Audio CD burning: Speed and quality
Nils Holland
Some time ago there was a thread here which dealt with burning audio CDs. I
said, that I observed that burning CDs fater than 1x often caused problems
when these CDs were later played back on certain (especially Sony)
CD-Players. Others could not confirm this relationship between burn-speed
and quality (compatibility?) of CDs. Now, I have done some experiments and
would probably like to hear some comments.
I did the following: I took a normal pressed CD and read it out in my
CD-ROM drive using a Linux-program called cdparanoia. That program is
optimized for good reading results even with cheap CD-ROM drives and
dirty/scratchy source disks. Furthermore, that software displays status
inofmration about when during the read process it encountered problems
(which it can correct most of the time, but it still tells the users that
problems occured).
So, as I said, I read out an original CD using that software and I received
no information about errors. Then, I burned what I had read out using my
CD-writer to two CDs of the same make and model. One CD was burned at 2x
and one at 12x (the highest speed my writer supports).
Playing back these CDs on an orinary CD players worked fine, without
problems. However, I decided to read out my burned CD with cdparanoia
again. With the 2x speed burned CD, there were, like with the original CD,
no errors. The 12x burned CD did, however, show 4 errors, all of shich
could be corrected by the software.
This does somehow seem to suggest a relationship between burn speed and
quality of the burned CD. Probably some CD-players would even have had
problems reading my 12x burned CD, like I said I actually observed in the
thread a few months back here.
So ... any comments on this? Has anyone seen any *real world* evidence of a
link between burn-speed and quality of the burned CD?
Greetings
Nils
--
----------------------------------------------------------
Nils Holland - ni...@nightcastleproductions.org
NightCastle Productions - Linux in Tiddische, Germany
http://www.nightcastleproductions.org
"Give the heavens above more than just a passing glance
And when you get the choice to sit it out or dance -
I hope you dance!"
----------------------------------------------------------
Sam Goldwasser
1X and 12X. :)
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JURB6006
ago. I've learned a few things, and logic dictates that it leads to more. . . .
.
To burn a CD faster means you need a more powerful laser with better transient
response. (better frequency response)
This is mainly because the time the laser has to act upon any given part of the
CD is shorter. It is concievable that there is a difference in the error rate,
but that equates to almost nothing on an audio CD. At any rate four correctable
erors doesn't sound too bad, given the fact that 12X is fairly new. The disks
also matter, they are somewhat analoguous to photographic film in terms of
quality, even though they do not work in exactly the same manner. The very old
film was slow, you used to have to sit still to have your picture taken, now
you can be riding in a jet at mach 1 and be "frozen in time" by the shutter and
the film will respond, because it is faster. I think the same reasoning applies
here, although I don't understand the limiting mechanism, is it the response of
the laser or the power ?, or both ? If you had a very powerful very fast laser,
would the limiting factor be the heat produced in the media during burning ?
i.e. actually deforming the vehicle (which in this case is the clear plastic
body of the CD) get what I mean ?, , , if you heat the disk so much there is a
tiny warp in it screwing up the adjacent tracks. . . .
Every time I find an answer I find at least a dozen questions. In short I would
say to burn important data CDs at lower speeds, because the correction of the
audio is so much easier, more than ½ of it is done in the analog domain, this
is because we can only hear so much and if all else fails, it can always mute
the output. Data CDs are a whole different story, if you have a program with
errors, the results could be disastrous.
There is one other advantage to burning slower, especially if you are not in a
hurry. It wears everything out more slowly. Even the lasers in audio CD players
wear out, although they shouldn't, but they do. Burning faster has got to mean
using a higher power level, and that means more heat. I think if time isn't
critical, even if I had a 12X, many a time I might burn at a slower rate.
There's no sales tax on that 2 cents :)
CLSNOWYOWL
tried it at 1x, 2x, 4x, and higher speeds. i have found the 4x write speed
works best, as most ordinary cd players have 4x oversampling (part of disk
verification process during read), so there are a number of factors that seem
to take place here to make a good quality CD that writes when it should and
accurately, so that it will read accurately.
these factors are: speeds the CD media can actually be written at. Some CD-R's
can only be written up to 4x, some have variable write speeds that work. The
reflectivity of the CD media makes a difference. the lighter the dye colors on
the CD-R actually are, the better the burn, due to the way the light is
reflected off of the disk during read and burned on during disk recording or
writing. The variance of the writeable drive on write speeds makes a
difference. The sampling frequency used to burn a CD makes a difference. The
kind of information (data or audio) placed onto a CD makes a difference, as
does track layout.
even details like disk at once mode, make a difference also. I have had disks
that have had an incorrect layout, producing a poor result in this manner. For
example, I have had disks that recorded part of track 2 at the end of track
one.
Copyability of the original source CD being read from is an extremely critical
factor, as are other imperfections on the recordable CD. Also, CD-R format
makes a big difference in how the track spacing and widths are made upon a
burn. pro-CD's use less spacing than a consumer CD, due to the laser's
angularity.
The software you use, the operating system you use, all of the hardware and
memory features of the computer system and the audio card you use make a big
difference in how a burned CD actually writes, due to all of the algorithms and
processes that take place to perform the signal process functions in order to
achieve the correct signal level, formula, and data accuracy to make the burn
onto the CD.
These are just some of the things i have found when using a CD burner. I am
only expressing my findings based upon the experiences others have had, the
articles I have read in sound and Vision magazine on the subect, and my own
actual personal experiences. I realize this technology is still relatively new
and my opinions and personal experiences are subject to attack, but I have
actually found that there are slight but audible differences when T record the
CD-R's at different speeds. The cleanest playback and sound occurred for me at
4x upon burn and the CD's have been readable in every CD player I have ever
owned, including my old sony portable CD player, which read my CD-R's just
fine. I use some of these disk to test other people's CD players when I test
them after performing repair on them and I have never had a complaint about it.
Charles Lucas
Subject: Audio CD burning: Speed and quality
From: Nils Holland ni...@nightcastleproductions.org
Date: 6/21/01 2:30 PM EST
Message-id: <33itg9...@cynthia.ncptiddische.net>
Tom MacIntyre
wrote:
>I have burned about 100 CD's in the last couple of years for audio. I have
>tried it at 1x, 2x, 4x, and higher speeds. i have found the 4x write speed
>works best, as most ordinary cd players have 4x oversampling (part of disk
>verification process during read)
???
Sam Goldwasser
> I have burned about 100 CD's in the last couple of years for audio. I have
> tried it at 1x, 2x, 4x, and higher speeds. i have found the 4x write speed
> works best, as most ordinary cd players have 4x oversampling (part of disk
> verification process during read), so there are a number of factors that seem
> to take place here to make a good quality CD that writes when it should and
> accurately, so that it will read accurately.
Not questioning your conclusions or results, but 4X oversampling has absolutely
nothing in common with 4X write speed - they are totally independent specs.
It's a coincidence if that happens to be best. :)
Leif N
<20010624021620...@ng-ca1.aol.com>...
[....]
>these factors are: speeds the CD media can actually be written at. Some CD-R's
>can only be written up to 4x, some have variable write speeds that work. The
>reflectivity of the CD media makes a difference.
The reflectivity of a cdr is not interesting, the absorption is. The dye
color on the disc is supposed to absorb the color of the cd players laser,
that's a big reason why some cdr's disc plays flawless, and some performs
terrible - the color is not aborbing enough.
the lighter the dye colors on
>the CD-R actually are, the better the burn, due to the way the light is
>reflected off of the disk during read and burned on during disk recording or
>writing. The variance of the writeable drive on write speeds makes a
>difference. The sampling frequency used to burn a CD makes a difference.
Eh.. ? A CD can only be 44.1Khz/16bits, otherways the cdplayer will reject
it.
The
>kind of information (data or audio) placed onto a CD makes a difference, as
>does track layout.
>
>even details like disk at once mode, make a difference also. I have had disks
>that have had an incorrect layout, producing a poor result in this manner. For
>example, I have had disks that recorded part of track 2 at the end of track
>one.
>
>Copyability of the original source CD being read from is an extremely critical
>factor, as are other imperfections on the recordable CD. Also, CD-R format
>makes a big difference in how the track spacing and widths are made upon a
>burn. pro-CD's use less spacing than a consumer CD, due to the laser's
>angularity.
>
What's a "pro-CD" ?
>The software you use, the operating system you use, all of the hardware and
>memory features of the computer system and the audio card you use make a big
>difference in how a burned CD actually writes, due to all of the algorithms and
>processes that take place to perform the signal process functions in order to
>achieve the correct signal level, formula, and data accuracy to make the burn
>onto the CD.
>
A computers configuration (slow cpu, not enough memory) can cause a "buffer
underrun", besides that, I doubt the configuration has much to say. If you
use a unit with "burnproof" (Plextor among others) buffer underrun doesn't
matter, the burning pauses until enough resorces are available again.
--
Leif Nordland
''''
Seventeen days? Look man, I don't wanna rain on your parade,
but we're not gonna last seventeen hours!
CLSNOWYOWL
stand-alone CD-R writers will not actually take a data CD-R (also identifed by
these machines as a "pro-CD").
On a consumer type of CD-R, here in the U.S., the consumer has paid a royalty
tax on the purchase of a consumer CD-R format (I.e. TDK brand, among others),
where with a data CD, the cost is lower and no royalty is paid. The data CD-R
will not write on any machine, but the consumer audio CD-R will write on any
machine.
Charles Lucas
Subject: Re: Audio CD burning: Speed and quality
From: "Leif N" myr...@online.no
Date: 6/24/01 8:52 AM EST
Message-id: <9h57pt$c5vle$1...@ID-11876.news.dfncis.de>
Leif N
<20010626163235...@ng-ci1.aol.com>...
>A Pro-CD is a high grade format of CD that is usually used for computers. Some
>stand-alone CD-R writers will not actually take a data CD-R (also identifed by
>these machines as a "pro-CD").
>
>On a consumer type of CD-R, here in the U.S., the consumer has paid a royalty
>tax on the purchase of a consumer CD-R format (I.e. TDK brand, among others),
>where with a data CD, the cost is lower and no royalty is paid. The data CD-R
>will not write on any machine, but the consumer audio CD-R will write on any
>machine.
Where did you hear that ? To my knowledge there is no difference betw these
"Audio CD's" and Data CD's in terms of quality, The only difference is the
standalone ones refuse to write on dataCD's cuz they don't have the right
"code" of some sort. The royalty doesn't make the discs better, it only
feeds the greedy ppl !
We have royalties on those discs here too (Norway), I've seen prices up to
10x that of datacd's... They won't get my money.
CLSNOWYOWL
based upon what CD writers will read and will not read. See the November, 1998
issue of Stereo Review (sound and Vision) magazine which talks in detail about
these format differences. The differences in format do NOT affect the sound
quality, the affect the capability for either one player to either write or not
write information to teh disk, depending on the format you use.
http;//www.soundandvision.com
Charles Lucas
Mike reverse the letters S.
In article <20010624021620...@ng-ca1.aol.com>,
CLSNOWYOWL <clsno...@aol.comjoe345> wrote:
>I have burned about 100 CD's in the last couple of years for audio. I have
>tried it at 1x, 2x, 4x, and higher speeds. i have found the 4x write speed
>works best, as most ordinary cd players have 4x oversampling (part of disk
>verification process during read), so there are a number of factors that seem
>to take place here to make a good quality CD that writes when it should and
>accurately, so that it will read accurately.
Are you equating 4x oversampling with 4x write speed? These values have
nothing to do with each other.
>these factors are: speeds the CD media can actually be written at. Some CD-R's
>can only be written up to 4x, some have variable write speeds that work. The
>reflectivity of the CD media makes a difference. the lighter the dye colors on
>the CD-R actually are, the better the burn, due to the way the light is
>reflected off of the disk during read and burned on during disk recording or
>writing.
The relative "lightness" of dyes in different CDR's is an artifact of
their absorption of visible light. Under the infrared light of a CD pickup
laser, they look altogether different.
>Copyability of the original source CD being read from is an extremely critical
>factor, as are other imperfections on the recordable CD. Also, CD-R format
>makes a big difference in how the track spacing and widths are made upon a
>burn. pro-CD's use less spacing than a consumer CD, due to the laser's
>angularity.
Are you referring to the difference between "consumer audio" and data
grade CDR's? The only difference is a byte in the ATIP information in the
progroove (the Disc Application Code) which identifies each disc's
intended use.
http://groups.google.com/groups?oi=djq&ic=1&selm=an_644736110
http://users.forthnet.gr/ath/axatis/FAQs/CDR/Media/audio.htm
The.Central.Scru...@invalid.pobox.com
>In article <20010624021620...@ng-ca1.aol.com>,
>CLSNOWYOWL <clsno...@aol.comjoe345> wrote:
>>I have burned about 100 CD's in the last couple of years for audio. I have
>>tried it at 1x, 2x, 4x, and higher speeds. i have found the 4x write speed
>>works best, as most ordinary cd players have 4x oversampling (part of disk
>>verification process during read), so there are a number of factors that seem
>>to take place here to make a good quality CD that writes when it should and
>>accurately, so that it will read accurately.
Oversampling has nothing to do with reading the disc. Oversampling is
interpolation between data points where the DAC is run at a higher rate.