Most people who have heard music recordings encoded with Master Quality Authenticated agree that it sounds really goood (footnote 1)but even they recognize that at least one major challenge remains: ensuring that listeners can actually get, in MQA format, the music they most love. I spoke with Spencer Chrislu, MQA's director of content services, about the company's efforts to meet this challenge.
Author's Note: We are grateful to Stereophile for the opportunity to address some frequently repeated technical questions appearing in comments to articles. Recently this has included misunderstandings about noise calculation, dynamic range, resolution, definition, music spectra, channel capacity, lossless processing and temporal aspects of digital channels.
To simplify this document we have grouped the topics and set them as questions and answers either as response, tutorial or axiom. Some months ago we published a comprehensive Q&A for an online forum and to avoid repetition we occasionally refer to topics already discussed there (see [37] in the "References" sidebar).J. Robert Stuart
Jim Austin briefly discusses MQA in his review of the Explorer2 in this issue, but a more complete description of MQA can be found in an article posted on Stereophile's website at the end of 2014.
MQA involves two fundamental concepts, discussed in a paper presented to the Audio Engineering Society in October 2014, the first responsible for a potential improvement in sound quality, the second responsible for a large reduction in the bandwidth required for storage and streaming of high-resolution files...
Digging MQA (from LR): Peter McGrath, Jason Victor Serinus, and Michael Fremer, with Bob Stuart anxiously looking on and Winai Pawitwatana behind. (Photo: John Atkinson)
CES 2016 marked the first time that three writers for StereophileEditor-in-Chief, John Atkinson; AnalogPlanet analog guru, Michael Fremer; and this Contributing Editorcould sit down in the same room with Bob Stuart of MQA/Meridian and spend a concentrated amount of time comparing before- and after-MQA encoded (Master Quality Authenticated) tracks.
Meridian's Bob Stuart at the Manhattan launch, showing the law of diminishing returns regarding increasing the sample rate of PCM encoding.
In almost 40 years of attending audio press events, only rarely have I come away feeling that I was present at the birth of a new world. In March 1979, I visited the Philips Research Center in Eindhoven, Holland and heard a prototype of what was to be later called the Compact Disc. In the summer of 1982, I visited Ron Genereux and Bob Berkovitz at Acoustic Research's lab near Boston and heard a very early example of the application of DSP to the correction of room acoustic problems. And in early December, at Meridian's New York offices, I heard Bob Stuart describe the UK company's MQA technology, followed by a demonstration that blew my socks off.