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JVS Cheerleads an MQA CD..Sis Boom Bah!


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18 hours ago, mansr said:

If he says there is any, sure.

How about these passages from Bob's post:

 

 

The Green signal is completely removed by MQA decoders; but it is there so that we can hear more of the music when playback is limited to a 16-bit stream. The coder for B uses an approximation (prediction) + a touch-up signal to make it lossless. The estimates of B1’ and B2’ can be buried within or below the green line (at the choice of the mastering engineer).
 fig28_fold2.png The next step is to fold this information into a small 48kHz 24-bit PCM file that you can hear wherever you play music today. If we don’t have a decoder this still sounds better than CD. This MQA file is low data rate – it is easy to stream and small to download. This encoded MQA file can also be previewed in the studio. We can play it on a Hi-Fi, a smartphone, a portable player, in the car, in a PC, on a Wi-Fi speaker or Bluetooth headphone.
This signal can be passed over a digital output to a downstream decoder. Decoders can unwrap the Music to give us as much quality as the playback platform can support. The same file supports Studio quality playback and a smartphone!
fig29_cdfile.png Sometimes we might want to listen to MQA music on equipment that doesn’t support 24 bits – maybe only 16? Rather than throw away all the buried information, MQA carries a small data channel (shown in Green) which can contain the ‘B’ estimates, enabling significantly improved playback quality on, e.g. a CD, over ‘Airplay’, in-car, to certain WiFi speakers and similar scenarios.
 If the target is a CD then specific coding is used to optimize the time-frequency balance and minimize the audibility of channel noise.  Of course, if your system handles 24 bits then the full file and dynamic range can be decoded.
 fig30_core.png  The MQA ‘Core’ contains and protects all the music information in the Triangle – and more besides. It also contains region C and additional information – buried as noise, in noise, far below audibility.
 A ‘Core’ decoder can unwrap back to this stage. In case the subsequent converters don’t go any faster, the MQA decoder has prepared this music for analogue replay. We can enjoy our music in 96 kHz 24-bit quality.  However, there is something special here. We can pass this 24-bit MQA Core signal on to another MQA device over USB, Lightning, S/PDIF, etc – and it is completely understood by a downstream MQA Decoder or MQA Renderer.
 fig31_unfold.png  An MQA Decoder will continue to unfold as shown. Region C is reconstructed using buried instructions, which may have been pre-determined by the studio mastering engineer. At this step, the MQA decoder also handles compensation and filtering of the following D/A converter, which, depending on the model, may contain a cascade of signal processing, upsamplers or other forms of conversion and filtering. 
 This step in the decode process will be different for every product, in order to make the resulting analogue conform closely to the hierarchical target and to most accurately replicate what was approved in the studio.  The rendering stage can, on certain platforms, use cross-family rate conversion to maximise quality and minimize analogue blur.
 fig32_mqa-1s-hierarchy.png  Showing the full system (analogue-to-analogue) average transmission kernel for the different decoding options shown in the previous two images. Olive is the full decoded result. When the transmission channel is limited to 16 bits, the decoder maintains good temporal performance, as the comparison between the olive and black curves show.  Audio below 20 kHz is maintained at full resolution, while some precision is lost in the next octave.
 If the final conversion to analogue is not using an MQA converter, the signals are preconditioned for a typical chip converter. The orange curve illustrates the input to the final converter if there is no decoder (‘Legacy mode’).  Blue shows the output of the ‘first unfold’ Core decoder at 2x speed. The orange and blue curves show the input to a DAC, not the analogue output.
 fig33_fouriertransform-of-hierarchy.png  Shows the Fourier transforms of the kernel responses in the previous image.
   
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27 minutes ago, testikoff said:

How about these passages from Bob's post:

 

 

The Green signal is completely removed by MQA decoders; but it is there so that we can hear more of the music when playback is limited to a 16-bit stream. The coder for B uses an approximation (prediction) + a touch-up signal to make it lossless. The estimates of B1’ and B2’ can be buried within or below the green line (at the choice of the mastering engineer).
 fig28_fold2.png The next step is to fold this information into a small 48kHz 24-bit PCM file that you can hear wherever you play music today. If we don’t have a decoder this still sounds better than CD. This MQA file is low data rate – it is easy to stream and small to download. This encoded MQA file can also be previewed in the studio. We can play it on a Hi-Fi, a smartphone, a portable player, in the car, in a PC, on a Wi-Fi speaker or Bluetooth headphone.
This signal can be passed over a digital output to a downstream decoder. Decoders can unwrap the Music to give us as much quality as the playback platform can support. The same file supports Studio quality playback and a smartphone!
fig29_cdfile.png Sometimes we might want to listen to MQA music on equipment that doesn’t support 24 bits – maybe only 16? Rather than throw away all the buried information, MQA carries a small data channel (shown in Green) which can contain the ‘B’ estimates, enabling significantly improved playback quality on, e.g. a CD, over ‘Airplay’, in-car, to certain WiFi speakers and similar scenarios.
 If the target is a CD then specific coding is used to optimize the time-frequency balance and minimize the audibility of channel noise.  Of course, if your system handles 24 bits then the full file and dynamic range can be decoded.
 fig30_core.png  The MQA ‘Core’ contains and protects all the music information in the Triangle – and more besides. It also contains region C and additional information – buried as noise, in noise, far below audibility.
 A ‘Core’ decoder can unwrap back to this stage. In case the subsequent converters don’t go any faster, the MQA decoder has prepared this music for analogue replay. We can enjoy our music in 96 kHz 24-bit quality.  However, there is something special here. We can pass this 24-bit MQA Core signal on to another MQA device over USB, Lightning, S/PDIF, etc – and it is completely understood by a downstream MQA Decoder or MQA Renderer.
 fig31_unfold.png  An MQA Decoder will continue to unfold as shown. Region C is reconstructed using buried instructions, which may have been pre-determined by the studio mastering engineer. At this step, the MQA decoder also handles compensation and filtering of the following D/A converter, which, depending on the model, may contain a cascade of signal processing, upsamplers or other forms of conversion and filtering. 
 This step in the decode process will be different for every product, in order to make the resulting analogue conform closely to the hierarchical target and to most accurately replicate what was approved in the studio.  The rendering stage can, on certain platforms, use cross-family rate conversion to maximise quality and minimize analogue blur.
 fig32_mqa-1s-hierarchy.png  Showing the full system (analogue-to-analogue) average transmission kernel for the different decoding options shown in the previous two images. Olive is the full decoded result. When the transmission channel is limited to 16 bits, the decoder maintains good temporal performance, as the comparison between the olive and black curves show.  Audio below 20 kHz is maintained at full resolution, while some precision is lost in the next octave.
 If the final conversion to analogue is not using an MQA converter, the signals are preconditioned for a typical chip converter. The orange curve illustrates the input to the final converter if there is no decoder (‘Legacy mode’).  Blue shows the output of the ‘first unfold’ Core decoder at 2x speed. The orange and blue curves show the input to a DAC, not the analogue output.
 fig33_fouriertransform-of-hierarchy.png  Shows the Fourier transforms of the kernel responses in the previous image.
   

 

This all looks strangely familiar from Bob's Los Angles Audio Show seminar (June 2017). That had a great ending, Bob being called a liar. Robert Harley too if I remember correctly.

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37 minutes ago, testikoff said:

How about these passages from Bob's post:

 

 

The Green signal is completely removed by MQA decoders; but it is there so that we can hear more of the music when playback is limited to a 16-bit stream. The coder for B uses an approximation (prediction) + a touch-up signal to make it lossless. The estimates of B1’ and B2’ can be buried within or below the green line (at the choice of the mastering engineer).
 ...............  

 

All this has been debunked in this thread and others.  Unfortunately there has not been a specific summery written for MQA "CD" as there has been for MQA in general I do not believe (like this):

 

 

 

Hey MQA, if it is not all $voodoo$, show us the math!

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3 minutes ago, testikoff said:

So is there any truth in Bob Stuart's statements regarding B (i.e. 22...44 kHz or 24...48 kHz out-of-band spectral content) "estimates" in 16-bit MQA-CD audio of recent Warner & Uni Japan releases?..

None whatsoever.

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10 minutes ago, mansr said:

None whatsoever.

Thanks for confirming. Is it fair to say that all the MQA-CD does is carry the original sampling rate of the PCM master + the preferred upsampling filter to be used by the MQA-enabled renderer/DAC?

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1 minute ago, testikoff said:

Thanks for confirming. Is it fair to say that all the MQA-CD does is carry the original sampling rate of the PCM master & the preferred upsampling filter to be used by the MQA-enabled renderer/DAC?

It also has the cryptographic "authentication" signature and may include some HDCD-like dynamic range extension data. Remember, this data stream is limited to one bit per stereo sample, so there's really not much space available.

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