CD fidelity

Discussion in 'General Hardware' started by Taurus, Dec 23, 2002.

  1. Taurus

    Taurus hardware monkey

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    i remember reading somewhere a while back that burning cd's at a higher speed will cause the 1's and 0's to be less defined. but as long as the player/drive can read them it shouldn't matter, right?

    what i'm trying to get at is someone is trying to tell me that if you burn an audio cd at a lower speed (say, 2x) then you will get better sound quality. doesn't quite make sense to me since it's digital.. but i remember reading that factoid a long time ago so i'm wondering if there's any truth to his claim..?
     
  2. dreamliner77

    dreamliner77 The Analog Kid

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    The logic goes that a pressed cd has a certain fidelity because the lands and pits are physically pressed into the aluminum layer. Now, with cdr, the lands and pits are made optically with a laser; not true lands and pits. It has been theorized that as the burning speed increases, the definition of the lands and pits is smeared. Whether this is really true has yet to be seen. It is kinda like the vinyl lovers that claim to hear the space between the samples in digital audio.

    There are some drives that try to circumvent this. Plextor has a drive that allows you to adjust the laser intensity. Yamaha has drives with an audio mastering mode. They add more space between the spiral data track so it can be more defined and lower the burning speed to 4X I believe. But now you only get aproximately 64 min on a 80 min cdr.

    Some people will only ever burn audio at lower speeds. Personally, I've always burned at 12x (the max of my drive) and never had a problem unless I caused it.

    It is my belief that it is not really speed that is an issue. It is more about the media, burner and software.

    1) use good software (Nero, Feurio, GoldenHawk's CDRwin, etc--- Stay away from Easy CD Creator)

    2) Use good quality cdr's: Taiyo Yuden, Mitsui, Ritek, Kodak etc. Stay away from cheap bargain buys: Imation, Memorex, Best Buy, Circuit City, etc

    3) Use a good drive. LG, Lite-on, Plextor.

    Some drives like some discs better than others.

    And do we really need all this high speed? First of all, there is no agreed standard for measuring burn speed. Second, we're only talking about seconds here.

    Also, some people think that burnproof screws up audio cd's. The logic sounds good to me, but I can't say since I don't have a drive with burnproof (or smartdisc or whatever). So I'd suggest you just go without burnproof for audio cd's.


    Also, Many drives suffer more errors when they burn at a speed other than their maximum.

    Just some stuff to think about...
     
  3. djwhite

    djwhite OSNN Senior Addict

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    I burned some music on my Lite-On burner at 32x with burnproof (or whatever Lite-On uses) enabled on Laser CD's (cheap but reasonable quality), then I burnt the same tracks at 2x on a Kodak CD, and when it finally finished, I listened to both and I couldn't tell the difference between them. Just thought you might like to know that.
     
  4. Zedric

    Zedric NTFS Guru Folding Team

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    If you run at high speed the "gaps" will be less defined. =>
    The CD-player will read more of them wrong. =>
    The sound will get more "messed up" than usual, but maybe not enough to skip. After filtering it will sound closer to normal. =>
    Worse quality then it should be.

    (Oh, btw, a pressed CD is pressed in the plastic. The aluminum is sprayed on top later.)
     
  5. Taurus

    Taurus hardware monkey

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    thanks for your input, guys. after what i originally thought and you had to add, i'm going to reason that the speed at which you burn an audio cd doesn't affect the analog output quality.

    after all, if a 'pit' isn't read right, you should hear an audible pop or crack during the song. simply having smeared digital pits (eww.. lol) shouldn't make the analog output sound muddy or have any loss of quality, as long as the drive/player can read all the pits.
     
  6. dreamliner77

    dreamliner77 The Analog Kid

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    Taurus,

    That's not neccesarily true. If the pits are "smeared". It could very likely lead to a much more reduced lifespan of the disc.

    What kind of drive to you have?
     
  7. djwhite

    djwhite OSNN Senior Addict

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    It's in his sig;)
     
  8. Luna64

    Luna64 Guest

    That is not really true.

    If you burn music to a 48 x CD at 1x, it will sound worse then if you burned at 48x. Why ? Because the CD is designed for High Speed, not for low speed. The media itself is ment to be burned at 48x, not 1x. But don't get me wrong, I am not positive on this. Just going from what I have been told from an Audiophile.

    www.cdrinfo.com might clear that up for you


    :huh:
     
  9. Zedric

    Zedric NTFS Guru Folding Team

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    Ah, but you are wrong my friend. A CD-player has a filter which reduces these pops. Playing any CD without the filter would sound like sh*t to be honest*. There is no way to guarantee the correct reading of all bits, and therefore you have these filters. If more of the pits get read wrong these filters will start to "loose grip" and the quality will get (at least slightly) worse. If enough pits get read wrong the player will begin to skip.

    *This is a popular demonstration in CD-Audio and digital storage classes.
     
  10. dreamliner77

    dreamliner77 The Analog Kid

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    Best way to answer this.

    Burn a bunch of cd's with different option and then run speeddisk and see how many errors each disk has
     
  11. Taurus

    Taurus hardware monkey

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    so, zedric and dreamliner...

    i've never heard of these 'filters' that zedric speaks of, but i'll take his word for it. BUT... if a burned audio cd really does have small errors on it (messed up bits), then why are data cd's burned at 48x just fine? there would most certainly be unreadable files and such if what you said was true..?
     
  12. dreamliner77

    dreamliner77 The Analog Kid

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    Data cd's have way more built in error correction than audio cd's. That's why you can only burn 700mb of data on a cd that will hold 800mb of audio.
     
  13. Zedric

    Zedric NTFS Guru Folding Team

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    Yep, since data is way more sensitive than audio (you can't filter away bad data) there is error correction.
     
  14. Duke Zootin

    Duke Zootin Guest

    I finally registered, I couldn't resist this thread !! I'm a long time reader of this site, first time poster !! :D



    Anyway, to the issue:

    This topic is something that's caused great debate over the past few years. As usual, most of this debate is rooted in what people "think" they hear, or what makes sense to them, instead of actual testing and facts. It usually boils down to those that have "The Golden ears" ears and those that don't. (No offence to anybody here that may possess such a set of ears)

    Here's a fact - The only real thing will cause deviations in the sound quality of cd's are the number of errors on the cd. Either the player can read a valid 1 or 0, or it can't. All cd's contain errors, even pressed ones. CD players attempt to 'fill in the blank" when it encounters an error. The more blanks it needs to fill in, the higher the potential for it to effect audio quality.

    Talk about pit/land leading/trailing edges not defined well enough in burned cd's are pointless, it's still about error's. If the pit/land isn't well defined, but the player can still properly determine it's a 1 or 0, then it doesn't matter since the data is valid and correct. If a pit/land isn't defined properly, and can't be determined, either because of burning, media choice or software used, it still becomes an error. So, let's focus on that.

    So, the there are two factors at work here, the number of errors on a cd, and the cd players ability to overcome these errors. The former we will get to in a second, the latter is wholly dependant on your hardware/equipment.

    So, we need to see some actual test measurements on errors generated by burning at different speeds. It just so happens that people have actually done these tests to find out the truth. Go have a look here:

    http://www.emedialive.com/EM2000/starrett5.html

    I think that pretty much speaks for itself, so I won't summarize much other to say that it's clear that using quality hardware and media, the number of errors at higher burning speeds aren't any more than at lower speeds, and in some cases higher speeds generated fewer errors since the burner was designed to operate at higher speeds.


    I'd also like to raise a few more points -
    First, What kind of music are you burning exactly ? If you are making cd's from MP3 files then it's really a moot point since the audio has already taken a huge fidelity hit in the MP3 conversion process.
    Second, What are you playing these back on ? If it's your PC or average/generic home stereo, you probably aren't going to tell the difference either since 'average joe' home stereo's and PC speakers have anything but a flat frequency response and color the sound anyway (sometimes in a way we personally like, but not always).
    Lastly, and most important, does it sound ok to you ?? After all, you are the one listening to it. Do you like what you hear ? You are what really counts in all this. If you enjoy what you are hearing, and can't "hear" the difference between different burn speeds then you might as well burn at the highest your hardware supports.

    Me, I burn at 12x (fastest for my burner) :)


    Regards,
    Dukey