Pre-Emphasized Quake 1 Audio Question

[quote=Quakespasm-Music.txt]QuakeSpasm supports ogg, mp3 and wav external music files to be played
instead of cd music. What you should do is simple:

  1. Use your favorite cd-ripper application and rip your quake cdrom
    audio tracks, convert them to ogg or mp3 so they occupy less space,
    like track02.ogg, track03.ogg, etc.

    Note #1: There is no such thing as track01: the first tracks of
    original Quake and the mission pack cdroms are always data
    tracks.

    Note #2: Since the Quake cdrom audio tracks are pre-emphasized, you
    should de-emphasize them during or after ripping to make
    them sound right. (thanks to Sander van Dijk for this note)
    [/quote]

Has anyone here on Quaddicted done this for FLAC files and could he/she provide some steps as to how to do that? It would also make a great help page on this site for people who want to do this.

Using the sox command-line tool the synatx is:

sox input.flac output.flac deemph

for more info see: %url% (search for “deemph”)

What this does is reduce the treble a specific amount, to compensate for the treble being (supposedly) boosted when the CD was made.

I don’t own a CD copy of Quake, but I’m a bit skeptical. If the CD audio truly had the pre-emphasis filter applied it should sound noticeably wrong when played back without de-emphasis. Also note this bit from the sox manual:

Well, you say you have the flak files, probably ripped from the Cd.
In that case I would convert them back to wav files with the “formatfactory”. (freeware)
Now you have your wav files, dump them in the WaveEmphisizer,
and de-emphisize them to their original sound quality.

The emphisize programm you can find here:

http://home.kpn.nl/lo2kf8/WaveEmph.zip