-mail; http://www.sunset.net/musicman that is absolute proof that a copy can be better than the original. I'm not sure if it's due to sucessive upsampling,oversampling and/or error correction but there is no doubt that it's better than the original. This copy was done before my eyes at a Sterophile show in NY many years ago in conjunction with the folks from Audio Alchemy. I also have copies of CD's given to me by friends done on their PC's and they are not as good as the over the counter examples. Whether it's due to added jitter or to some kind of electronic distortions added by the inner working of the computer I don't know, but I do know that it's audible. |
"If done correctly digital copies can sound better than the original. If done incorrectly digiatl copies can sound worse than the original."
They can sound better if you get all the members of the band together and have them re-record the music. when you are coppying it can only get worse or stay the same. |
lchapper, I beg to differ. |
The original copy is digital, the second copy will be analog, not digital due to copy protection. Unless you get a "pro" version which ignores SCMS copyright protection. |
my own experience on this is very simple, i tried it
and i was shock on the result,i dont know if you are
familiar with mapleshade recording co. the guy who
own founded the co. is a genius,all i did , itreated
the copy with this mickro-smooth maple shade product
it gave it a full sound and eliminate the edginess
and brightness gone.According to him, he uses this
on one of his recording but as far as i know the
cd he mention is on HP list if iam not mistaken
it is the Kendra Shank,try it,upsamling will improve it
of course.to clarify treat the copy before burning in. |
Cdc, not all CD's are encoded as such. Many CD's can be copied in the digital domain. |
