MQA: Is This Codec Masquerading As High Quality Audio?

I recently did some research into the MQA codec and ended up going further through the looking glass than expected.  

MQA – Master Quality Authenticated – is an audio technology developed by Bob Stuart, co-founder of high end hi-fi manufacturer Meridian Audio. MQA enables delivery of studio-quality sound in digital files small enough to be streamed. 

High-res files are huge. Most of the file above a certain frequency is noise and, because linear PCM treats all information in the file as equal, this makes high sample rate files hugely inefficient, especially for streaming. Thus the allure of MQA; its ability to fold big files into smaller more manageable sizes, but retain all the “good parts” when unfolded at the end.  

MQA also guarantees a direct link between artist and listener in the form of an authentication feature. On playback device that supports MQA, a green light indicates the file is MQA, and a blue light indicates the MQA file has been approved at a studio or copyright owner level. So at first glance MQA is a high quality audio format that comes in a manageable size, and even promises to enhance existing audio by fixing errors in the authenticated original recordings and masters.

Sounds awesome! But is it?

Down, down, down.

According to whichever online rabbit hole you go into, it's either THE technology to make hi-res audio streaming a reality, or it’s a cynical, calculated “land grab” by MQA and big music labels to establish themselves as toll collecting gatekeepers for high quality audio. There's been a lot of interest in the tech since its announcement in 2014, and more so with streaming service, Tidal adopting in early 2017. So is MQA all it is hyped up to be? As it turns out, that is very hard to find out.

The reason it’s very hard to find out is because MQA has a completely divided base of detractors and supporters, and we’re not talking about anonymous audiophile forum users spitting on screens in neckbeard fury, we’re talking about heavyweights in the industry who either love it or hate it. 

At the start of researching this article, I felt like Alice going through the looking glass, but now I feel like Humpty Dumpty teetering precariously on the fence, unsure of which way to fall. On one side you have MQA itself, a perfect sheen of cutting-edge tech savvy and marketing prowess, with a bunch of high profile audio journalists and mainstream companies buying into and supporting their platform. On the other side you have high-level tech developers, reputable high-end manufacturers, and ultra-boutique hi-res audio services vehemently opposed to the whole idea.

So what is going on? 

For audio geeks, the MQA folding technology is fascinating. The metaphor they use is audio origami, “...essentially folding up a piece of paper, sending it across, and then unfolding it again so nothing is missing.”

Oversimplified, in a high sample rate file (96kHz/24 Bits and up), 5/6th of it is “just noise” above 50 kHz. MQA folds that high frequency information into the noise floor of a typical consumer sample rate (44.1 Khz/16 Bits), and then unfolds it back into the higher sample rate when decoded with the appropriate gear and software. If no decoder is found, it simply plays back at CD resolution meaning an MQA file is backward compatible and is not crippled by the lack of a decoder, the file’s high-res information is simply kept tucked away in whatever lossless wrapper the file came in, be it ALAC or FLAC etc. The best of both worlds it seems.

MQA has gone to considerable lengths to factor in psychoacoustics too. They specifically address an issue in digital audio called temporal blurring, so their compression deals with both the time and frequency domain. Due to digital limitations far too complex to go into here, digital audio suffers an unnatural phenomenon called pre and post ringing where recorded sound energy builds up before a sound actually begins and continues after the sound has stopped, something that is not observed in natural/live sounds. Post ringing - if observed naturally - is thought to be "covered" by the sound itself.

In other words, a digital signal tends to be spread out over a time longer than the original, and we may just be able to pick up on this unnaturalness. Existing studies into human sensitivity show the human ear can resolve timing issues of of 10µs or less, well within the time frame of measurable blurring. Through processes beyond the scope of this article MQA purports to address this issue, and they even claim to be able to compensate for “pollution” in the original masters. 

According to proponents, MQA sounds fantastic, but these sonic benefits are anecdotal and have yet to be proven empirically, but enough well respected ears in this field have come back with praise, so I am willing to give the benefit of the doubt on that front. Besides, I have not yet heard MQA on a compatible system so I cannot comment on that anyway.

But there are some other observations to make, unrelated to hearing, that raise the proverbial eyebrow about the other, supposed benefits of MQA. This is where the audio geek in me signs off, because at this point a few shadows fall across the whole endeavour, and MQA itself is casting them.

By far the darkest shadow is the level of control MQA needs to do what it does. Many consumers and manufacturers alike are hyper skeptical of the business model MQA is folded into, especially the amount of influence MQA will have over the industry if fully adopted. MQA vehemently deny the obvious implications of how their “end to end quality control ecosystem” could be turned into DRM, or be used to discriminate other equally viable audio options. They focus acutely on “quality”, but the “control” aspect is heavily buried within marketing noise. 

MQA itself may have good intentions now, but what happens if they get bought out by a larger entity with a less naive approach to the control tools MQA are so eagerly trying to install at every stage of music making, distribution, and consumption? Bob Stuart does seem quite sincere in his efforts to improve audio streaming quality, but there is genuine concern that his corporate partners and shareholders are after much, much more. 

I was willing to give MQA the benefit of the doubt on this front too until, through sheer synchronicity, I bumped into an audiophile at an art exhibition in Frankfurt who owns a Meridian Audio theatre system, and of course I immediately asked him his thoughts on MQA. His reply? “Ahh Meridian, the proprietary island.”, and he rolled his eyes. The conversation pretty much ended there.

Proprietariness is a core aspect of Meridian Audio, from non standard speaker connections to (obviously) tightly kept DSP secrets, and even though Bob Stuart goes to great lengths to point out that MQA is an entirely separate company from Meridian, it is no leap of the imagination that this “lock a customer into our ecosystem” business concept permeates MQA, and of course it is always for the greater good of the consumer. It's a smoother ride, as long as MQA holds the steering wheel the whole way of course, and collects a little gas money on the side for the trouble of driving your car for you. Understandably a whole bunch of people have an issue with that.

Another area of contention is MQA’s dance around the lossy nature of their codec. When the topic comes up, one gets the sense of dealing with the Cheshire Cat – a grin without a cat so to speak. Why? According to many experts, the math doesn’t add up, so why not just be upfront and say it’s a lossy format? Point out that it has massively greater benefits over traditional lossy formats - under the right playback and licensed conditions - and that the true benefits are primarily psychoacoustic phenomena.

And speaking of psychoacoustics, it is also pertinent to note that most advocates of MQA seem to have had the tech demoed to them on extremely high end Meridian gear, equipment designed to solve many of the issues MQA claims to “fix”, specifically time domain issues inherent in both digital and speaker designs. Listening to before and after files carefully prepared by MQA, on top-of-the-range systems costing upwards of $40 000, raises the question of whether it was the quality of the playback system rather than the benefits of MQA itself they were hearing.

All The King's Horses…

Should indie musicians, beat makers, and bedroom producers even care? No, not yet, unless you have a 40,000 dollar sound system in your lounge. It’s best to focus on great ideas, dynamic mixes, and watching those LUFS levels. Keep that music flowing. Also, personally, as an artist and music creator, I find myself throwing up into my mouth a little at the whole “artists are so important, and we care” schtick that pervades MQA and mainstream audio marketing, a saccharine rhetoric that has no real world benefits to the average artist – unless of course that artist owns the streaming service adopting MQA tech. 

At least the music will sound good amiright? In my humble opinion, music needs another proprietary hoop to jump through like Humpty Dumpty needs another wall, so this “egg” is quite happy to remain on the fence for now.