MQA and Room Correction

Is there a way to apply room correction to MQA audio streams ?
Is there anything known that might work in the (near) future?

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As soon as Roon can decode MQA you’ll be able to unfold once and then apply your room correction.

Room correction is destructive to PCM data there is no way to preserve MQA data for a downstream DAC.

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Well, thats good news.
Always having behind in my head the differences in different unfold levels.
Which has to be experienced I think.

Oh, Dirac eliminates itself from that list by its setup possibilities.
It works only as an “asio” driver.

It’s worthwhile bearing in the mind the Diagram below, which comes from the in depth Q&A regarding MQA on CA…

As posted elsewhere

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Dirac sets itself as a virtual soundcard. You then choose it as a zone inside Roon. I can’t se why Dirac shouln’t use the once unfolded MQA signal from Roon when Roon becomes able to unfold.

@TreeZorro That will work with the partially unfolded MQA (unfolded by Roon to 88.2k/96k), but there is not currently, to my knowledge, any hardware or software MQA solution, which combines room correction and the full MQA decode.

Before seeing your post I guessed Roon would be the first solution to do what was said by Bob Stuart in Q&A article A65:

The main decoder produces an intermediate signal and processing, such as multichannel up-mixing, room correction or crossover, etc. may be performed on this. A software decoder may include a side-chain API where such processing can be inserted, as it is already in mobile implementations.

Here MQA needs to offer a solution for the market.
Because I will not buy MQA titles without a real setup for room correction.

I tried that with Audirvana 3 and it didnt work for me. I will invest more time on the weekend.

I did this last night on A+ 3 without issue. Tidal MQA first unfolding by A+ 3 and then fed into Dirac. There is no reason why any software decoder like Room or A+ can’t apply DSP after the first stage software decoding/unfolding.

It’s still seems unclear if one will be able to apply the DSP at this point and then still get second stage unfolding via an MQA Dac. Has anyone tried testing am MQA Dac in the chain after A3+??

You are correct that if full MQA blocks DSP that will be a tough sell. The gains from DSP will easily outweigh the gains from a second unfold. I would think that they have thought about this …

An aside, but Audirvana 3 sounds very good …

thats the trouble

From what I am gathering, if you set A+ 3 to send MQA data in “rendering” mode, in which A+ does the first stage software decode, it also blocks any audio processing before sending the signal on - intentionally or not. So there is no way to currently test whether or not applying some simple DSP like PEQ might break the second stage DAC “render”. Maybe when Roon adds MQA decoding it will be put through the ringer …

Yes that’s what I meant. Just the first fold. I can see I wasn’t totally clear in my statement… It may need deblurring:slight_smile:

I sense Bob Stuart wasn’t of the same opinion in the CA Q&A:

Room Correction - Question 65(g)

g. In comparison a lesser compressed master files with real 24 Bit 96 kHz sample rate from start to finish (in a real lossless codec) will do a more practical job, in our daily homes, especially when you plan or already use a Digital Room Correction (in the digital path, between or in the playback software, and before the DAC).


g. We respectfully disagree. Such a system might appear to be convenient but will always deliver lower quality and be lower resolution and further away from the studio original.

Fair enough, but in the rest of Q65 and as per above, he clearly states and outlines that room correction is possible and provides a diagram showing where DSP would occur - in between the decode and render stages. In his answer to 65g, I am thinking that he was more focussed on the “less compressed master files with real 24 Bit 96 kHZ sample rate …” part of the question than the follow-on regarding DRC.

Yes, you could be right but I’m pretty sure I saw another comment in a different article basically underplaying the importance of DRC relative to MQA.

The thing is I don’t think anyone knows how that diagram can be achieved in the real world - for all we know it may require the player, DAC, and DRC to all be in the same physical unit, or the DSP code may have to be specially written around MQA. It’s all a bit unknown and I don’t believe anyone has a working system mapped out for this scenario.

DRC was certainly way more beneficial than MQA to my ears and in my setups. (Only tried hardware decode on an explorer 2 and lower-end headphones that being said). I wouldn’t jump through hoops to accommodate MQA from what I’ve heard so far, but I would put in DRC effort.

I’ll be interested to see if and when the first full decode with DRC becomes available.

I also want room correction more than MQA.
For speakers.
For headphones, which I use a lot, the corrections and upsampling are unimportant, so MQA wins. Just slightly.

I guess if you have a perfect room/studio then MQA would be more important, but at least for me the improvement I got from room correction with REW is far more than any improvement MQA or higher sample rate would mean.

But a good compromise would be if Roon did the first unfold, then if you apply any DSP (like room correction), the MQA info is removed and sent to output as it is. Its not like going from 88/96 to 176/192 will give any big improvements (in fact, I am willing to bet that unless you have very high end gear in a studio, and very good listening ears, you would fail a blind test).

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What does the first unfold do in MQA?
What does the second unfold do?

If the unfold relates only to the bits/kHz, then I see no problem applying Room Correction after the first software driven unfold process.
But in case other “MQA related necessities” are involved in that second hardware driven unfold, any decision becomes more “interesting”.