[ale] [OT] Help! burned cd playback wave clipped, original wave perfect

[Ron Frazier (ALE)]

Hi all,

I need some help with an audio cd production I'm working on for a 
private family event.  This is a little complex.

I've been working hard to pull some quality master audio waveform files 
from cassettes that I own.  The audio is as good as can be expected from 
a cassette tape, and is very decent to listen to.  I've worked hard to 
edit the files, set the levels, eliminate the clipping, and silence the 
space between songs.

I saved the MASTER files as signed 24 bit pcm wav files, which are 
lossless.  I then burn the wav files to cd (standard cd audio) using 
Windows Media Player.  Bear with me, this is NOT Windows centric.

Next I rip the cd I burned back to lossless wav files.  I then import 
the two waves, my master, and the ripped wave into audacity.  The waves 
look identical, as they should.

So, I know that my master wav file and the wave file on the cd, ripped 
back into wav are exactly the same.

Then I play the cd on a cd player and record back into audacity.  I make 
sure the volume on the input is NOT too high.  However, the waveform 
coming out of the cd headphone jack is visually severely distorted and 
clipped.

Look at this file.

https://dl.dropboxusercontent.com/u/9879631/cd_playback_clipping.png

The top waveform, titled ripped, is the file that was ripped from the 
cd.  It looks very nice and there is no clipping or excursions beyond 
the +/- 1 amplitude levels.  It's just like the master file.

The bottom file, titled played, is what was obtained by playing that 
same file (track) back and rerecording it.  Note that it is severely 
clipped, BUT, its excursions are nowhere near the +/- 1 limits.  This 
proves I don't have the input volume too loud.  This is something that's 
happening in the playback circuit of the cd player.  I've confirmed the 
behavior on 2 cd players and observed the same thing on a commercially 
recorded cd.

Also, I've compared the audio playing back the ripped file, versus the 
played file from the cd player.  The ripped version sounds better and 
fuller.

I wonder if they're doing some dynamic range compression on the output 
of the dac.  Whatever it is, it's not stored in the raw cd data.

Does anyone know what this is and if there is a way to eliminate this, 
so that the true waveform on the cd, which is the same as my master, is 
what comes out of the speakers.

Any help is appreciated.

Sincerely,

Ron


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Ron Frazier
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