CD Emphasis Control?

[Marc Hildebrant]

Group,

The red book CD standard allows for optional emphasis of the high frequency values. The cd players look for the emphasis indication and then "should" remove the extra boost.
Within the Diamond Cut software, is there a way of checking that the "ripped" wav file had any emphasis removed?

Marc

[Craig Maier]

That feature was rarely applied to red book CDs, so chances are very low that the pre-emphasis bit is set. To see if it is, just run the file through the spectrum analyzer and see if there is a bump up in the HF signals. When it was used, it was rare and not limited to one record/CD label. It mostly involved some pre 1985 CDs.

Craig

[Craig Maier]

If memory serves me well, only a few cds with pre-emphasis were released and it was in the mid 80s. The fix would be the use of the paragraphic EQ's top (shelving) band with the other bands shut off.

Craig

[Craig Maier]

The pre-emphasis was 50 uSec (3180 Hz) and shelving at 15 uSec (10,600 Hz). The de-emphasis are simply the reversal of the aforementioned curve (all yield first order slopes). I believe that produces a 10 dB amplitude boost in between those frequencies. This can be realized using the top two bands of the paragraphic EQ.

Craig

[Craig Maier]

I created a paragraphic EQ preset to reverse the early pre-emphasis found on some CDs.https://www.diamondcut.com/vforum/fo...rrection-curve

[Craig Maier]

The process would be to rip the CD in the same way as you would any other CD. If you know it has pre-emphasis, apply the de-emphasis curve found in the presets sharing section of the forum. It's a paragraphic EQ preset, version 9 and above.

[Craig Maier]

I found this list of CDs that were ostensibly recorded with pre-emphasis: https://studio-nibble.com/cd/index.p...elease_list%29

[Craig Maier]

I count a total of 171 titles almost all of which are 1985 or earlier.

Craig

[Craig Maier]

The latest version(s) of Diamond Cut Productions, Inc. software include this preset in the paragraphic EQ. This preset can be found in both the DCArt11 and the DCForensics11 programs.