Mixed Track Formats Again?

[David_Weinberg]

I posted a similar question in 2020 and was advised at the time the my mixed track format was due to different sampling rates of the download. Okay, that makes sense.

In this case, I ripped the new Steve Reich box set using dBpoweramp and got a mixed track format response:

but of course was puzzled as this was a CD rip in AIFF and not a download with different sample rates or other variables.

I dug down a bit deeper and see in the folder view (thank you Roon for the folder view!) and see that on disc 23, the result is both AIFF and MQA!

I then looked at the same tracks using Finder and see that disc 23 (as are all the discs in this box set) are all AIFF:

So how could Roon interpret the AIFF ripped content of disc 23 to be both AIFF and MQA?

Thanks!

David

[Carl]

@David_Weinberg

So how could Roon interpret the AIFF ripped content of disc 23 to be both AIFF and MQA?

AIFF is the wrapper (like WAV, ALAC or FLAC) the lossless content could be native PCM or MQA encoded PCM.

What do you see in Roon Signal Path screen when playing those track? That’s the true measure S this info comes from the data stream itself (not the metadata).

[David_Weinberg]

Hello Carl,

Thanks for replying to a largely curiosity question…

The signal path for disc 23 shows MQA where all other discs are AIFF:

Showing my naiveté here, but if the disc is ripped to an AIFF wrapper, the lossless content could still be MQA??? Also, why would the source show both AIFF and MQA?

David

[Carl]

Hi again,

@David_Weinberg

Showing my naiveté here, but if the disc is ripped to an AIFF wrapper, the lossless content could still be MQA??? Also, why would the source show both AIFF and MQA?

@Carl

AIFF is the wrapper (like WAV, ALAC or FLAC) the lossless content could be native PCM or MQA encoded PCM.

Yes, the important thing is that the wrapper is lossless, so that bit perfect replay of the original PCM data stream is possible. If not then the MQA encoding is destroyed.

Putting it another way think of the AIFF “wrapper” as a box, within that box is the music.
The music within the box is a PCM stream which may or may not be MQA encoded.

MQA encoded PCM streams still conform to the PCM specification and can be played by non-MQA DACs. However, if passed through an MQA decoder the encoded MQA information can be extracted.

Not quite the same, but within the AIFF (or FLAC or ALAC) wrapper the PCM could be DTS (multi-channel) encoded, but in this case it is only playable on a DTS enabled surround processor (otherwise it sounds like white noise).

[David_Weinberg]

Thanks for clarifying @Carl ,

I always understood that a FLAC or AIFF or whatever rip would mean that resulting content would then be in a *.flac or *.aiff format. That is why I was surprised to see MQA and AIFF for that one disc but not the others.

David

[WiWavelength (Andrew J Shepherd)]

@Carl

Not quite the same, but within the AIFF (or FLAC or ALAC) wrapper the PCM could be DTS (multi-channel) encoded, but in this case it is only playable on a DTS enabled surround processor (otherwise it sounds like white noise).

HDCD is a better comparison, since it is PCM compatible with signaling tacitly embedded in the audio data like MQA.

@David_Weinberg

I always understood that a FLAC or AIFF or whatever rip would mean that resulting content would then be in a *.flac or *.aiff format. That is why I was surprised to see MQA and AIFF for that one disc but not the others.

Some CDs and digital downloads/streams are MQA encoded. No way around it, just a mastering choice.

AJ

[SandsOfArrakis (The Spice Must Flow)]

I always explain this as FLAC (or AIFF in this case) being a container. It holds stuff. Open the doors and you can unload it. In this case PCM or MQA.

That’s why back when using Tidal the files with MQA were shown as FLAC… MQA in Roon’s signal path. For equipment that is not MQA capable the file would show up as FLAC, while an MQA capable device would unpack it and play the MQA file that’s actually inside.

I do find it odd that self ripped music turns out to be MQA. My guess would be that the original disc, that you’ve used to rip, is an MQA CD itself. I don’t have MQA CD’s at home. And all my ripped CD’s (in FLAC) all show up as FLAC.

[WiWavelength (Andrew J Shepherd)]

@SandsOfArrakis

I do find it odd that self ripped music turns out to be MQA. My guess would be that the original disc, that you’ve used to rip, is an MQA CD itself.

It definitely is an MQA CD, probably unlabeled as such. See the screenshot above. Even on the standalone digital album on Qobuz, the 16 bit 44.1 kHz version is MQA encoded.

And to be clear to everyone, MQA is not its own format. It is PCM — just MQA “enhanced.” As such, it requires a PCM physical format (e.g. CD) or file format (e.g. FLAC, WAV, etc.).

AJ

[David_Weinberg]

This all makes sense and broadens my understanding about wrappers and contents, so thanks to all for offering the clarifications. I really appreciate it!

So here’s the one curiosity- of the 27 discs contained in this Steve Reich Collected Works box set, why does this one disc (disc 23) have MQA mastering and the rest of the set is PCM (if I have that straight)?

No need for speculation, unless the mastering engineer is monitoring this thread…

[Mr.Flibble (Uncle Arnie fries them alive with his hex vision)]

@David_Weinberg

In this case, I ripped the new Steve Reich box set using dBpoweramp

@Carl @WiWavelength
Curious, dbpoweramp ripping CDs with MQA!
I’m not sure these CDs have MQA tracks on them in the first place. Could be wrong.

Edit: ignore me. I didn’t read the other posts before replying