Your Chance To Ask Bob Stuart Anything About MQA

[james45974]

My understanding is MQA is supposed to be "end to end", therefore:

 

1. Will there be separate analog and digital masters? In other words, with many analog (vinyl) recordings starting off as digital masters what will be the extent of MQA in the analog signal chain?

 

2. Again, with the intent that MQA will be present in the very beginning of the signal chain, are the psyhcoacoustic issues being talked about for digital in the analog domain also? Why or why not?

 

3. Is MQA compliant with redbook and will there be MQA CD's produced?

[Paul R]

Will there be a consumer version of MQA to convert existing hirez file (like 192/24) that I have created to MQA files. I am thinking about being able to have greater portability of my files.

 

+1.

 

I am unclear how MQA can improve Redbook, HiRes PCM, or DSD files actually, but if it can, having a way to convert existing files would be very nice indeed.

 

-Paul

[miguelito]

So what's the deal Chris? When is this happening? Can't wait!

[The Computer Audiophile]

So what's the deal Chris? When is this happening? Can't wait!

I'm going to use my best judgment then give a 24 hour notice of closure of the thread. I'm guessing this week some time.

[miguelito]

DRM DRM DRM - what technical and/or legal assurances does a user/purchaser of MQA (which is an IP/patented protected technology) have that MQA will not now or in the future serve as part of a DRM system? Not interested in personal assurances, good intentions, or a simple "we have no plans for that". What LEGAL rights do the purchaser of this technology have that protects them from MQA based DRM (if any)? Since the answer is probably "none", what changes to the licensing is Meridian prepared to make to assure the audio community that MQA can never be used as a DRM mechanism?

To add to this:

 

If MQA incorporates DRM at such level that the file cannot be played at all (MQA decoding or not) without authentication... What format would this file be in? That is: it could not be FLAC, could it?

[mmerrill99]

I've seen mentioned two technical aspects that MQA focusses on:

- Temporal de-blurring

- zero noise modulation

 

Both of these have been stated to be routed in psychoacoustics. I've seen the figure of 4uS or 10uS inter-aural threshold stated in the neuroscience literature but haven't seen any thresholds for noise modulation?

 

So a number of questions:

- let's say there's an improvement of 100% when using MQA - what percentage of this improvement would you say is accounted for by temporal & what percentage to noise-mod improvements?

- what papers or studies in neuroscience have studied noise modulation & it's audible effects?

- do you see the biggest contributor to noise modulation being the result of the feedback mechanism & noise shaping of sigma-delta modulators and/or some other mechanisms?

- Are you are addressing temporal de-blurring by using digital filters which address this (such as apodising filters)?

- how are you addressing the noise-mod problem?

[The Computer Audiophile]

OK Guys - 24 hours from now I will close the thread to any more questions.

 

This is your chance to clear up any confusion you may have with respect to MQA.

[The Computer Audiophile]

Based on the music released by 2L, it appears that the MQA version of this music is roughly two times larger (in MB) than the CD 16/44.1 non-MQA version. This makes sense to me if the original source is high resolution such as DXD or 192 kHz. However, when the original source is 16/44.1 I don't understand how or why the MQA version is larger than the original.

 

 

Example:

 

 

Carl Nielsen: Chaconne op 32 (Christian Eggen) was recorded to DAT at 16/44.1. The CD version is 33 MB and the MQA version is 80 MB.

 

 

2L High Resolution Music .:. free TEST BENCH

 

 

 

 

Question: Can you explain why the MQA version of 16/44.1 CD material is larger than the original 16/44.1 CD material?

[The Computer Audiophile]

After purchasing an MQA album in a format such as FLAC, will consumers be able to convert the files, using software they already own such as JRiver, XLD, or dBpoweramp, to another format such as WAV or AIFF or ALAC without destroying MQA features of the file?

 

 

Put another way, if I convert an MQA FLAC file to AIFF, using JRiver Media Center, will the MQA light still illuminate on my DAC when playing the AIFF files?

[JR_Audio]

After purchasing an MQA album in a format such as FLAC, will consumers be able to convert the files, using software they already own such as JRiver, XLD, or dBpoweramp, to another format such as WAV or AIFF or ALAC without destroying MQA features of the file?

 

 

Put another way, if I convert an MQA FLAC file to AIFF, using JRiver Media Center, will the MQA light still illuminate on my DAC when playing the AIFF files?

 

Hi Chris

 

This question can be answered due to the 24 Bit transparency of AIFF, ALAC, WAV and FLAC.

 

You can convert (or should I say, you should be able to) the MQA FLAC file one hundred times between AIFF, ALAC, WAV and FLAC to any version, and when playing back, the MQA led should / must “shine”.

 

More interesting would be, will there be a software decoder, that could convert the MQA “packed” file, into a “pure” 352 or 176 kHz PCM file, or speaking, unfold the MQA origami for non MQA DACs or for DAWs.

 

Juergen

[monteverdi]

As I likely never get decoding on the DAC level for my equipment (Devialet) how much one loses in sound quality if the decoding is done via music server / computer. As I consider time coherence (including lack of pre/post ringing) the most interesting feature of MQA, how much of that can that preserved without a MQA certified DAC?

What about DSP features (like speaker correction and x-over)? Which type of connections will be possible USB, SPDIT AES etc. ?

[jabbr]

Are you willing to produce more technical documents describing the technology? The more details the better.

 

Are you willing to give a specific, technical explanation of the terms "temporal deblurring"? Can you explain if and if so, why, your apodizing filters are unique from a mathematical perspective?

[Jud]

Re the filters: Many apodizing filters start working in the high audible range in order to use a gentler slope. You've pointed out the importance of response to 45KHz. How will you be able to obtain this frequency response and avoid both ringing and undue aliasing distortion?

[R1200CL]

MQA has developed a test card.

Can this be phurchased by DIY's ?

If no, why, if yes, expected price.

 

Can we have some more technical documentation about the test card ?

[R1200CL]

Is the MQA technology still under development?

 

Where do you think MQA is a year from now ?

 

Is there a marked for MQA in streaming movies in order to achieve better sound ?

 

Can you tell us what went wrong during Auralic's MQA release under CES ?

(The use of a default DAC profile ?)

 

Will there be DAC chips available with built in MQA, and when ?

 

If yes, that also mean a DIY in theory can built a MQA DAC ?

[Totsipaki]

My questions are very simple and not Technical at all.

What is the time Schedule for MQA streaming release? Are any major Labels incorporating this kind of encoding?

Will there ever be MQA releases in physical format that can be ripped? I'd rather buy something in physical form especially if it is Premium priced and then rip It into my computer.I am one of those guys who would like to hold what they pay for.

 

Regarding my Disappiontment form hi res audio (with some exeptions of course) as a holy grail digital format I believe that MQA is the last format standing between Real evolution in digital audio and redbook-mp3 total domination in the long term.

 

Despite Us audio buffs (Wwho tend to listen with our minds rather than our ears) nobody will really care about hi-res enough to make It something Special in the Market and in my opinion rightfully so. The only hi res formats that really make a difference are so large that makes them totally unconvenient to store stream or even listen to. To my experience all other digital formats exept DSD128/DXD offer little if any improvement over redbook depending on the recording.

 

MQA is truly the last chance for something really Special to happen. I sincerely hope that all those frustrating delays mean that It's release will be something Special including major support from the Real music Industry and not just Niche audiophile labels. If It doesn't come to the music most people like to listen to It will not go far I am afraid, and I would like to think that It will.

[R1200CL]

What are the technical requirements for a certified A/D converter?

 

Can you explain the difference between adding MQA during mastering process vs recording ? As an example, does during recording mean that the original file already contain MQA, and a non MQA will not exist ?

 

Your FAQ about CD/DVD says:

"Yes, but this requires further explanation so that the content owner understands exactly " ( Sorry: Could not copy all text. Your web site has huge problems with iPad)

 

Can you take the time here to explain ?

[essem]

I'd like to ask about MQA decoding. Does it require hardware, software or both? Will there be a Linux software decoder library which will be able to be incorporated into the existing linux audio ecosystem (perhaps something similar to how Nvidia provides proprietry graphics drivers for its video cards to the Linux community)? Can you indicate what sort of licensing fee, if any, might be required for the enthusiast running their own Linux music playback system for personal use who would like to be able to decode MQA. Many thanks for any enlightenment.

[jzahr]

Thanks for the opportunity

 

My questions:

 

I.

There are many hobby recordists who use fairly respectable semi-pro (or even pro) digital recorders. In many cases these recordings are then subjected to some amount of post processing in the computer (eq, dynamics or some other digital processing for cleaning or “improving” the recorded audio) with the aid of plug-ins in DAWs:

 

-- Will the MQA de-blurring algorithm be available for purchase in plug-in form as a standalone package (i.e. without the “audio origami” folding compression technique)? If yes, this will allow for these kind of users to compare the MQA de-blur algorithm with offers from other manufacturers (like Waves or Izotope) that also claim to help to clean or improve the recorded digital audio.

 

II.

It has been stated that MQA enabled ADCs will be available for the pro market (think Mytek):

 

-- Will these ADCs be delta-sigma based with decimation for PCM output?

-- If yes, where in the conversion stage will be MQA participating with its de-blurring technology: is it in the decimation stage?

-- As a summary: what will be the main technological difference between a top-nocht MQA certified ADC and the already existing top-notch non-certified ADCs like Meitner, Merging, Metric Halo or Apogee.

 

III.

To me, it is very important to allow every content creator work in the format in which feels more comfortable with. While the majority of music producers and recording engineers work mainly in the PCM world, there are some that prefer to work instead in a purely DSD domain (or some analog-DSD combination). Of course, there is conversion software that allows to release a final musical product in any format, but my question is:

 

-- Does the MQA technology, as a whole, fit in a production environment based mainly or purely in DSD?

-- If yes, in what way?

 

Thanks,

Jorge

[jabbr]

The use of deconvolution filters to improve spatial resolution, essentially to deblur, dates back many decades. I find references dating back to the 1950s regarding seismological data, and of course optical. Norbert Weiner (1) specifically describes using time sequences. Is this "temporal deblurring"? If not what aspect of your own temporal deblurring is fundamentally different than a deconvolution?

 

(1) Wiener N (1964). Extrapolation, Interpolation, and Smoothing of Stationary Time Series. Cambridge, Mass: MIT Press. ISBN 0-262-73005-7

[lmitche]

My questions:

 

When will the MQA certification process for third party DAC partners be complete, such as the Mytek Brooklyn?

 

Where can recordings be found where the recording process was performed using MQA compliant ADCs?

 

Will a MQA decode software module be available for integration into third party music players that run on generic PCs and Macs?

[jeffmudrick]

To the extent that hardware decoding is necessary or desired and that many DAC manufacturers might not be able to incorporate hardware mods, could an MQA decoder in a box feeding into a DAC be a potential solution for consumers?

[The Computer Audiophile]

The thread is now closed to questions