MQA files turning DSP off?

Roon is clearly able to detect a file to be MQA when it is playing (the signal path indicator shows this).

It would be useful if in the case of a non-MQA file, Roon enabled upsampling while automatically disabling it when playing an MQA file. It would be a user choice of course.


I do get that detection happens once the file starts streaming and as such you don’t want to be switching DSP on/off midstream. I understand you might want to delay this feature until proper reliable metadata indicates a file is MQA-encoded.

Roon won’t really play well with MQA until this is implemented.

It seems to me that there could be a kind of manual workaround where the user selects albums known to be MQA and marks them as such so that Roon can disable DSP when a track from that album plays.

A second issue is the volume/gain level. Maybe this is specific to the Pro-Ject S2 Digital and their filter issues in firmware, but I have generally noticed that MQA files sound louder. So even with DSP dynamically turning on and off with MQA files, there may need to be some sort of volume leveling done – likely on the non-MQA files only – to even out the listening experience.

(As an aside, this is the type of inconvenience one ends up with when dealing with an end-to-end solution like MQA. It creates a silo that doesn’t play well with others.)

I believe MQA does potentially allow for DSP? If so an implementation that did the first decode and allowed dsp could be interesting.
Give me a minute to find my tin hat… :confounded:

That would be great - then we could level volume among other benefits. I am skeptical though – that would not trigger the blue light on MQA DACs. Hard to believe that MQA Ltd. would allow that, but that discussion has been going on in other threads for years…


As always time will tell.

Yes it will!

Audirvana does exactly this: It does the first unfold and then upsamples (ie if you chose to). Obviously this is not full unfold - the merits of which I do not intend to discuss.


Thanks for the update.


Any DSP post first unfold will effectively destroy the MQA rendering information, so “no blue light for you!”

There are no MQA implementations - not even Meridian’s to my knowledge - that allows DSP above and beyond the rendering stage.

MQA process is:
1- First unfold; and
2- Upsampling (aka “rendering”, ie upsampling with specific filters).

Presumably after the second step you could apply DSP such as room correction - but I am not aware of any solution that does this, not even Meridian’s systems.

Once the first unfold is done (in Roon or Audirvana), one could conceivably choose MQA-like upsampling filters to “render” to the target sampling rate, then apply whatever DSP you like.

PS: If/when Roon does first unfold that is…

Tidal’s own client allows you to:

  1. Passthrough content unchanged (i.e., for use by an MQA-enabled DAC)
  2. Perform the first unfold in software

Would be great to have that flexibility in Roon when / if MQA software unfold Is implemented.

To be very precise, to date: On mac, there are two ways to do the first unfold:TIDAL native app, and Audirvana. On Windows, only TIDAL native app (to my knowledge). Audirvana can also be set to pass-through.

CORRECTION: Looks like an app called XXHighEnd can also do first unfold on Windows.

The TIDAL native app does not allow for upsampling though. So to date the only game in town for upsampling a first-unfolded MQA stream is via Audirvana.

Rumor is Roon will be adding first unfold soon, which in principle would allow you to upsample a first-unfolded MQA stream should you wish to.

It is entirely possible that MQA has put a restriction on the Roon first-unfold license to prevent upsampling with Roon’s algos. In which case first unfold followed by upsampling is only an Audirvana trick, or a Roon+HQPlayer trick.

This is a bit confusing but there’s no greater simplification I can think of.

Do we know for sure that if you are upsampling an MQA file in A+ that you are upsampling the first unfold?

And you’re not just upsampling the unfolded MQA file like Roon already does right now?

Good question - no we don’t know that for sure, but it would be weird for it to be otherwise. Audirvana identifies the file as MQA, it is set to do first unfold, and the output rate is higher (eg 384), so I assumed that it was unfolding then upsampling. I will ask Damien (the developer).

Ya but so does Roon right now. Roon will still tell you it’s upsampling an MQA file with upsampling enabled - except obviously right now no first unfold in Roon. Not sure we should assume/guess A+ is different.


Nope. Roon never tells you it is unfolding the file. It just tells you what the data is. Yes one could assume the same of Audirvana.

Check above, i replaced unfolding with upsampling - as you replied.

I haven’t seen any info to assume/guess that A+ is different to Roon right now, with upsampling MQA files.

Both will tell you that it’s an MQA file that is being upsampled but there’s no ‘additional’ info in A+ to tell you it is upsampling the first unfold (if you are doing upsampling).

Damien will put an end to our guessing of course.

Hmmm… You raise a good point here… If I recall correctly, you can choose between:
1- No MQA Device – First unfold and (I expect) upsample
2- MQA Renderer – First unfold, no upsample
3- MQA Passthrough – Signal untouched
(exact wording escapes me now)
Choosing 2 or 3 surely must avoid any upsampling or else it would not be able to render or decode respectively.

Absolutely, agreed with #2 and #3.

But your earlier statement “Audirvana does exactly this: It does the first unfold and then upsamples (ie if you chose to)” relates to #1.

But we go in circles with guessing. Hopefully Damien can put us out of our misery :slight_smile: