Exactly. Here's the technical explanation...Engonoceras wrote: ↑Wed Jun 16, 2021 12:37 amCDs with pre-emphasis basically have greatly exaggerated treble. The purpose of this was they would cut the treble on playback supposedly reducing added CD Player decoding noise or something at the same time. The process was quickly abandoned because it just wasn't necessary after better D/A decoding came along.michael_charles wrote: ↑Tue Jun 15, 2021 6:08 pm So I have a question. Why does the pre-emphasis version have a higher DR value than the de-emph version?
"In the early stages of CD development, it was planned to make CD a 14 bit format and, even at the launch in 1982, most of the commercial digital to analogue converters were only 14 bit devices.
With only 14 bits resolution, quantisation errors on critical programme were perceptible and so the Red Book CD standard allowed for the inclusion of optional, analogue pre-emphasis of the signal prior to analogue to digital conversion with corresponding analogue, treble de-emphasis filter after conversion back to analogue in the player.
This technique raised the level of the treble modulation prior to the A to D converter to a point where the quantisation noise was a smaller proportion of the signal level, thereby improving linearity. And the de-emphasis in the player further reduced the audibility of the remaining quantisation errors by attenuating the high frequencies where they are most easy heard.
The presence of emphasis was signalled by a dedicated control bit in the recorded bitstream which the CD player detected and switched in the de-emphasis filter as required.
By the end of the 1980s, converters had improved enormously and were delivering a performance which rendered emphasis and de-emphasis obsolete and its use gradually fell out of fashion and favour."
Got that now? No? Okay I admit it...I don't understand all of that either! lol. But basically it was to do with players initially using 14bit ADCs.
The pre-emph curve is really simple...Engonoceras wrote: ↑Wed Jun 16, 2021 12:37 am A real shootout would be taking the Toshiba "Abbey Road" with emphasis intact, extracting one track (I suggest "Something") and then applying multiple "de-emphasis" plugins to produce multiple de-emph'd versions and see (a) what the differences actually are (b) what people prefer. I would do it but I don't have the time and don't want to track down plug-ins.
There is the SoX plugin
http://sox.sourceforge.net/
There is "IIR filter" that will work with Foobar. You select the filter with the option "CD De-Emphasis" selection.
There's also an Audacity plugin. In the old days may have been a VST plugin.
I did my de-emph conversion years ago but I forgot what plugin I used it may have been one of those or something different.
Really simple for a computer programme to reverse engineer accurately and so there's not really any latitude for differences in the decoding by different plug-in's.
P.S: Your link for sox is just the homepage for the sox project...not a link to a de-emph plug-in.