A while ago all of my CD's were ripped to flac on a server. The process was of course slow, but there was no apparent problems during this process.

After a while I was surprised at how thin the sound was on some of the music, but since it was mostly older recordings I had an idea that it might be correct. The problem was of course that Iin my memory some of this music didn't sound thin, like e.g. The Wall. After some research I found this article: http://en.wikipedia.org/wiki/De-emphasis. With this EQ curve http://www.stevehoffman.tv/forums/ar...p/t-88541.html loaded into Audacity I equalized a few tracks. The music was again usable.

It seems that ripping and de-emphasis is not always good friends.
  • Some of the computer drives don't recognize the pre-emphasis bit
  • some of the ripping software don't have de-emphasis
  • finally if you manage to keep the pre-emphasis setting, the new media-player / dac might not recognize it.
In this process I also changed from running a CD-player with the internal DAC to a Squeezebox with an external DAC.

I have studied the CD's with pre-emphasis, but haven't found any signs that the CD's have been treated this way.