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[Alex B]

I am re-ripping some of my old CDs. I stumbled on a thing called pre-emphasis. A few of those CDs obviously have pre-emphasis enabled. Does anybody know if pre-emphasis is taken care of somehow when audio CDs are ripped with a PC system: by hardware, by software or not at all?

Music Dictionary: Pre-Emphasis
A system for applying high frequency boost to a sound before processing so as to reduce the effect of noise. A corresponding de-emphasis process is required on playback so as to restore the original signal, and to attenuate any high frequency noise contributed by the recording process.

[GHammer]

That was mostly done on cassettes.
I'm not aware of this being done on CDs.

[Alex B]

They used to make pre-emphasis enabled CDs too. Mostly in the 80's. They are rare, but they exist. It is included in the Red Book standard. Stand-alone CD players aply de-emphasis if the pre-emphasis bit is detected on an Audio CD (at least most of them, some player manufacturers have forgotten that).

I found a table of the correction values in my archive:

Code: [Select]

The 15/50us pre-emphasis boosts as follows:

kHz 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
dB 0.0 0.0 0.0 0.1 0.1 0.1 0.2 0.2 0.3

kHz 1 2 3 4 5 6 7 8 9 10
dB 0.4 1.3 2.4 3.5 4.5 5.4 6.1 6.7 7.2 7.6

kHz 11 12 13 14 15 16 17 18 19 20
dB 8.0 8.2 8.5 8.7 8.9 9.0 9.2 9.3 9.4 9.5

[Alex B]

I googled a bit. Here's one of the search results, a longish discussion about pre/de-emphasis:

http://www.dsprelated.com/showmessage/2587/1.php

(Edit. I read through it. The discussion goes OT, but it starts with good information about the topic.)

[Alex B]

From: http://home.triad.rr.com/scottnixon/dac.htm

(= the "TubeDAC+ kit from Scott Nixon" page that was mentioned in this post: Re: Audiophiles: connecting your PC to the hi-fi?).

There is also, no de-emphasis filter either, so careful with those old Pink Floyd discs or other gems from the 80's.  IF they sound bright, they need to be eq'd a simple LED can be installed for visual notification, just don't play those disc or re-burn the disc with the eq applied.   I have ~500 CDs and 9 have pre-emphasis, nothing I've bought in the past 5 years have it.

[Krazykanuck]

If you are wondering why emphasis is there to begin with.

http://www.rogernichols.com/EQ/EQ-2003-07-08.htm.

[Alex B]

Thanks, that explains it more.

Actually, I would like to know if there is anything that I can do for those over bright CDs before adding the files to my MC library. I wonder if the correction could be done automatically by some software. One possibility could be to burn the ripped wave files with MC's DSP Equalizer and rerip.

My stand-alone CD player has the correction. I could also record the CDs with it. I suppose that the player can make the correction only when analog outputs are used.

[Krazykanuck]

De-emphasis is handled by the DAC.
Your standalone player most likely has a much higher quality DAC than that in your computer CD drive which is why it probably handles the CD better.
The problem with equilization is trying to get it right. You can probably get it to sound better but probably never quite right.
I think I saw in one of your other posts that you have a DMX6fire. If you can hook your CD player to it,  that may be your best bet.

[Alex B]

I have previously made this correction preset:



It works pretty well. The problem is that the EQ preset must be enabled manually when needed. It would help if MC could link EQ presets with files. Some rivals can do it.

[Krazykanuck]

The DMX6fire has an internal digital in, on the PCI card, so if your CD drive has a digital out you may be able to get the 6fire to do the deemphisis.
I hate suggesting things I haven't at least tried myself but I bought my 6fire when I started to convert vinyl.
If I am mistaken and you don't have a 6fire just ignore my ramblings.

[Alex B]

Yes, I have the DMX 6fire 24/96 on my main MC/HT PC. Actually, in my opinion it has a bit better DACs than my about 5-year old Sony stand-alone player.

I am not sure if it is de-emphasis capable. It is not mentioned anywhere in the documentation. Google found that another Terratec model has an option for de-emphasis in its own control panel, but DMX 6fire 24/96 doesn't have that.

I would like to trust the quality of MC's 32-bit DSP. I will first try to run the CDA image file through it and see if that works. Those CDs are not anything very high-end anyway. A simple treble reduction would be enough if it sounds OK in non-critical listening.

[modelmaker]

I have previously made this correction preset:



It works pretty well. The problem is that the EQ preset must be enabled manually when needed. It would help if MC could link EQ presets with files. Some rivals can do it.

Maybe version 12?