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General discussion

Fidelity of CD audio copies...?

Apr 25, 2005 4:35AM PDT

I have an on-going debate with a co-worker. He states that whenever you make a copy of an audio CD, the fidelity or sound quality when playing back the copied CD is never as good as the sound quality of the original. I contend that digital audio is just binary code-- ones and zeros, and that there should be no difference between the original and the copied audio CD. Although I have to admit, that I have "ripped" CDA files to MP3, then burned them back to disk as CDA, and there was a very noticible difference in fidelity. But what about just copying the disk, CDA audio, as it is? Does anyone have any information relating to this issue?

Thanks for any and all advice!

Discussion is locked

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Bob K is right
May 5, 2005 10:52PM PDT

Bob K has answered the original question correctly. Error correction covers up a multitude of flaws in CD copying. Yes, some copies are better than others. No, you are not guaranteed an exact copy with normal copying.

For the record, by the way, a .cda file is essentially nothing more than a .wav (44.1KHz 16bit) with additional track data.

.wav is still the "native format" and for a music CD to carry the compact disc logo, it must comply with the "Red Book" specification, part of which is that the audio files meet the spec shown.

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Exact Audio Copy
Aug 15, 2005 5:29AM PDT

Read the explanation at EAC website. Actually ripping a CD into Wave files is not an exact process but EAC gets it pretty close by comparing the samples multiple times to make sure it got the proper rip. That's the ONLY difference in terms of bit-to-bit copying of a CD all the other hogwash aside. I doubt in blind studies of such if anyone could tell the difference between a properly ripped and burned copy and the original disk PLAYED ON THE SAME EQUIPMENT.

Scott

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Verify your disks
May 6, 2005 4:45AM PDT

Computer CDR drives and blanks must handle data storage and one wrong bit can prevent a program from functioning, so both read and write accuracy has to be perfect. It follows that copying an audio disk to CDR or CDRW should be perfect. Just to make sure, I always select the verify option when I burn a disk, which will show that there are no unrecoverable errors on the copy. I have used Roxio and Nero software and both support the verify option. Ripping an audio disk to your hard drive and burning from there adds possible errors from the ripper software, but the original question was CD to CDR copies. There will be no significant difference. Playback, on audio-only players may cause differences. This would be particularly true for portable or mobile players that have to deal with a lot of vibration and are apt to have a lot of mistracking. Different brand blanks are apt to behave differently and CDRWs will simply not play in most older players. A newer player of good quality should have no problems with disk compatability.

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Data and audio are not the same
May 6, 2005 9:24AM PDT

CD-R and audio CDs use a different standard. A data CD that copies correctly will be identical. A music CD will merely meet the "red book" standards.

One wrong bit can prevent a program from functioning. But a little error correction because of a scratch or a read problem will not make music unlistenable.

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Same thing, but different
May 6, 2005 11:40AM PDT

The only major difference between audio and data CD-R's is that there's a certain licensing fee or something like that. It makes the copies legit if you download your songs from napster and then burn them to CD.

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Fidelity
May 6, 2005 7:52AM PDT

a copy is just that, it can be as good as the original or it might not. Never say Never, never is a long time. At any time with the same equipment it always has a chance to be an "exact copy" or not. The bottom line is if it sounds exact to you, it is. If it doesn't, then do it again. You are the judge. Is all relative.

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Pattern recognition
May 8, 2005 3:37PM PDT

Yep on the fidelity. On the other hand due to our good buddy "pattern recognition" a missing bit of the program or sound may not be noticed. Or certainly not as much as something added. I've read without this cover bands would get little work. Probably the orginal bands as well. The mind is a ticky thing and often hears what it expects to. Pretty cool eh? On the other hand "bass is a terrable thing to waste"

later....

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Your co-worker is correct
May 6, 2005 9:20AM PDT

With audio CDs, copying is governed by the "red book" standard. Reading a CD amounts to getting the data off the disk, and using the error correction standards. If the process gets something "good enough" in the sense that it meets the standard, it might not be the same as what was on the original disk. But the idea was to get something that was playable and compensate for errors when playing music, not get something that is byte-for-byte identical, or else give up with an error.

The CD standard was designed to be forgiving of errors and some scratches, and it's possible for copies to get worse and worse in subsequent generations.

It's pretty easy to copy a CD, have the software tell you that the copy worked, and hear noticeable clicks or pops. But even small errors can be there, and whether you hear them or not, it's not a straight binary copy.

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Accuracy of CD copies
May 6, 2005 1:33PM PDT

I'm pretty sure your friend is blowing smoke...
In order to create the orignal digital masters, an analog signal is sampled at some set rate and encoded at some digital value, this sampling will have the largest effect on the fidelity of the resultant discs. The analog to digital conversion is where the loss of higher order harmonics takes place. Once encoded it is a simple matter to just rewrite the same number (digital representation of a sound at an instant in time) over and over to multiple discs. CDA is a standard that incorporates the range discernible to most humans. Unless your friend is howling at fire trucks I doubt they are hearing much outside the norm. If you want to get closer to true audio use WAVE format. It creates a bigger file, because it has a higher sampling rate which allows more definition of the audio envelope. Sound is a composite of many base signals and harmonics, if you are sampling at 44khz and the base is a 15khz tone, you'll increasingly miss the harmonics at say 60khz,75khz,90khz,etc.

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CD Quality, is CD Quality - 1's & 0's are the same BUT....
May 7, 2005 12:34AM PDT

If you make a copy of a CD, with less than an exact copy is is not the same. One person can tell the difference, another may not be able to do so...

You can make an MP3 at highest quality, 360 and those listening may or may not be able to tell the difference. As most listen to MP3's on a computer, the speakers they use are not good enough to tell the difference between an MP3 Recorded at 360 or 192, and the file sizes are quite different. Some can't tell the difference in one recorded at 128, and that saves a LOT of space on your drive.

But, with Harman/kardon speakers on my computer, even though they are not as good as my Stereo System speakers, I can tell the difference... Most of my music I'll copy at 192, to save space on the drive. Then, I use a program called Moodlogic, to play it back. You can choose any artist, genre, or just a mood, and tempo depending on what you want to listen too, and it picks out hours of music for you. As you are doing something besides listening to music, or working on the computer, and most of the time not listening criticaly, 192 is sufficient for real listening pleasure.

However, when I am focusing on music only, and want to be totally immersed in it, then it is on my Stereo, with the best quality earphones I can find. Listening with my eyes closed, kicked back in a recliner with earphones which cancel all outside noises, is an experience which is indescribable... it must be experienced. Very relaxing, and it creates a mental atmosphere or feelings of well being which can last for hours afterwards. Especially if you listen to some of Stephen Halpern's Anti-Frantic music.

Bob

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The Answer
May 7, 2005 8:08PM PDT

Your friend contends that a copied sd is never as good as the original.
He is Wrong
You contend that the digital audio is just binary code.
You are wrong
Before "The Answer" I would like to say that this is a good discussion group I learned a lot.
Ok The Answer
They are both right
But.......... I rip lp's to cd's and mp3,s
etc and then produce a cd or dvd with a copy of the lp cover that I download
My audiophiles are delighted with the result

So ..The Answer
1. Rip you cd to a wav file
2. Use a wave editor (I use Cool Edit)
3.Learn the program and use noise reduction( I use it to remove hiss,clicks and pops from Lps"
4. Be aware that a wav file is big but once you have improved the quality you can burn to cd audio, dvd,mp3's whatever.
The Challenge send me a file and I'll send it back to all on this discusion group

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Audio File (no pun intended) !
May 8, 2005 12:14PM PDT

Hi,
I've put up Brazil by Xavier Cugat and his Orchestra from 1943. This is the music used in Terry Gilliam's film of the same name. It sounds suprisingly good having come from a '78. This is from a vinyl compilation copy of that called "Popular music of the 1940's". It's from my DJing days. I think Mr Gilliam actually used this version, because the quality actually sounds like a modern recording, which considering the gear they had in those days is pretty good.
This was recorded through an Audigy 2 sound card which has quite decent specs. This is the raw version without any noise reduction straight off my turntable.
I'd be interested to see how it comes out.
You can download it at:
http://www.sitezero.com.au/files/Brazil-Xavier_Cugat-1943.wav

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Arghhhhhhh
May 9, 2005 8:41PM PDT

Hi
Are you an Aussie ? (gumnut)
Tried to download a few times to no avail.
I ripped an 1950's Arthur Lyman Lp..Tabou for a mate,
Hiss cracle and pop on one dizk and cleaned on the other He loved both.
Btw way you can add needle and hiss sounds etc.
Is there another way to get your file ?

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Arghhhhhhh ?
May 9, 2005 10:33PM PDT
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Yes I am an Aussie...
May 10, 2005 1:49PM PDT

Sorry I only answered the last part of your post.
I was too busy sinking tinnies and shearing wombats to read the first part.
(We've gotta keep those yanks guessing!)

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Hearing the Difference
May 7, 2005 10:45PM PDT

There is no "basic" answer, but media brand and cd burning software/hardware aside, an exact digital copy is just as good as the original. It is what it is, an exact 'digital' copy. While some may argue this point, there are so many factors that weigh in to this it's impossible to explain this position to different people.

Does my copy sound better? What kind of system are you listening on? Most people cannot hear subtle differences in recorded media, but for those that can, any LP played on a high end turntable yields more presence than a commercial cd. An audio DVD approches this, mainly due to the higher sampling rate and frequency, but will most people notice? Higher bit rates in compressed media can sound better, but then you're approaching something that more resembles the uncompressed format and that defeats that purpose.

For those that can hear the difference between 16bit/44.1kHz and 16bit/48kHz, hats off! There is a lot of debate about whether or not the human ear can actually hear the difference of recorded media in the higher frequency ranges, but how do you explain to someone how it "feels" or the "presence" of the music which is totally subjective? All people perceive the same music differently, so it really is a matter of what pleases you.

In the end, if you are happy with what you hear, so be it and enjoy, For some people, even live music can have it's flaws! As for me, there are a lot of options for tweaking music to my taste, so that the music I 'get' may not be the music I listen to.

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Bravo !
May 8, 2005 11:16AM PDT

Exactly

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Another great answer above question below
May 8, 2005 3:57PM PDT

I have a CD of ELOs Out of the Blue. I hear the needle on this recording. And you know what? It sounds good. To me as good as the LP I wore out years ago. Admittedly my turntable wasn't a great one. It was probably a low side mid grade turntable.
But what I'm wondering if anyone else noticed this. If I remember right it's a remastered by Jeff Lyne recording. Did he do the needle sound? Or could it be some kind of pirated copy? I bought it at a major computer store. And yes presence was the word I was looking for earlier.
Why does a turntable sound better anyway?
Looks at scope...
Looks at spectrum analyzer....
Wishes I still had a turntable.
Remembers all the brushing and care of LPs
And yes that Stones album sounds strange without the pops and hisses. But worse overall? Not really to me.
later....

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To Sum It All Up
May 9, 2005 6:35PM PDT

If you are copying a digital source to digital eg MP3 or WMA to same then you are not going to loose quality - provided you do not reduce the bit rate.

If you select a too low level of bit rate for your digital source you will then notice loss of quality. After a bit of experimentation you should be able to decide on a format and bit rate that suits you.

If however you are recording from an analogue source eg your turntable/tape cassette/hi fi system then the old hi fi rules apply - it is the quality of the equipment and cabling that will impact on the quality of what you hear.

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RE: Fidelity of CD audio copies
May 10, 2005 12:07AM PDT

When copying cds at higher burn rates, especially 32x or higher, some data can be lost and cause a reduction in quality. This is especially true if non-audio (data only) discs are being used. If you stick to CD audio files, and audio discs, no sound quality difference will be heard even by the most serious of audiophiles as long as you use a medium to slow burn rate. However, ALL compressed files, such as MP3 files, have a very noticeable reduction in sound quality compared to the original cd audio recording. (A far more serious issue, and one that is too long for this discussion, is that recording engineers and producers think that listeners are morons, and only want LOUD recordings. They compress the recording by boosting lower volume sounds in the music to much higher levels, giving the overall volume a boost. This looses the artist's original meaning, as well as the emotions they intended to convey using music as their medium. If you like jazz, classical, or country music you dont have to put up with this reduction in sound quality very often, as those engineers still believe in letting the music convey emotions.)

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Re: RE Fidelity of CD audio copies
May 10, 2005 12:10AM PDT

Forgive me..... LOSES, not LOOSES. Geez, you fly to the east coast to train people and get up too early in the morning and post on here.......

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Thank you all for your responses...
May 12, 2005 4:08AM PDT

I now have a better understanding of the issues involved. I think the general concensus is that a copy is NOT a copy, and that there are many factors which can affect both the copying process and the playback of the recording. It seems that my co-worker was right after all. Thanks for all the great posts!

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A copy is a copy
May 12, 2005 6:41AM PDT

I know there are two different takes on this topic. However take it from someone who used to work in the music business.
A COPY IS A COPY!!!
Otherwise as many people pointed out, how would you ever expect a programme copied to a burnt CD ever to work. Even a tiny corruption in the data would affect it and stop it from installing. Copying to CD would be useless. The fact that we trust it for backing up data, tells us all we need to know about how it would also handle music data.