DSP with MQA and Meridian

Is there a way I can tell Roon to preserve the MQA signal while using the DSP settings for room correction, but not actually decode the MQA in any way?

At the moment, I seem to have the option to decode MQA in the core and the signal path shows that the MQA signal is restored at the end of the process, but the Meridian 818 is showing this as PCM data (suggesting the first MQA unfold is being done by Roon) or I can tell the core not to decode MQA, but then it doesn’t store and recover the MQA stream at all.

Roon is configured to show the 818 as an MQA decoder and renderer, so I might have expected Roon to simply pass the MQA signal straight to the speakers.

[This all seems to be down to the fact that the Meridian 818 insists on doing the a full MQA decode or seemingly none at all, so it would be a cool work-around to have this as an option. Unless Meridian plan to fix this…]

Have you already read the Roon x MQA KB article?

I think you have to choose one of them.

No. Once the folded MQA stream is altered, it is no longer decodable.

Correct. I would lobby Meridian to get this fixed, which is what I have done (on a personal level). We need firmware for all of Meridian’s products (818v3, 808v6, 218, Explorer², Prime?) which fixes rendering of previously decoded MQA (with intact signalling information, as Roon provides, and other rendering devices are capable of using).

Isn’t doing RC with a DSP which isn’t ‘MQA aware’ kind of undoing what makes MQA MQA anyway (over and above the first unfold just giving higher resolution)?

I thought we were waiting for e.g. Meridian to make some kind of MQA aware MRC in the endoints/DSPs for this to work properly? (Ahem, 861v9, cough, cough…)

Hi Joel

Thanks for your prompt response. This is a pity, but you are correct, Meridian (of all companies) should be able to make their systems render partially unfolded MQA. Amazing others can do this, but the original inventors of the technology can’t!


Hi James

It would be good to see MQA MRC in the end points, but I’m not going to hold my breath.

In the meantime, Roon can do room correction in software (which I think is perfectly valid approach alongside MQA) and output this as an MQA stream, just not one that Meridian’s processors have the ability to decode.


No, Roon’s approach works fine according to MQA specs, it’s just that Meridian doesn’t support it.

  1. Roon does the first unfold
  2. Roon RC or other DSP
  3. Roon adds signaling to tell the endpoint how to complete the MQA rendering
  4. The endpoint (DAC) completes it. E.g. Dragonfly. But Meridian doesn’t support it.

In practice I don’t find that it matters. I have an 818, a Dragonfly, a Hugo and other DACs, and I have tried various combinations and can’t hear any difference. E.g. with the Meridian, if I don’t do DSP, I can choose to let the Meridian do the complete MQA processing or let Roon do the first unfold and then the M fails to complete it, don’t hear a difference.
So I do not have MQA support as a criterion when I buy DACs.
More important to me to get a quality DAC.