Anyone heard about Meridian's new project called MQA

[HansBeekhuyzen]

What I didn't realise about MQA, until I read the Harley review, was that MQA was more than just a clever way of delivering high quality audio at lower bandwidth - it also addressed some aspects of digital filters. I guess that I should have realised this from Stuart's AES paper but I didn't.

There are actually three properties to MQA: controlling time smearing, guaranteeing file integrity and reducing bandwidth (as I mentioned in my video)

 

[HansBeekhuyzen]

Thanks, Orb.

I'm curious. Have you ever auditioned or heard any of Bruno's designs?

C'mon now, do you homework. Grimm Audio speakers are on every international show and they are extremely good. The best of the best studios work with Grimm Audio ADC's. I have worked with two of Grimm Audio's engineers (Peter van Willenswaard and Eelco Grimm) for years when they worked at ProAudio Magazine in The Netherlands. And I know the work of Guido Tent as well. I vouch for them 100%, including Bruno. I'm not a fan of UcD (or any Class D amp for that matter) but that product was developed for low budget applications, top engineers - even the likes of Bruno - also need to develop budget equipment and it's unfair to judge him solely on that product.

 

[HansBeekhuyzen]

Now, I think your question about whether this characterization is limited to just a single ADC or the entire chain is a valid question. I'd like to know that as well. In the analogy I used, the correction models the entire optical path, even if it involves multiple lens elements, so I wonder if it's possible to model an entire recording chain.

That depends on the audio set used. If Tidal offers MQA decoding in they playback software, it will not include the DAC. But in Meridian's top set it might even involve the impulse response of the speakers since DA conversion is done in the speakers.

 

[amirm]

Well, they did it before with MLP that is used in Dolby HD......

That was done with Dolby's political power, not Merdian on its own. After developing its own codec (Dolby AC-3/surround), Dolby went through a period of realizing no one would license proprietary codecs anymore and decided to get in the business of licensing other technologies and that is how MLP came about (renamed to Dolby TrueHD). Hollywood which was critical in getting adoption of Dolby technologies in optical media to this day has no idea who Meridian is. They know Dolby however.

 

[JonFo]

That depends on the audio set used. If Tidal offers MQA decoding in they playback software, it will not include the DAC. But in Meridian's top set it might even involve the impulse response of the speakers since DA conversion is done in the speakers.

Thanks for the reply Hans, but I was asking about the input side. In other words, is the 'correction' characterization injected into the MQA file representative of just a single A/D device, or a more comprehensive model?

I get that on playback the ideal MQA setup does the characterization de-convolution as far down the chain as possible (e.g. Meridian SE speakers).

But that brings up yet another question: If I can characterize the impulse response of my DAC, can I feed that to an MQA decoder so it can consider that in the overall correction?

 

[Orb]

C'mon now, do you homework. Grimm Audio speakers are on every international show and they are extremely good. The best of the best studios work with Grimm Audio ADC's. I have worked with two of Grimm Audio's engineers (Peter van Willenswaard and Eelco Grimm) for years when they worked at ProAudio Magazine in The Netherlands. And I know the work of Guido Tent as well. I vouch for them 100%, including Bruno. I'm not a fan of UcD (or any Class D amp for that matter) but that product was developed for low budget applications, top engineers - even the likes of Bruno - also need to develop budget equipment and it's unfair to judge him solely on that product.

Yeah I cannot remember which primary member/contributor at Grimm Audio decided to set-up a more thorough test involving jitter by actually modifying the actual DAC-clock circuitry to create real world 'seen' jitter errors, rather than say relying upon J-Test that stimulates jitter.
Was an interesting bit of work he did as it is like injecting errors as done with BERT albeit very specific to jitter and jitter type/pattern at the right point in the DAC, that no-one else has bothered to do.
Cheers
Orb

 

[jkeny]

There are actually three properties to MQA: controlling time smearing, guaranteeing file integrity and reducing bandwidth (as I mentioned in my video)

Right but the property I'm mostly interested in is the reduction in time smearing

 

[jkeny]

Yeah I cannot remember which primary member/contributor at Grimm Audio decided to set-up a more thorough test involving jitter by actually modifying the actual DAC-clock circuitry to create real world 'seen' jitter errors, rather than say relying upon J-Test that stimulates jitter.
Was an interesting bit of work he did as it is like injecting errors as done with BERT albeit very specific to jitter and jitter type/pattern at the right point in the DAC, that no-one else has bothered to do.
Cheers
Orb

Do you have a link for that test & results

 

[Orb]

Do you have a link for that test & results

Unfortunately Jkeny no,
it was not done as a paper release but for his own interest-understanding on implications in real-world systems; although we are talking about one of the top digital-audio electrical engineers so I trust the work and his experience from it.
This is going back a few years now, hence why I am not sure which engineer it was associated with Grimm Audio and do not want to name the wrong guy, but we are talking Guido Tent level.
Cheers
Orb

 

[jkeny]

Unfortunately Jkeny no,
it was not done as a paper release but for his own interest-understanding on implications in real-world systems; although we are talking about one of the top digital-audio electrical engineers so I trust the work and his experience from it.
This is going back a few years now, hence why I am not sure which engineer it was associated with Grimm Audio and do not want to name the wrong guy, but we are talking Guido Tent level.
Cheers
Orb

Thanks, Orb

 

[HansBeekhuyzen]

I get that on playback the ideal MQA setup does the characterization de-convolution as far down the chain as possible (e.g. Meridian SE speakers).

But that brings up yet another question: If I can characterize the impulse response of my DAC, can I feed that to an MQA decoder so it can consider that in the overall correction?

About how the characterization of the AD side Meridian is quite secretive. As far as I could find out or work out they have means to analyze program material. This is a part of the MQA encoder and, amongst other undisclosed techniques analyzes the noise floor!?!.

I don't think that Meridian wil allow you to characterize your own DAC and make that fingerprint part of your decoder, apart from the fact that this would need two DPS processes which wouldn't be ideal IMHO.

 

[HansBeekhuyzen]

Right but the property I'm mostly interested in is the reduction in time smearing

So am I, although the idea of authentication 'sounds' good too

 

[HansBeekhuyzen]

Yeah I cannot remember which primary member/contributor at Grimm Audio decided to set-up a more thorough test involving jitter by actually modifying the actual DAC-clock circuitry to create real world 'seen' jitter errors, rather than say relying upon J-Test that stimulates jitter.
Was an interesting bit of work he did as it is like injecting errors as done with BERT albeit very specific to jitter and jitter type/pattern at the right point in the DAC, that no-one else has bothered to do.
Cheers
Orb

I don't know but the nice thing of the team is that they are highly complementary. Already in the mid eighties Peter and I discovered jitter (although we did not know it was jitter) and were bashed for it. Ones are ones and zeros are zeros and transport of ones and zeros is easy. So what were we talking about. It's a bit like now is talked of time smearing.
Some people trust their measurement equipment more than their ears and then claim integrity......