This writeup was originally posted to /r/hobbydramma in October 2022, and has since been deleted. This version has been slightly edited for improved clarity and to add some new details that have developed since I made the original post.

Some Background on Digital Audio

This section might get a bit technical, but it’s essential for understanding the nature of this controversy. I’ll try to keep it as simple as possible.

Audio, like most forms of media, can be encoded digitally in a number of different ways. One of the key distinguishing features when comparing digital audio formats, is whether the encoded audio is lossy or lossless. Lossless audio formats store encoded audio signals in their entirety. When decoded, lossless audio is indistinguishable from the original unencoded signal. By contrast, lossy audio formats produce a signal that is close, but not quite identical to the original, hence they “lose” information. This loss is usually intentional, and is done in order to reduce file size at the cost of sound quality. Here is an image showing the difference between .flac (lossless) and .mp3 (lossy) files of the same recording. It should be noted that even the tiniest difference between encoded and decoded audio signals make a format lossy. True lossless formats must always produce a 100% identical signal to what was originally encoded. Unsurprisingly, audiophiles tend to have a strong preference for lossless audio formats.

Not all lossless audio is equal however. Audio from a standard music CD plays 16-bit samples at 44.1KHz. This is very good quality, and has become something of a lowest common denominator for lossless digital audio. Exceeding CD-quality audio is possible, and it’s something audiophiles are often keen to do. This “Hi-Res” audio almost always uses 24-bit samples, which are played back at anywhere from 48 to 192KHz. You can think of these different standards as being sort of like the difference between 1080p and 4K for video. Ideally, Hi-Res lossless files should always be created directly from an original studio master, which is the highest quality version of a recording that will ever exist. These “master quality” files, are preferred over all others by a large number of audiophiles.

MQA

MQA stands for Master Quality Authenticated. It is a digital audio format designed by Bob Stuart and his company Meridian Audio. MQA was released under MQA Ltd., a company founded specifically to manage this new format. The goal of MQA was to improve sound quality for the average listener, and set an industry-wide standard for the storage and distribution of high resolution digital audio.

The idea behind the MQA format is that high frequencies, such as those found in 24-bit Hi-Res audio files, are compressed or “folded” into a lower resolution, 16-bit audio stream. According to MQA Ltd., MQA encoded audio will work with just about any digital audio decoder, and will play at the same quality as a normal CD. However, if the audio is played back with a special MQA decoder, the audio stream will be “unfolded” up to three times, with each unfold adding resolution and depth to the reproduced sound. Allegedly, this technique allows MQA to achieve “studio quality” and “retain 100% of the original recording” The folded 16-bit audio stream can be used to create special MQA CDs that are still compatible with regular CD players. Additionally, MQA technology allows music download and streaming services to serve up 24-bit Hi-Res audio, while keeping data usage about the same as what’s needed for regular CD-quality lossless.
The real selling point though, is in the “authenticated” part of Master Quality Authenticated. Using sound signature testing and watermarking of the audio signal, MQA can, at least theoretically, compensate for distortion and other artifacts introduced in the recording, mixing and mastering process. In an ideal scenario, MQA should be able to make audio sound identical to how it does in the studio, as if there are no recording or playback devices in between. This process is also meant to validate the authenticity of MQA files, ensuring they have not been changed or tampered with at any point between the mastering studio and the listener.

MQA was first revealed to the public in December 2014. By mid-2016 Warner Music Group had struck a deal to license MQA for their releases, and the first audio hardware with built-in MQA decoding was hitting the market. Around the same time as the Warner Music deal, the RIAA gave MQA it’s official Hi-Res certification, allowing MQA releases to feature the Hi-Res MUSIC logo. In the following months, more record labels, including Sony and Universal, signed on to release their music in MQA. The biggest boost for MQA however, came in January 2017, when Jay-Z’s Tidal streaming service announced that it would soon support the format. Tidal was already popular with audiophiles for being among the first to offer lossless music streaming, and now they were set to be at the forefront of this emerging Hi-Res standard. With superior sound quality, the backing of big record labels and manufacturers, a major streaming service on board, and loads hype from the Hi-Fi press, it looked like MQA would soon be a staple of the high-end audio world.

Initial Backlash

Despite it’s apparent advantages, and some claiming that MQA encoded files sound better than their vanilla 24-bit counterparts, there were a number of people firmly against MQA from the start. Early criticism mostly came from individuals within the music industry, who noticed a number of concerning things surrounding MQA and it’s business model, and their sentiment slowly spread to the wider audiophile community.

The biggest concern with MQA early on was the proprietary nature of the format. MQA is defined and controlled entirely by MQA Ltd. Unlike most other Hi-Res audio formats, hardware manufactures, software developers, record labels, and streaming services all have to pay licensing fees if they want to support MQA. Now, the music and Hi-Fi industries are no strangers to this business model. Charging a licensing fee for music formats dates back at least as far as the CD, however, MQA’s licensing structure is incredibly restrictive and controlling compared to most others. To start with, any product that supports MQA has to be certified by MQA Ltd. for compliance. This can be hard on equipment manufactures, who sometimes have to redesign hardware, or rewrite firmware to get MQA’s blessing. On top of that, MQA audio won’t unfold to it’s full resolution unless every stage of the audio supply chain, from mastering, to distribution, all the way to the end-user’s hardware are MQA certified, and you better believe MQA is collecting royalties every step of the way. If that wasn’t all bad enough, MQA hardware licenses are sold per-unit, so economies of scale can’t help to offset licensing costs. Even worse, is that third party software decoders are charged per decoded track. As a result, products that support MQA are invariably more expensive than their non-MQA counterparts.

Due to these licensing issues, Schiit Audio issued a statement explaining that they would not be supporting MQA, and several other small manufacturers took a similar stance. Another company, PS Audio, did add MQA support to their hardware, but later released a video that was very critical of the format. This video reveals that MQA support was added entirely due to customer demand, so it’s clear the format had a good number of supporters, at least early on.

Excessive licensing costs weren’t the only concern surrounding MQA though. MQA is touted as being DRM free, with audio streams able to be stored in the very popular, open source FLAC format. Only the lower resolution 16-bit audio is truly DRM free however. MQA’s authentication watermarking must be present in the file, and properly validated at playback, otherwise MQA decoders will refuse to unfold the audio to it’s full resolution. In this way, MQA acts as a sort of “soft-DRM”, that prevents recordings form being played at their maximum quality without both permission from the rights holder, and validation from MQA Ltd. All the issues surrounding MQA’s licensing and copy protection are explored in more detail in this article from 2017.

The Problems Run Deeper

If licensing and DRM were the only problems that plagued MQA, the format would still have it’s detractors, but it would probably be able to maintain a certain level of support amongst artists and music fans. As MQA hardware made it’s way into the hands of reviewers and audio technicians however, it became clear that there was something fishy about this new format.

When it comes to digital audio formats, even propitiatory ones, standard practice is to give reviewers and other people within the industry access to an encoder, or even release one publicly. This is so that people testing out the format can encode whatever they want with it, and compare the output side-by-side with the input. The results of these tests are important for a format to build trust and gain adoption within the high-end audio community. It might come as a surprise then, that MQA Ltd. did not make an encoder available to anyone at launch, and still hasn’t released one to independent third-parties to this day.

The lack of an encoder raised a few eyebrows, and suspicions about MQA only deepened once people realized that the format had been made as difficult as possible to validate. For example, MQA’s license terms forbid sending unfolded MQA data over a digital connection. A digital output could be used to capture raw audio samples and check them against a non-MQA source, but all MQA decoders send unfolded data straight to an internal DAC that only outputs analog signals. People, of course, figured out other ways to capture MQA audio signals, and began noticing some very odd things about them. There’s a great article that goes in-depth about various MQA test results, but the upshot is that audio signals derived from MQA files appear to contain all manner of excess noise and artifacts that should not be present in a lossless format.

MQA is lossless? Right?

Well, MQA’s official website plainly states that the format is lossless, as does their original logo. On top of that, in a 2016 interview about MQA, Bob Stuart was quoted as saying “…we focus solely on strict lossless delivery” and “…the [packing] process is losslessly reversible for the encapsulated audio and even at the lowest transmission rate”. Also, remember how the RIAA gave MQA it’s “Hi-Res” certification? Well, that certification is only supposed to be given to lossless formats. The RIAA defines high resolution audio as “lossless audio capable of reproducing the full spectrum of sound from recordings which have been mastered from better than CD quality music source”. Given all that, MQA had damn well better be lossless.

The Real Controversy

Now this may come as a shock, but MQA is not a true lossless format, of course this wouldn’t be a hobby drama post if it was. The technique MQA uses to pack high frequency data is not without side effects, the most obvious one being ultrasonic “reflections” of audible sound in some unfolded tracks. Taking a look at this graph, we can see a gap in the audio data at around the 22KHz mark. That gap should not exist, because none of the data on the right side of the gap was present in the original track, it was all added during the MQA unfolding process. Other side effects include aliasing, ringing, and a higher noise floor. Even if you don’t understand what all those things mean, just know that they’re generally not good. It was also revealed that MQA’s folding process always causes these side effects to some degree, regardless of the source audio’s sample rate, or whether or not it’s unfolded during playback. That means that CD-quality recordings will always sound worse when encoded in MQA, and file sizes are often larger than their regular FLAC counterparts.

In addition to not being lossless, A user on the Audiophile Style forums discovered that MQA’s authentication mechanism doesn’t even validate the whole file. Up to a third of the audio data can be completely removed from an MQA file, and an MQA decoder will still authenticate it. This means that MQA’s authentication scheme is effectively worthless. Theoretically, a streaming service could truncate MQA files to save on bandwidth, and an MQA decoder would still report the audio as coming from an authentic, Hi-Res file that has not been modified.

Once all this information started coming out, MQA became a target of ridicule for a certain portion of the audiophile community. A thread on the Audiophile Style forums titled MQA is Vaporware currently sits at over 1,000 pages, and contains comments such as “If they want a scam that the consumers might go for, how bout a streaming service that streams from original source vinyl?” and ”Maybe TIDAL and MQA can merge and get an executive from Sears to mismanage the whole thing into the abyss.” It was also around this time that some music piracy communities started imposing bans on MQA sourced content. Following the backlash, MQA Ltd. quietly removed any mention of the format being lossless from their website, but a handful of angry audio nerds wasn’t a large enough controversy to halt MQA’s slow, but steady adoption across the industry.

The Drama Intensifies

Rocky Mountain International Audio Fest was an annual audio industry trade show. At RMIAF 2018, Chris Connaker, an audio manufacturing consultant, gave a talk on MQA, in which he aimed to discuss the pros and cons of the format in an impartial manner. This wouldn’t be particularly noteworthy, if it weren’t for the fact that multiple MQA executives were in the audience. Once Chris starts talking about how MQA is not a lossless format, Ken Frosythe, the marketing director of MQA Ltd., chimes in to try to discredit his source. This completely derails the presentation, as Chris and Ken proceed to argue back and forth for nearly five minutes. Eventually, Derek Hughes, an MQA proponent with no direct ties to to the company, speaks up to ask his own clarifying questions. Chris can’t even finish responding before Mike Jbara, the CEO of MQA Ltd., jumps in. Mike berates Chris for intentionally misrepresenting the MQA standard, and criticizes him for not including Bob Stuart’s responses to the points he’s brought up. During his diatribe, Mike makes the bizarre assertion that “…trying to represent an objective end-to-end review of MQA on a spectrum, is just a silly representation of your own opinions.” There’s more back and forth, and by the time Chris finishes responding to Mike, the presentation is almost halfway over and has gone entirely off course. Chris tries his best to continue, but he is repeatedly interpreted by these same three individuals. They take issue with nearly all his criticisms of MQA, and throw out accusations of bias until he eventually gives up. This absolute shit show was recorded in it’s entirety ,with the highlight being a clip of Derek Hughes banging on a table while shouting about DRM. This became a minor meme following the event. Derek later tried to defend his actions, but ultimately apologized for his behavior.

The RMIAF presentation was not the last time Chris Connaker would butt heads with MQA representatives. Chris also runs the Audiophile Style website, which is home to multiple in-depth articles and discussions about MQA, several of which have already been linked in this post. In May 2019, Chris revealed in a forum comment that people from MQA Ltd. had attempted to have content on the website removed on at least one occasion. The post’s conclusion reads ”Some people have expressed an interest in censoring content here and can you believe one’s name is Bob Stuart?” One particular user was not happy about this revelation, not because of the alleged attempts at censorship, but because Chris was encouraging a “hate fest”. His comments were called out by other users, and eventually marked “off-topic”. At this point, the consensus among most forum members was that MQA did not live up to it’s claims, and that the people behind it would go to great lengths to try to hide that fact.

While MQA continued to be adopted, and it’s detractors slowly grew in number, the next major development in this story wouldn’t come until 2021. At the beginning of that year, musician Neil Young announced that he was having his work removed from Tidal. Tidal had labeled Neil Young’s albums as “Masters”, a designation given to high resolution MQA releases on the service. The problem was, that Tidal had never been supplied with high resolution versions of those albums, CD-quality lossless should have been the only H-Fi option available. Upon further investigation, it was discovered that Tidal had taken the 16-bit lossless files they were given, converted them to MQA, and made them available to stream as “Masters”. They then removed the superior 16-bit lossless versions from their service, all without the knowledge or permission of the artist. This wasn’t an isolated incident either. It turns out Tidal had quietly replaced albums from hundreds of well known artists with inferior MQA versions. What’s worse, is that end users had no easy way of telling which tracks had been converted from CD-quality, and which were actually sourced from a Hi-Res master. Even people who were on board with MQA, now had zero assurance that anything encoded in the format was in any way master quality. A number of smaller artists joined Neil in having their work removed from Tidal once this all came out.

Enter GoldenSound

GoldenSound is YouTuber who makes videos covering high-end audio equipment and related topics. In April 2021 he uploaded a video about MQA. The video is very well produced and goes over much of the same information I’ve covered here so far. The thing that made GoldenSound’s video stand out though, is that he found a way to fully validate MQA, despite not having access to an encoder. Tidal, like most streaming services, has an automated submission system for independent artists. People using this system can get their music published in MQA on Tidal if they submit a high resolution master. GoldenSound took a bunch of high resolution test signals and submitted them though this process. Initially, Tidal rejected his tracks, presumably because they had a system to check for test tones, but after combining them all into a single track interspersed with actual music, his submission was accepted. GoldenSound was then able to stream the MQA tracks from Tidal and compare the signal output to the master he submitted. What he found was 100% confirmation of what people already knew; MQA was a lossy format, who’s encoding process added all manner of distortions and a substantial amount of noise, even in completely silent portions of tracks. He also found that MQA created from a CD-quaily source sounds audibly different than MQA created from Hi-Res, even with the exact same audio data in the source files.

GoldenSound actually sent his findings to MQA Ltd. prior to uploading his video. What he got back was a ban from Tidal, and a lengthy e-mail that consisted mostly of marketing copy and weak attempts to refute his results. The parts of this e-mail worth addressing are fairly technical, so I won’t get into them here, but GoldenSound does a good job going over them in the final part of the video. The main takeaway form this response is that MQA Ltd. continues to react with extreme hostility towards anyone criticizing their format.

GoldenSound’s MQA video quickly spread throughout music and audiophile communities, and the Streisand effect went into full-swing. Articles were written, memes were made, and many discussions were had. There was also a disclaimer added to that previously referenced Bob Stuart interview that reads “Most of Bob Stuart’s answers have been debunked and the MQA technology is now seen as lacking any benefit for anyone other than record labels and MQA Ltd.” People who had never heard of MQA before were now decrying the format and canceling their Tidal subscriptions. A bunch of new people found Chris Connaker’s RMIAF talk, and were outraged by the behavior of the MQA executives. MQA Ltd. went into full damage-control mode, with Bob Stuart himself issuing a public statement that was clearly a response to GoldenSound’s video, despite never directly addressing it. Press outlets that had been previously been positive on MQA also began publishing new articles talking up the format.

MQA Ltd. went one step further with their attempted damage-control, when someone, presumably tied to the company, tried to edit the MQA Wikipedia page to downplay criticism of their format. These edits included removing references to GolenSound’s MQA video, removing any mention of the format being lossy, removing information about DRM concerns, changing information about how MQA works, and even publicly doxxing GoldenSound. These changes were all sensibly reversed by Wikipedia’s editors, and none of them remain on the MQA page today.

About a month after his MQA video, GoldenSound posted a followup, in which he address the public response made by Bob Stuart. GoldenSound handled each point of criticism in an extremely clear and professional manner, and throughout the video, he makes pleas for increased transparency and further testing of MQA. The most interesting nugget from this video, is that, according to Bob Stuart, MQA is optimized to only work well with “natural sounding” music, which is why GoldenSound’s prior tests had such poor results. Even if this is true, it’s not a good look for a format that’s meant to be studio quality, especially when you consider that it’s likely to be used for things like electronic and industrial music. The video concludes with the promise of another followup, if anyone from MQA Ltd. follows through on the requests for more transparency. A second followup video has never materialized, and most audio enthusiasts have remained firmly opposed to MQA in the time since.

Aftermath

While MQA is still around today, and you can still buy new Hi-Fi equipment with MQA support, it’s much less of a selling point than it was a few years ago. A large portion of audiophiles have sworn off MQA, or just never used it in the first place. There are still a few MQA die-hards who have doubled down in their support of the format, but they seem to be in the minority. The controversy has damaged the reputation of just about everyone involved with MQA Ltd., particularity Bob Stuart, who was respected by those familiar with his work prior to MQA. Conversely, GoldenSound has become a well respected figure among audio enthusiasts, and has more than doubled his YouTube audience off the back of his two MQA videos. Today, MQA is often seen as a “snake oil” product, in the same category as things like CD demagnetizers and audiophile ethernet cables.

In June 2021 Apple Music added a lossless option to their service. This move has made lossless and Hi-Res audio a less viable niche for smaller competitors like Tidal, given Apple’s larger catalog and better brand recognition. Apple is using their well established ALAC format for steaming, a decision which effectively killed MQA as a competitive option for streaming services. In June 2023 Tidal announced that they will be switching to FLAC for Hi-Res audio streams, and the future of MQA Ltd. looks uncertain as a result. In a few more years MQA is likely to join HDCD and DVD Audio in the pile of dead Hi-Res audio formats.

The ultimate irony in all of this, is that due to the limits of human hearing, Hi-Res audio probably doesn’t provide a tangible benefit to listeners in the first place. But, that’s an entirely separate debate that has been raging in the audio community for decades at this point.