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Again, these were posted online:

• a) MQA "folds" the double- and quad-rate audio data into the lowest bits below the baseband musical content of the 48/24 FLAC container. The "folded" MQA signal is fit into a 48/24 FLAC container for further compression. Undecoded MQA is claimed to restore the full baseband audio signal, but only to a bit depth of 16 bits, or 48/16. After all there are only 24 bits of resolution in a 24-bit FLAC container.

• b) How in the world has MQA fooled so many people into thinking that they could "fold" the…

We refer to the process by which MQA reduces high sampling rate signals to Fs = 44.1kHz or 48kHz as 'music origami', after the Japanese art of paper folding. Figures 14 to 16 show how it works for a 192kHz source.

Although the process is depicted here in two dimensions, it is actually a three-dimensional construct.

The first 'fold' (Figure 21) reduces the transmission rate from 192kHz to 96kHz, and the second (Figure 22) from 96kHz to 48kHz. The folding process is not filtering and the inherent sample rate and bit-depth remain. In the transport,…

This question was posed by some online commentators. We are giving a precis because the question has the wrong frame of reference.

Questions:

• a) MQA has publicly stated that the resolution of the baseband will depend on the spectral content of the music being encoded/decoded.

• b) By referring to widely respected Caltech Professor James Boyk's landmark paper on the high-frequency content of various musical instruments, "There's Life Above 20 kiloHertz! A Survey of Musical Instrument Spectra to 102.4kHz", we can easily see that all musical…

In the majority of our communication so far we have described one variant of MQA, while at the same time pointing out that the concepts, bitstream and system is hierarchical. What do we mean by that?

In fact MQA is hierarchical in a number of ways:

• The number of channels can be scaled upwards from 2.

• For music sampled at rates of 2x or higher, the playback sample rate can be optimised hierarchically by determining the 'unfolding' to suit the platform.

• The transmission rate can be scaled to be 1x, 2x, 4x or 8x. We have concentrated our…

Some misunderstanding has come from over-literal interpretation of our origami diagrams (which are intended to inform concepts for a general audience), misunderstandings of information theory and general lack of appreciation of the novelty in our advanced lossless data burying methods. Another source of confusion has come from commentators asserting that MQA executes the examples in some of our older patent applications. These factors led to a number of misunderstandings about MQA capability and some unsubstantiated assertions.

Unsubstantiated assertions from…

The Nielsen recording is issued by 2L and samples can be found on their website.[41][42][43]

As can be seen in the following, the inherent noisefloor of MQA in this recording is actually:

Without Decoder: MQA channel noise is lowest around 4kHz @ 17.5 bits with a channel capacity of 15.8 bits which has been shaped. The MQA noise is always below that of the CD release.

With Decoder: MQA channel noise is lowest around 4kHz @ 24.3 bits with a channel capacity of over 23 bits which has been shaped.

We have…

This graph examines the run-out noise (at around 5:24) for the original WAV file recorded by John Atkinson, MQA (with and without decoding) and the underlying MQA channel noise in this recording (also with and without decoding). Also shown are reference levels for 16, 18 and 20-bit TPDF dither in a channel sampled at 88.2kHz (footnote 1).

In the graphs the noise-floor curves overlay for both MQA decoded and Original master.

We can also see that the shaped HF noise introduced by…

As before, this graph examines the run-out noise (at around 5:24) for the original WAV file (peak and average), for MQA (with and without decoding) and for the underlying MQA channel noise in this recording (also with and without decoding). Also shown are reference levels for 16, 18 and 20-bit TPDF dither in a channel sampled at 88.2kHz (footnote 1).

Additional plots show the peak level in the recording for the original WAV file and for MQA (with and without decoding). This snapshot uses the same…

[1] Stuart, J.R., 'Soundboard: High-Resolution Audio', J. Audio Eng. Soc. Vol.63 No.10, pp831–832 (Oct 2015) Open Access www.aes.org/e-lib/browse.cfm?elib=18046.

[2] Stuart, J. R. and Craven, P.G., 'A Hierarchical Approach to Archiving and Distribution', 9178, 137th AES Convention, (2014). Open Access: www.aes.org/e-lib/browse.cfm?elib=17501.

[3] Stuart, J.R., Howard, K., 'New digital coding scheme—MQA', (Japanese translation by Hiroaki Suzuki), J. Japan Audio Society, Vol.55 No.6, pp45—57 (Nov. 2015).

[4] Lipshitz, S.P., Vanderkooy, J., '…

ADC (A/D Converter): Analog to Digital Converter.

DAC (D/A Converter): Digital to Analog Converter.

Encapsulation: The process which identifies and secures the information space of a music signal and which exploits advanced sampling and reconstruction methods to optimise analogue end-to-end temporal precision while minimising data rate. We refer to the encapsulated object as the 'kernel.'

Hierarchical Coding: A conceptual framework that models analogue as an infinite sample rate, finite word-size representation which can be approximated by a…