MQA draws on recent research in auditory neuroscience, digital coding and in the perception of high-quality sound.  [1]
Our ‘Origami’ folding technology creates a single, compact, efficient, streamable MQA distribution file with no playback restrictions, that can be used for download or streaming and enjoyed in many different situations including mobile, in-car, on a PC, with a Hi-Fi and so on.
The MQA file can be fully unfolded to recover the exact sound of the studio preview using a Full Decoder. To add convenience, unfolding can proceed step by step, enabling a number of intermediate quality steps, each of which can be previewed in the studio and Authenticated.

Generally, MQA decoders automatically ‘unfold’ as far as the hardware permits.

Unfolds	Each playback option can be previewed in the Studio and Authenticated.
	No decoder? You don’t need a decoder to enjoy our ‘standard’ sound quality – which is now widely agreed by mastering communities to be superior to CD. Authenticated: Where the hardware is limited to single rate playback (44.1 or 48 kHz) the decoder prepares the signal to give the maximum sound quality from generic D/A converters.
	MQA Core: The first unfold of the Origami recovers all the direct music-related information and makes it available for either analogue or digital output at 88.2 or 96 kHz. Sound quality is higher than from ‘No’ or ‘Authenticating’ decoders but lower than a ‘Full’ decoder. Products containing an MQA decoder may provide a digital output of either the undecoded stream or the Core output – providing they are passed with bit accuracy. The MQA Core signal is also preconditioned for generic DACs.
	Full Decoder: A full decoder includes: stream Authentication, Origami unfold to Core and then further unfolds with precise file and platform-specific DAC compensation and management according to the hierarchical target. This is the highest possible sound quality.
	MQA Renderer: This new class of device can take a bit-accurate signal from a Core decoder (containing buried information on how to proceed) and complete the final unfold in its analog context. An MQA Renderer will indicate ‘stream lock’ but is not able to decode an MQA stream or Authenticate it. This type of device is available for portable applications (such as active headphones or portable amplifiers) and for silicon integration. MQA Renderers provide analog output only through their managed D/A conversion.

Q1. What are practical advantages of a full decoder with DAC?

• MQA streams will not always arrive via a Core decoder. Although some applications and services may include a software MQA Core decoder, MQA files and streams are expected to arrive from many different routes including music servers, file streamers, live streams, over WiFi, from set-top box or even optical disc.
• MQA decoders should accept signals on all digital interfaces.
• Properly executed, a hardware decoder + DAC will always give superior performance.
• A full decoder provides maximum future flexibility for the user.
• A full decoder is able to indicate MQA Provenance and other information such as Original Sample Rate on its UI.

Q2. What are the practical advantages of software decoding?

• It is an advantage for a streaming service to provide MQA Core decoding on platforms which are not natively capable of high-sample-rate playback or which have other audio restrictions – such as a laptop, tablet or smartphone. The MQA Origami process can be exploited to get the highest possible sound quality in those contexts.

Q3. What are key features of an MQA Core output?

• MQA Core output from a decoder carries information enabling a downstream MQA Renderer to complete the Origami unfold and to provide a full output.
• The Core signal can be passed over interfaces such as Lightning or USB to low-power portable devices such as headphones and retain the possibility of very high-quality sound downstream.
• Since the MQA Core signal is at a higher rate (generally 88.2 or 96 kHz) a listener with a suitable DAC can enjoy a better (but not fully optimised) sound.

Q4. What are advantages of an MQA Renderer? 

• An MQA Renderer can provide a low-cost or lightweight upgrade for playback of music encoded in MQA.
• Some Class I USB devices can only receive 96 kHz audio. In these cases, a Renderer is able to take in the MQA Core and complete the unfolding up to 384 or even 768 kHz internally.

Q5. Why not make an MQA DAC that is a just a Renderer?

• When at all possible it makes sense to have an MQA decoder which gives decoding access to several signal sources. See Q1 above.
• An MQA Renderer is not able to display Provenance information.

---

Read more: Origami and the Last Mile – MQA CD

[1] Underlying concepts target the whole system from studio to home, analog-to-analog path and leap beyond a narrow digital-domain view of high-quality sound. For this reason, the highest quality MQA decoder tightly binds the D/A conversion into the final analog reconstruction.