Page 3 of 3 FirstFirst 123
Results 31 to 45 of 45

Thread: Dealing with CD pre-emphasis

  1. #31
    Senior Member Merl's Avatar
    Join Date
    Jul 2016
    Location
    Scotland
    Posts
    3,587
    Post Thanks / Like

    Default

    Quote Originally Posted by Kiki View Post
    Do you rip your CDs, Merl? Some early CDs are pre-emphasis coded, meaning that the upper range of the audio signal is boosted. CD players will de-emphasize such a signal to normal for playback, so you won't be aware of it at all. But when we rippers (just want to say this word) rip such a CD image using a computer drive, the signal in the image is still pre-emphasis coded, so we need to de-emphasize the signal using a tool like SoX, otherwise the music will sound "brighter" than it should.

    It's suggested that if iTunes is used to rip such a CD, iTunes would de-emphasize the audio signal automatically. I have no idea if that is the case.
    Thanks Kiki, I did get the gist of this but it's nice to have someone summarise it so well. I'd never heard of it before. Was pre-emphasis on all discs (regardless of genre)? I'd never heard of it before now.
    Last edited by Merl; Nov-25-2018 at 09:58.

  2. Likes Kiki liked this post
  3. #32
    Senior Member bigshot's Avatar
    Join Date
    Nov 2011
    Location
    Hollywood U.S.A.
    Posts
    5,879
    Post Thanks / Like
    Blog Entries
    1

    Default

    I don't understand why ripping software doesn't just apply the compensation as they rip. If it's a transparent process on playback, why isn't the same for ripping? I use iTunes and I've never noticed anything like this, so I'm guessing it handles the preemphasis flag properly
    CD Sound Is All You Need: http://xiph.org/~xiphmont/demo/neil-young.html
    AES Audio Myths Seminar: http://youtu.be/BYTlN6wjcvQ
    AES Damn Lies Seminar: http://youtu.be/Zvireu2SGZM

  4. #33
    Senior Member Baron Scarpia's Avatar
    Join Date
    Jun 2018
    Location
    California
    Posts
    1,242
    Post Thanks / Like

    Default

    Quote Originally Posted by bigshot View Post
    I don't understand why ripping software doesn't just apply the compensation as they rip. If it's a transparent process on playback, why isn't the same for ripping? I use iTunes and I've never noticed anything like this, so I'm guessing it handles the preemphasis flag properly
    iTunes does. EAC is too obsessed with "bit perfect" to do anything so practicel.

  5. #34
    Senior Member Kiki's Avatar
    Join Date
    Aug 2018
    Posts
    399
    Post Thanks / Like

    Default

    Quote Originally Posted by Merl View Post
    Thanks Kiki, I did get the gist of this but it's nice to have someone summarise it so well. I'd never heard of it before. Was pre-emphasis on all discs (regardless of genre)? I'd never heard of it before now.
    Mainly found on CDs made in the early 80s. It is not a genre thing, although BIS, for example, is known to hang on to pre-emphasis coding well into at least the early 90s. My BIS CDs made around that time are all pre-emphasis coded.

  6. #35
    Senior Member Kiki's Avatar
    Join Date
    Aug 2018
    Posts
    399
    Post Thanks / Like

    Default

    Quote Originally Posted by Baron Scarpia View Post
    Ok, sox works just fine on Mac and I can deal with pre-emphasis with no problems, if I know it's there.

    Here's a new dilemma. Downloaded FLAC files for an old BIS release from Presto Classical. BIS CD-458, Kokkonen string quartets. The CD is from an era when BIS was commonly using pre-emphasis. The FLAC files sound a bit bright to me. Could it be that whoever generated those FLAC files didn't realize that there was pre-emphasis that would have to be removed? Or is that just how the recording sounds?

    Looks like I'm going to order a used copy of the CD to get a definitive answer.

    The moral of the story, don't buy any downloads of a source that might or might not have pre-emphasis.

    (Is there a database somewhere of CD releases with pre-emphasis?)
    This should be entered into the 101 Horror Tales for Music Lovers... I can imagine how annoying it is. Is it the recording, or is it pre-emphasis? I wouldn't be too surprised if it were a mistake. But to find out for certain, like you said, better go get a used CD if it's not too expensive. I doubt there is any decent pre-emphasis database out there. Google points to a few obviously incomplete lists, but then they don't include classical CDs either.

    Glad to know SoX on Mac works fine for you!

  7. #36
    Senior Member jegreenwood's Avatar
    Join Date
    Dec 2015
    Location
    NYC
    Posts
    1,957
    Post Thanks / Like

    Default

    Quote Originally Posted by Kiki View Post
    Mainly found on CDs made in the early 80s. It is not a genre thing, although BIS, for example, is known to hang on to pre-emphasis coding well into at least the early 90s. My BIS CDs made around that time are all pre-emphasis coded.
    I guess I was lucky. I was an early CD adopter. But until about 4 years ago my ripping was done with iTunes. (I now use JRiver.)

  8. Likes Kiki liked this post
  9. #37
    Senior Member Baron Scarpia's Avatar
    Join Date
    Jun 2018
    Location
    California
    Posts
    1,242
    Post Thanks / Like

    Default

    Quote Originally Posted by Kiki View Post
    This should be entered into the 101 Horror Tales for Music Lovers... I can imagine how annoying it is. Is it the recording, or is it pre-emphasis? I wouldn't be too surprised if it were a mistake. But to find out for certain, like you said, better go get a used CD if it's not too expensive. I doubt there is any decent pre-emphasis database out there. Google points to a few obviously incomplete lists, but then they don't include classical CDs either.

    Glad to know SoX on Mac works fine for you!
    I applied deemphasis to the download (BIS CD-458), and found another BIS recording of string quartet on my hard drive that has pre-emphasis (Nielsen string quartets, BIS CD-503). Compared the download with and without application of deemphasis to the old CD (CD-508) with and without application of deemphasis. The raw version of the download seems more similar to the raw version of CD-503 and the processed version of the download seems more similar to the processed version of CD-503. Based on that I suspect the FLAC file I downloaded has uncorrected pre-emphasis. To further confuse matters, I invested $0.99 and bought one track of the CD as an MP3 from Amazon. It sounded identical to the raw version of the download. If I'm right the FLAC file I downloaded and the MP3 version amazon is selling are audio files with uncorrected pre-emphasis. Hard to say for sure, maybe the recording is just brighter than I prefer.

    I bought a used copy for four bucks. When it arrives, I'll rip it and see what is what. That's the only way it will ever be resolved.

    If it turns out that Presto sold me a file with uncorrected pre-emphasis, maybe I'll have a go at asking for a refund. In the past their customer service has been good.
    Last edited by Baron Scarpia; Nov-26-2018 at 21:19.

  10. Likes Kiki liked this post
  11. #38
    Senior Member Kiki's Avatar
    Join Date
    Aug 2018
    Posts
    399
    Post Thanks / Like

    Default

    Quote Originally Posted by Baron Scarpia View Post
    .... I bought a used copy for four bucks. When it arrives, I'll rip it and see what is what. That's the only way it will ever be resolved.
    Awaiting your test results! $4 is certainly worth spending for getting to the bottom of this!

  12. #39
    Senior Member Baron Scarpia's Avatar
    Join Date
    Jun 2018
    Location
    California
    Posts
    1,242
    Post Thanks / Like

    Default

    Quote Originally Posted by Kiki View Post
    Awaiting your test results! $4 is certainly worth spending for getting to the bottom of this!
    It's percolating through the US postal service as we speak, a 3,000 mile journey.

  13. Likes Kiki liked this post
  14. #40
    Senior Member Baron Scarpia's Avatar
    Join Date
    Jun 2018
    Location
    California
    Posts
    1,242
    Post Thanks / Like

    Default

    Quote Originally Posted by Baron Scarpia View Post
    It's percolating through the US postal service as we speak, a 3,000 mile journey.
    New tracking result, it is within 200 miles of my location.

  15. #41
    Senior Member Baron Scarpia's Avatar
    Join Date
    Jun 2018
    Location
    California
    Posts
    1,242
    Post Thanks / Like

    Default

    The CD arrived, I ripped it, it had the pre-emphasis flag set, and I applied de-emphasis with Sox.

    Did a listening comparison with the FLAC downloads from Presto. The raw CD rip sounds like the raw FLAC download, an artificially sizzle on the treble. The CD with deemphasis applied sounds like the FLAC download with deemphasis applied.

    The conclusion seems to be that Presto was distributing a raw disc image with uncorrected preemphasis.

    I also compared the amazon MP3 download, which sounded like the presto FLAC download. Both Amazon and Presto seem to have made the same mistake. That suggests the error might trace back to BIS.

    I sent an email to BIS.
    Last edited by Baron Scarpia; Dec-05-2018 at 08:55.

  16. Likes Kiki liked this post
  17. #42
    Senior Member Kiki's Avatar
    Join Date
    Aug 2018
    Posts
    399
    Post Thanks / Like

    Default

    That's pretty much conclusive! Thanks for your test results!

    Ahhhhhh, really need to stay wary of digital downloads of old masterings.

    Will be interested to know what BIS has to say about this!
    Last edited by Kiki; Dec-05-2018 at 14:08.

  18. #43
    Senior Member Baron Scarpia's Avatar
    Join Date
    Jun 2018
    Location
    California
    Posts
    1,242
    Post Thanks / Like

    Default

    I've been remiss in not posting what BIS had to say about this. I got this reply the day after I sent them a query:

    Dear Mr. LaPorta,

    this issue isn't unknown to us, and we are - slowly but surely - trying to take care of it. When there were only CD:s and that generation of players (we're talking the late '80:s of early 90's here), this wasn't a problem, since those players had an automatic de-emphasis function. That seems to no longer be the case, but I believe we're on tio it.

    I am copying Matthias Spitzbarth with this, since he is the one that occupies himself with these questions.

    Thanl you for your very nice words and your interest - and, of course, your custom. Maybe it would make sence to use our own down-loading site eClassical.com? Cheaper and better than most.

    Best - Robert (von Bahr, CEIO, BIS and eClassical)
    More or less the best one can expect, but the answer is that they are still trying to sort it out. Clearly I will not be downloading any FLAC files from releases that might have pre-emphasis.

  19. Likes Kiki liked this post
  20. #44
    Senior Member Kiki's Avatar
    Join Date
    Aug 2018
    Posts
    399
    Post Thanks / Like

    Default

    Thanks for posting the reply from BIS. Well at least they admit there is an issue, but like you said I would stay away from buying downloads of early digital recordings.

    I didn't know eClassical belonged to BIS. One annoying thing about eClassical is that they don't always state the sampling rate for their hi-res downloads, so I seldom bought from them.

  21. #45
    Senior Member bigshot's Avatar
    Join Date
    Nov 2011
    Location
    Hollywood U.S.A.
    Posts
    5,879
    Post Thanks / Like
    Blog Entries
    1

    Default

    They should just rip with iTunes.
    CD Sound Is All You Need: http://xiph.org/~xiphmont/demo/neil-young.html
    AES Audio Myths Seminar: http://youtu.be/BYTlN6wjcvQ
    AES Damn Lies Seminar: http://youtu.be/Zvireu2SGZM

Page 3 of 3 FirstFirst 123

Similar Threads

  1. Are there cds dealing with Codex modena or codex modena b
    By deprofundis in forum Classical Music Discussion
    Replies: 3
    Last Post: Mar-29-2016, 12:42

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •