Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion MQA - Related technology, products and music Multichannel MQA

Yes. I play files almost exclusively and the majority are HD multichannel up to 24/352 PCM and DSD256 via exaSound e28 or NADAC into an Audio Research MP1. Disc playback could be improved, though.

Until the release of Bob Stuart's Q&A session on MQA published in Computer Audiophile on 4/7/2016, it was certainly not clear to me how they were correcting for the impact of both the "gateway" a/d and d/a digital filter errors in the MQA digital ecosystem. In the article, (required reading) it is now clear that the new process is NOT based on apodizing filters, but rather on detailed bit-by-bit cancellation tables for the digital filter induced ringing response on both ends of the digital audio datastream.

These tables must alter the digital data in such a way that the errors in the reconstruction filter exactly complement the alterations in the digital datastream itself such that there is NO ringing in the analog output either before OR AFTER a high frequency signal impulse. (In amplifier design parlance, this is in essence, a feed-forward approach, whereas an apodizing filter is, in effect, a negative feedback approach). This is indeed different than conventional LPCM, DXD, or DSD processing. This also explains why simple firmware updates for your existing DAC's may not be sufficient, because the computing horsepower required to do this, in real-time playback, is quite intensive.

Bob also states that a MQA topology for MCH surround processing has been under development, but that it requires two decodes - one before the DSP processing for room correction, etc, and one afterward, just prior to the D/A gateway back to analog. The second decoder presumably updates the complementary correction tables for changes the surround DSP's make in the digital data stream. This also makes sense to me, because if, for instance one chooses to use Trifield, a unique "rendering" file must be created for 3-6 data streams, vs. the two MQA encoded data streams that come into the box from the source.

In any case, It appears a MCH MQA solution is in the plan, however, Stuart and Meridian are not quite ready to talk about it yet. I, for one, will save my nickels for when the 861v9 or G65.1 are announced, but I see no need to spend more than $299 for an Exploerer 2 until then. The ironic thing is, even with an Explorer 2 DAC, my G68 will screw up the decoded signal as soon as it goes into any analog input, because the G68 has no analog pass-thru. The irony is that Stuart may very well end up selling a lot of Meridian owners on someone else's brand analog preamp - make mine a Pass XP-10.

My fear is, when it's all said and done, the investment hurdle and lack of upgrade capability may resign a lot of audiophiles to 2-channel analog listening on their high-end systems (ala MQA-mastered vinyl), and MQA on their computers... not exactly what everyone was expecting at the start of this.

That gets to my original point - Meridian became highly successful by bringing high definition multichannel digital sound into being. If they can't, quickly, work up a transition plan for this market space, (i.e. MCH MQA), then it will either die, or be (unconsciously) adopted by primarily today's MP3 consumer, with little new business for Meridian itself.

Technology innovation and working business models are not intrinsically linked.

Don is referring to this article with Bob Stuart.

In all honesty,
MQA is a mess for a normal consumer... I see myself as a advanced consumer and have a good understanding about MQA and understand the advantage. So the technology is fine... But the marketing strategy from Meridian is huge mess. There is no clear roadmap for their products and no information for current owners about how to obtain MQA. In the meantime other brands are implementing MQA into their products... almost feels like the inventor of MQA is lagging behind?

I would expect a high end provider like Meridian to have a roadmap for their products before they start developing new audio formats! At least they should have presented the roadmap very early in the process. There is so much confusion going on... A lot of Meridian owners have done huge investments into products that has been promised to be future proof and we don't even get a roadmap! The only thing we got is a huge amount of speculations and rumors. It's good that Meridian develop new formats as digital pioneers, but they somehow seem to forget their current customers on the road somewhere.

Come on Meridian you must be able to do better than this!

I don't think there are any certified MQA players apart from Meridian, currently? The Mytek Brooklyn is not yet released, only announced, I think. (Happy to be corrected.)

I don't want to defend Meridian's culture of secrecy, but I am sure there is a roadmap, and possibly a bunch of products waiting for release. They have their hands tied, I suspect, until there is an MQA release beyond the 2L one. We need Tidal and at least one major. I'm sure it's not far away.

By the way, MQA is in the hands of MQA Ltd. which is a separate company, although with close ties to Meridian. But no-one works for both, to my knowledge.

You got the Pioneer XDP-100R for instance and you can connect the Meridian Explorer2 to any analogue high end system and get MQA all the way.

I understand that they are two separate companies, but the marketing strategy has not been that way. At least not for Meridian owners. If they did MQA Inc on the sideline without mixing into Meridian products it would be different. Problem is that they have been using MQA to hype Meridian products for 2 years or so. They must know for sure that they got a lot of customers waiting for answers.

It's just like the Sony Alpha 7 system, they had a new high end camera system but no lenses for it. (other than kit lens) but due to the roadmap they provided for the next 3 years it was easy to jump on that horse because you knew what to expect.

How hard can it be to present what to expect for Legacy owners?

And at least they should come up with a roadmap for their 861 owners... Do we need a new plug in card, or do we actually need to replace the whole unit? Will multi channel ever be supported? and so on... Questions are many.

Meridian is never specific beforehand on HOW they will solve something but these things is the WHAT for the 861 owners:

1. Best in class Immersive Audio Capability, that technically means more channels AND good non-time-smearing algorithms that handles positional and virtual speaker layouts to get the most benefits and flexibility from Immersive Audio.

2. MRC updated with less detrimental and better precision algorithms with what has been learned from MQA research.

3. Multichannel ID4x audio endpoint to finally give the 861 the multichannel music capability it lost when the 800 series DVDA went to the grave in the new guise of Sooloos/Roon streaming multichannel audio. DXD/DSD 5.1 native or converted to MCH MQA.

4. Mconfig migrated to a realtime App able to control all Immersive audio capabilities and configuration over ID4x ethernet card. Modernise the Configurate/Save/Store process and make everything realtime with Apply/Save/Undo.

5. A modern INFORMATIVE HD Front panel for the year 2017? Or do we aim to directly go to the Virtual Reality Minority Report display/configuration in 2020?

I must admit I read this answer (A65) as referring specifically to the surround processing (including room correction) of a two-channel MQA input rather than a MCH MQA input.

As they are two separate companies they cannot use or review the MQA research data for use in their products. Meridian should not have any benefits from MQA that will not also be available for other vendors like for ex. Pioneer.

There's no problem here, as I see it. MQA will/should have to accommodate side processes (e.g., EQ, bass management) on any device where the particular manufacturer deems it necessary and the 2-decoder configuration permits that. How each does it likely will be different.

It would be a two step process I would assume...
MQA processing both before and after changes are made.
Question is however... how much DSP processing can be allowed and still be qualified as MQA?

If you add EQ for your own taste then it's not like the sound engineer designed the production anymore. Or even more, is it really possible to say that Trifield ever can be MQA? You can probably get the resolution but it would not be MQA?

In my mind only Discrete and Direct modes could be true MQA end to end.

I appreciate the issue but what about bass management? Clearly, it is just the redistribution of original content to additional output channels? And processes for Trifield or REQ should be considered superimpositions, not corruptions, if handled right.

I am not a stickler for getting the MQA light on as evidenced by my preference for listening to almost all my DSD sources converted to PCM in order to permit REQ. Same here.