1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.

    Dismiss Notice

How has redbook CD sound changed in the last 20 years...

Discussion in 'Music' started by redshifter, Sep 8, 2002.
First
 
Back
1
  1. gloco
    Quote:

    Originally posted by j-curve
    I don't agree in general with the idea that modern CD's are compressed at the studio.



    Um, go listen to linkin parks's hybrid theory album and Oasis' Whats the story morning glory, those are two prime examples of how bad a cd can sound when dynamically compressed. Sure, radio stations do it too because they have to. On the other hand i've heard countless live recordings done from radio broadcasts elsewhere and they sounded gorgeous.


    Quote:

    Originally posted by j-curve
    BTW gloco, I have a question for you re: ATRAC-R versus CD but I've decided to post it to
    this thread.



    I'll take a look. [​IMG]
     
  2. redshifter
    j-curve,
    i belive dynamic compression is done at the cd mastering point and at the radio station.

    Quote:

    As far as uncompressing a compressed CD, I think it is possible if the compression scheme has linear characteristics and you uncompress it in an equivalent way. This requires various assumptions plus some cooperation, so your chances are greatly reduced. An example of a reversible compression scheme is Dolby C for tape decks. In that case though, the problem is that if you playback without it you can hear the volume surging, so I never use Dolby C. The best way to compress without pumping or dropouts is to do it offline or to introduce some time delay, so that you know where the volume is going before you have to adjust for it. This makes for smoother shaping.



    an older compander scheme called dbx for cassette tape also does this, but imho is much more successful in the decoding step than dolby c. there seems to be less noise pumping with dbx and it also seems to warm the sound like atrac. of course dbx encoded tapes soundlike total crap unless you decode them. much worse than undecoded dolby c.

    if there was any standard in dynamic compression, decompressing the sound would be easy. i'm going to extract a .wav sample from "ok computer" and see if i can fix the dynamics use cool edit.
     
  3. gloco
    Quote:

    Originally posted by redshifter
    if there was any standard in dynamic compression, decompressing the sound would be easy. i'm going to extract a .wav sample from "ok computer" and see if i can fix the dynamics use cool edit.



    Cool, let us know what happens!
     
  4. redshifter
    i ripped 2 songs, airbag and electioneering. on electioneering i used a level over time graph on cooledit to see how things averaged out. it was like a ruler drawn across the peak levels, pretty sad. once the song got going the level was almost nailed at 0db.

    with cooledit's dynamic range processing i expanded the wave's range at levels -8 db or over. this seemed to be the point where the drum hits started peaking, but the more legato instruments had ended peaking. i set the expand ratio to 1.5:1, and adjusted the output gain to -1 db to compensate. the drum hit peaks lost that cut off by a ruler look. when i listened to the results, it was about 50% correct. the quiet intro to the some had some funny sounding dynamics in the slow attack synth notes. once the drums started, oh yeah. where before the song had that sharp cut-off in the drum dynamics, after expanding the drums had that punch i associate with vinyl, and older rock recordings. ideally i would need to do each instrument seperately, but at least in the drum rhytmic section it actually sounded not bad. it also showed me i would have to do each song differently, and different parts of the song with varying dynamic expansion. tomorow i'll upload a sample to this thread if anyone wants to check it out.
     
  5. redshifter
    i'll have to find a place to host these files, they're too large to attach.
     
  6. grinch
    Quote:

    Originally posted by redshifter
    i'll have to find a place to host these files, they're too large to attach.



    use a lossless compression on them and they'll be at least half of the current size. try monkeysaudio.com for a decent one.
     
  7. redshifter
    thanks grinch. even when i cut the .wav down to 6 seconds and saved it as a 128kbps .mp3 file it was still 10x too large to attach. at a compression large enough to fit it just sounded terrible.
     
  8. TheSonicTruth
    There are quality differences between mp3 and CD/wav, but dynamic compromise is not one of them. Data compression for the 7billionth time, does not affect dynamic range. Because 7billion seems to be the number of people on the planet who think data and dynamics compression are one and the same, SMH.
     
First
 
Back
1

Share This Page