Best Practice: ID Tags for CDs with Pre-Emphasis and Decoding HDCD

[Z-Lemur]

Hi all, I've looked around the forums but couldn't find answers to a few questions I've come across while ripping my collection:

I have a few CDs with pre-emphasis that I am trying to figure out the best practice for ID tagging them. I see that in the ripper settings dBpoweramp gives the option to add ID tags for tracks marked with pre-emphasis. If de-emphasis is checked and applied while ripping, is the pre-emphasis ID tag necessary? I'm curious if this could lead to an instance where a media player that can read ID tags sees the pre-emphasis tag and applies de-emphasis a second time.

As for HDCDs, I've ripped all of mine to 44.1/16 bit FLAC as I couldn't wrap my head around the proper settings for decoding or if it would be bit perfect after decoding or not (does bit perfect matter at that point?). Is it still possible for me to decode my 16 bit FLAC files, or will I need to re-rip those CDs? Is it even worth re-ripping them?

I appreciate the input and advice.
Z-Lemur

[garym]

re: HDCD, you can use music converter and the HDCD DSP to turn the 44.1/16 files into 44.1/24 files that contain the '20 bit' HDCD files for playback. Whether it is worth it or not, I'd say in most cases no. Lots of HDCD CDs actually don't use Peak Extension, so there is no benefit to treating them like HDCD in playback. foobar2000 has some components that can show you the HDCD features used in tracks (PE etc.).

I like this thread for 'best practices' in HDCD. One takeaway is always rip to bit perfect 16/44.1 first. One can then always do something different related to the HDCD aspect with music converter.

https://forum.dbpoweramp.com/forum/dbpoweramp/cd-ripper/26666-ripping-hdcds-best-practices

[Z-Lemur]

re: HDCD

Thank you garym.

I checked out the thread and it was very informative and helped me get a better understanding of the HDCD decoding process. From what I gather it is best to have a bit perfect 44.1/16 rip and then, if desired, apply the HDCD DSP. One way or the other, the original audio data is stored in the 44.1/16 rip.

For pre-emphasis discs, I'm still working on understanding the different means to decode the audio so that it sounds as it was intended. I originally thought checking the ripper option to de-emphasize and adding ID tags was doubly applying de-emphasis, but from what I've tested so far on a -26dB pink noise track, ripped once with Release 17.7 and once with Release 2025-04-17, I'm getting audio that sounds different with the same checksum for both (this track did not have pre-emphasis). Loading both version rips into Audacity, inverting one, and then mixing them together resulted in audible noise. Funnily enough, running the same test on a pre-emphasized track (one ripped with 17.7 and one with 2025-04-17, also a -26dB pink noise track), the resulting mix was pure silence. This has led me to ask if this could be a fluke and the non-emphasis rip happened to turn out different between the two Releases.

In the next few days I'm going to re-rip the CD with the different pre-emphasis handling settings and see if this was a one-off occurrence or if there may be some kind of additional audio processing going on in the background of the newer release. I still find it strange that the pre-emphasis track turned out the exact same between releases yet the non-emphasized track was different.

Both tracks came from the same CD: "The Digital Domain: A Demonstration."

I'd appreciate any input that may help clarify,
Z-Lemur

[garym]

You are already above my knowledge level on this re: pre-emphasis issue. I hope Spoon can chime in. All I've ever done is tick the setting in ripper to "apply demphasis to tracks marked with pre-emphasis" and ticked the option to add a "premphasis" field to my metadata tags if this is indicated. My understanding is that doing both of these things does NOT cause any double applying of de-emphasis. The tag is just information that the tracks had preemphasis, and is NOT applying anything. That is the first setting I mention above.

[Spoon]

You would have to test more, you can compare two tracks quickly by select both >> Convert To >> [Calculate Audio CRC]

[Z-Lemur]

Hi All,

I re-ripped the CD that was giving me issues, and it appears that the CD Ripper is applying de-emphasis to tracks not marked with pre-emphasis. Most tracks on the album have pre-emphasis, but quite a few at the end do not. The only setting I have set in the ripper settings is "apply de-emphasis to CD tracks marked with pre-emphasis."

Spoon, I took your advice and compared the CRC value for this rip (Release 2025-07-21) to the one I made on Release 17.7 with this result:


CRC32 ; MD5 ; AccurateRip CRC ; Filename

D4D8355C ; DEEAE44D0761BEF8CCE2A0E7359650EA ; 8D411B1F ;
C:\Users\XXXXX\Music\z Test AccurateRip Folder\Pre-Emphasis Tests\Test 4 - The New Rip - No Emphasis\2025-07-21 - 23 Pink Noise @ -26dB No Emphasis.flac

3CC5B8A2 ; 33984F3FD0DFBBF2A0E3917C4D66E135 ; D5393594 ;
C:\Users\XXXXX\Music\z Test AccurateRip Folder\Pre-Emphasis Tests\Test 4 - The New Rip - No Emphasis\17.7 - 23 Pink Noise @ -26dB No Emphasis.flac


Below I have images of more of my findings. I apologize if attaching images aren't permitted. I am still relatively new here.

Initial Rip Result:

This shows that de-emphasis was applied for the rip.

Main CD Ripper Screen:
Track 23 should not be having de-emphasis applied, as it is not marked as having pre-emphasis, which the ripper correctly identifies here. I included Track 22 for reference.

Tags Window:


Is there a setting I am missing in the ripper options, or could this be a bug?

Z-Lemur

[Spoon]

Ok will look when next in CD Ripper, thanks for the thorough testing.