MQA at CES

[firedog]

To me, interesting interview:

 

Meridian

 

Meridian Co-Founder and MQA Co-Architect J. Robert Stuart Talks with Robert Harley

 

more info-press releases:

 

MQA Explained in Short Videos | The Absolute Sound

MQA Launches Content at CES and Teams with HTC for World's First Smartphone MQA Demonstration | The Absolute Sound

[firedog]

To work correctly and not cause problems the exact identity and filtering of the DAC must be known. While this could be chosen in software if known, from what I can tell, at least initially, Robert Stewart does not intend to allow this because he wants to eliminate the possibility of someone choosing incorrectly and getting compromised sound.

 

Apparently there is going to be a "general DAC profile" in software for systems where the DAC isn't known. I read this yesterday, in some of the CES coverage, don't remember where.

[firedog]

Fair enough. Let me clarify. MQA might very well be the de facto standard for hi res streaming but ofcourse there is competition. If you don't think DSD will respond to the threat from MQA then think again. MQA aka Meridian aka Roon spinoff are trying to corner the hi res market just like Apple did for low res music. It's always about money!

 

A little paranoid? ... How is anyone - especially a tiny company like Roon - trying to corner the market? And "DSD" is a format - it can't respond to the non-existent threat. Are you trying to say some proponent of DSD is going to come out with a competing DSD package to compete with MQA for streaming? I seriously doubt it - those little companies are doing all they can just to keep DSD a living format.

 

Neither Roon nor Meridian have any reason to be against DSD and I haven't seen any evidence they are - especially Roon. One of Roon's first "upgrades" in functionality was to integrate HQPlayer - the DSD'ers favorite toy.

[firedog]

It's always about the money. Who do you think stands to benefit. DSD is a format just like MQA wants to be a format. License fees. Meridian. Roon. Streaming services. They just want users to pay a monthly subscription. Are you kidding. Meridian wants MQA to be the de facto standard since they think they have a better format except the just fucked over one of their biggest early supporters Auralic.

 

Fees? Tidal has said they will provide MQA at no extra cost to users who in any case have a subscription for lossless streaming. As I'm not required to buy into MQA on the HW side to continue streaming - it costs me nothing unless I decide I want an MQA HW device. And BTW, they didn't f**k over Auralic, it apparently was a misunderstanding and a solution has already been worked out that needs to be implemented.

 

I haven't seen anything so far that tells me I have to spend any money because of MQA. I can continue listening with the pre MQA formats and MQA costs me nothing. Even when it is implemented in Tidal it won't cost me anything beyond what I'm paying now.

[firedog]

You grossly misunderstand. Digital is not like making sausage. Masters (in whatever form) are only the best archive source and always remain unaltered; MQA is a derivative file, like all other digital attempts to optimize.

 

Until the "master" is an MQA file. Don't think it can't or won't happen. Record companies don't actually behave like you are assuming and make a big effort to keep some pristine "master" version around. Sometimes they do, sometimes they don't.

 

No different than basterdized versions (say with heavy volume compression) becoming the "master"- and after this happens no other version seems to exist anymore. Yes it does happen.

[firedog]

After reading computer audiophile newest article detail about MQA it confirms my already suspicions about MERIDIAN vs AURALIC who embarrassed AURALIC and the truth will come out sooner then you think. STILL NOBODY can answer the question what an MQA approved DAC or streamer really is!!!??

Please advise.

 

Computer Audiophile - CES 2016 Wrap-up

 

Really? You're the secret CEO/spokesman for Auralic with knowledge and authority to tell us they were embarassed...? Not!

[firedog]

That sounds really backwards to me (i.e., seems like you'd want to "correct" *after* the DAC has done its magic but before sending to the speakers) but thanks for clearing that up. Obviously, I don't use room correction.

 

It's not backwards because it's digital room correction. I'm not saying that to be condescending. Basically DRC (as opposed to EQ) became a real possibility for home audio use once computing became relatively inexpensive (something like 20 years ago, I don't remember the details).

Almost all DRC programs for audiophiles work on 24/96 streams (some setups convert any incoming digital to 24/96). It's pretty much predicated on the ability to apply the DSP derived from the room measurements to the digital stream on the way to the DAC. Applying the RC in the analog domain would be A LOT tougher to do accurately and well.

[firedog]

While the MQA decoder can incorporate software-based DSP for room correction or EQ (e.g. in AV Receivers), any such processing (including sample-rate conversion or software-based upsampling), can’t be introduced between the decoder and the DAC chip without breaking the chain.

 

I read this to mean that DSP software producers could work out a deal to incorporate their software into MQA, at least theoretically.

[firedog]

"According to MQA’s Bob Stuart, the brickwall filters in a studio’s A-to-D converter smear the time domain accuracy of the incoming analogue signal as it is encoded to digital."

 

Why on earth would I trust that meridian are able to improve on ADC from long time specialists like grimm and others that make ADC that are considered excellent? Why should we focus the improvement there? And if we should, how exactly does it work the meridian mechanism to correct those innacuracies.

 

One of the concepts behind MQA is that every ADC (and DAC chip) has specific inaccuracies that you can profile. Hence you can set up a software mechanism in MQA that corrects for these specific innacuracies. So MQA isn't improving on the ADC per se, but it is correcting the resulting innaccuracies.

 

I don't think there is really any argument that the idea behind this is correct. (That all DACs and ADCs have charactaristic "faults" that can be corrected). It remains to be seen if the specific MQA solution really leads to improved sound.

[firedog]

Further explanation:

 

No filter, whether in an ADC or DAC, is perfect. It cannot be, even by design, because of the way the mathematics behind filters works: As the filter is adjusted so "time domain" distortion (ringing, which is said to "smear" transients) is minimized, "frequency domain" distortion (aliasing, which causes harmonic and intermodulation distortion) gets worse, and vice versa. One can try to minimize ringing that occurs prior to transients for a more natural sound, but the means of doing this (often a "minimum phase" or "intermediate phase" filter) lead potentially to other problems, such as "dispersion" (where how fast the signal gets through the filter depends on frequency).

 

So in reality, you can't simply counteract all the imperfections in every ADC filter, since your result would inevitably also have imperfections, just in a different balance than the original. What you can do is take filters that in your estimation err too far toward one side of the balance, and change that balance for what you think is the better. In general, what Meridian would do is to take ADC filters that in their (and others' - they're not alone in their thinking) opinion ring too much, and counteract that with "apodizing" filters to remove most of the ringing. "Apodizing" filters start cutting the signal in the uppermost part of the audible range, allowing a gentler filter slope while still doing a good job stopping aliasing. The gentler filter slope helps eliminate ringing. Meridian's filters (all apodizing filters?) also utilize "windowing" functions to cut down on the ringing. I don't know enough about windowing functions to hazard an explanation.

 

So that, in general, is what MQA sets out to do, encoded in a technology that also purports to offer hi res recordings at lower res bandwidth if you have the MQA-licensed decoder.

 

I don't claim to know exactly what they are doing, but I don't think your explanation quite covers it. They claim they are going to have individual "correction" for each ADC and DAC that asks to be "certified", so I think there is a bit more to it than what you seem to think.