CD pre-emphasis/de-emphasis

In ripping around 2000 CDs over the past two years, I had not to my knowledge come across any CDs mastered with pre-emphasis – until this week, when I randomly hit the jackpot of three separate CDs with pre-emphasis. As of now, they exist for archival purposes as bit perfect rips, stored as FLAC with pre-emphasis intact and tagged in metadata. But for playback, they will require de-emphasis.

What pre-emphasis/de-emphasis solutions do others use? My understanding is that iTunes automatically applies digital de-emphasis, if applicable, in CD playback and ripping. And a digital filter plug in for foobar2000 can be installed to do likewise and more. The latter likely is the solution that I will use, converting the 16 bit FLAC files with pre-emphasis to 24 bit FLAC files via digital de-emphasis.

Probably, pre-emphasis is so rare of an issue as not to warrant Roon’s attention. But as something of a turnkey software player, Roon might want to consider adding a digital de-emphasis filter for CD rips that have been mastered with pre-emphasis and tagged as such in metadata.


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Hi Andrew,

So, ignorant question here, but how did you determine those cd’s had pre-emphasis? Not sure if I have any, or how I would even tell…

if you play a pre-emphasis cd without de-emphasis, it will sound terribly bright, too much high frequency. Here’s a list here of known CDs with pre-emphasis applied.

This is interesting. So if a CD with pre-emphasis is ripped to ALAC via iTunes, then played back in Roon, does the iTunes ripping process apply the de-emphasis, such that it plays back as it should in Roon?

I have not used iTunes significantly in about 10 years, so I can relay only what I have learned from reading reports from others. And my understanding now is that pre-emphasis detection and digital de-emphasis were part of iTunes CD playback/ripping but were removed with a software update at some point.

If true, then ripping with an up to date version of iTunes is no longer a solution for CDs mastered with pre-emphasis. I suppose it is somewhat unsurprising, as even many current CD players reportedly do not recognize pre-emphasis and apply de-emphasis. Pre-emphasis has become a technological footnote. Unfortunately, we still require de-emphasis in order to play back properly all affected CDs.


Is this very obvious? What I mean is very obvious that something is clearly wrong. The point being that I have very many CD’s, in particular from the late 80’s and early 90’s that sound very bright and thin, but I had always thought that this was simply because the mastering was very bright and thin. So is a simply badly mastered CD easily discernible from one that has pre-emphasis?

No, not necessarily. That is why the ear test, in my opinion, is not a reliable one for pre-emphasis.

We really should rely on accurate pre-emphasis detection at the CD ripping and/or file playback stages. I use dBpoweramp as my go to CD ripper, and it detects pre-emphasis, tagging as such in metadata. However, to add another frustrating wrinkle to the pre-emphasis conundrum, dBpoweramp detects pre-emphasis only when it is flagged in the CD table of contents. Some CDs, though, have pre-emphasis flagged in what is known as the subcode. Detecting pre-emphasis flags in subcode is a real burden for CD ripping.


From another thread, here is a post about my search for solutions to the pre-emphasis problem.


I can easily pick it, I got a good ear and system. Pretty unlistenable, way too bright. If you have a cd with it, and not de-emphasised, you’ll know what to listen out for.

Considering “unlistenable, way too bright” comprises about 20% of my CD collection, I’ll go out on a limb that judging by ear is not sufficient :wink:


Sorry to hear you can’t listen to 20% of your CD collection, perhaps a better digital front end or hi-fi will help you? Out of the 4000 albums I got, can’t think of any that are that bad sound quality wise that are unlistenable, then again I try for the best pressings of albums, mostly non-remastered. But can easily tell if not de-emphasised–unless the album was mastered on the dull or dark side–then I look for non-emphasis versions. My ears are good enough.

My statement of 20% was an exaggeration for comedic purposes.
But thank you for both your sympathy and link! :slight_smile:

Not all CDs mastered with pre-emphasis have the proper flags set on the disc itself. When it does, here’s one way I’ve found to do this is using the drutil command line utility on MacOS with the CD in an optical drive. For example, Michael Jackson - Off The Wall Japan Epic/Sony ESCA 5407 shows:

$ drutil toc

Vendor Product Rev 

First session: 1
Last session: 1
First track: 1
Disc type: 0 (CD-DA, or CD-ROM with first track in Mode 1)
Last track: 10
Lead-out: 42:40.32
Session 1, Track 1: 00:02.00 2ch audio, with pre-emphasis, digital copy prohibited
Session 1, Track 2: 06:06.62 2ch audio, with pre-emphasis, digital copy prohibited
Session 1, Track 3: 09:46.62 2ch audio, with pre-emphasis, digital copy prohibited
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That appears to present a readout of the TOC, which is the table of contents. TOC pre-emphasis flags generally are not a problem for proper ripping software (i.e. dBpoweramp, not iTunes). It is the subcode only pre-emphasis flags that can be difficult to detect.

That said, I have had luck recently with CUERipper. I encountered a disc that I suspected was mastered with pre-emphasis, but dBpoweramp did not detect any flags in the TOC. CUERipper, however, caught the flags in the subcode, confirming my suspicion.


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I apologize for getting slightly off topic, but for OSX i’ve been using XLD (which employs Accurip). Is there any big advantages that dBpoweramp would have over XLD? Thanks.

Admittedly, I have not used XLD in 5-7 years, but I recall it to be a rather bare bones interface. And while I do prefer Mac for both personal and professional reasons, I find Mac to be an inferior platform for CD ripping. Thus, I went out and got an inexpensive PC a few years ago almost solely for the purpose of CD ripping. If you care about editing your metadata/images prior to ripping – instead of trying to fix it in post or just letting Roon do its magic to plaster over shoddy metadata – then dBpoweramp is the best option. Also, dBpoweramp on PC but not on Mac can decode HDCD.


In my experience, dbPoweramp takes less time ripping CDs than XLD, sometimes about 1/5th of the time on a MacBook Pro with Samsung USB external optical drive. I haven’t bothered to debug why this is.

Any further input available from Roon staff?

I use a PRE-EMPHASIS tag where applicable. Foobar’s foo_deemph plug-in reads the tag and applies de-emphasis during playback and file conversion. It would be great if Roon can utilize this tag as well.

Further reading at HydrogenAudio.

Yes, with the addition of the DSP engine in Roon 1.3, implementing an automatically or manually toggled IIR de-emphasis filter should be feasible.


I have taken digital de-emphasis into my own hands prior to Roon. But, for reference, I have in my library 35 albums and counting that are mastered with pre-emphasis. These include some notable albums that other Roon users are likely to have. But not all Roon users have the knowledge and wherewithal to apply digital de-emphasis through other means.


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