MQA at CES

[Hiro]

MQA downloads and perhaps MQA encoded discs will be nice too, but allowing the Internet to finally realize it's promise of high-quality music from around the world without lossy compression is what has me excited about the possibilities of MQA!

 

Hasn't it been actually stated that MQA isn't lossless?

 

I can't help but wonder why they just can't use a truly lossless encoder like FLAC for 24/96 streaming, as all players are already compatible with this format...

[Hiro]

It can be lossless, but also can be lossy. The main claim has been it is audibly lossless. In other words it throws away data, but you cannot hear it. It also claims by using superior filtering it can sound in some cases better than the original.

 

These claims seem somewhat contradictory IMO, as we are told that although some data are lost during MQA encoding, the files are audibly lossless (to the original), but sound different after the in-built MQA sweetening/filtering...

[Hiro]

In fact, it claims time domain superiority over standard FLAC by apodizing for preringing in the a-d and post ringing in the d-a with a compatible DAC.

 

That would explain why everyone would need to buy new DACs...

[Hiro]

Yes, isn't high level marketing grand?

 

In fact they would probably tell you the original poorly filtered AD step was lossy versus the real signal and their filtering magic can undo it to recover more accurately the original signal, then of course they will lossy encode it in a way you won't hear and it will still sound better than the original.

 

Well, they don't know what kind of filtering was done in the AD stage, and there are many different ADCs out there.

[Hiro]

Nobody "needs" to buy a new DAC for MQA

 

That's how I understood Fitzcaraldo215's post; in order to take advantage of MQA a compatible DAC is needed, not just a software player. This requirement doesn't exist with FLAC however.

[Hiro]

The filtering thing is a whole different discussion.

 

In my opinion the nifty encoding to reduce bandwidth and play like a CD on non-compatible equipment is the best thing about MQA. However, the bandwidth differences are not quite as large as it would first seem compared to 96/24 FLAC.

 

MQA compresses well (among other reasons) because it encodes the above 20 khz region with very few bits, because the majority of those bits nearly all the time are 0. They also are only providing best I can tell something like 30 khz bandwidth on playback because they say that is all that is needed to be psycho-acoustically lossless if filtered well.

 

On the other hand FLAC already will compress wide bandwidth formats somewhat better due to the same reason. Redundancy of zero bits above 20 khz. 96 khz files with only low level signal in the ultrasonic region will compress to about 40% with FLAC. If you were to put a 30 khz filter on it before compressing to FLAC it will do just a bit better than that. And nothing says you couldn't use one of the more advanced apodizing filters like MQA does. FLAC still would probably run 60% larger in file sizes. Which isn't nothing by any means, but also isn't incredibly ridiculous with network speeds available and increasing all the time.

 

So MQA is proprietary while FLAC isn't and MQA claims superior potential sound quality.

 

The biggest advantage of FLAC is that it's truly lossless, already widely adopted, and no special DACs are required (one may use a DAC with an apodizing filter, closed-form filter, a NOS DAC, etc).

[Hiro]

I would say more likely to be due to good recording and mastering rather than any particular process. At least I would like to compare a true native non-MQA 192/24 content to MQA-content to hear and see how it changes. I would rather have those new recordings in 192/24, DXD or DSD128/DSD256 rather than having it transformed through low-rate PCM while trying to fix fundamental problems of low-rate PCM.

 

I'm afraid that all MQA will lead to is mass upsampling of 16/44 sources and streaming of such as 24/96 or 24/192... As for the native 24/192 content, well, if you already have an apodizing filter in your software player or the filter is in-built in your DAC, then I don't see a compelling reason to download a lossy MQA file instead of a WAV file or FLAC.

[Hiro]

I know and have those files. So I still don't understand where you need MQA. They have the MQA files here:

https://shop.klicktrack.com/2l/468051?

 

Now tell me why there's no non-MQA hires (already decoded) download available there to compare? MQA version is remastered and upsampled version of the original:

Recorded in 44.1kHz/16bit by Lindberg Lyd, Norway, May 1993

 

So, it's all about upsampling rbcd content and offering it as "Hi-Res" after all. Just as I predicted/feared... I can't understand why some folks are so hyped by this lossy, upsampled, proprietary format.

[Hiro]

So they could decode it before streaming and delivery and deliver just ordinary standard FLAC, nothing of MQA needed at playback side.

 

If they did so, they couldn't sell all those new "MQA-ready" devices......

[Hiro]

I did some analysis and the result is quite a bit less than 16-bit worth. While the source FLAC file is pretty big. Here's some of my initial results:

 

Some analysis and comparison of MQA encoded FLAC vs normal optimized hires FLAC - Blogs - Computer Audiophile

 

In short, my result was that if you optimize the encoding to a standard FLAC (without MQA), the file is smaller than the MQA encoded one...

 

Very informative. Thanks for sharing this information.

[Hiro]

In addition to Miska's spectrograms here are the waveforms of MQA-encoded 24/44 sample from 2L & my home-made downrezzed/downsampled to 16/44 version of the 24/352 DXD master (which utilizes SoX95 linear-phase re-sampling & moderate noise-shaped MDA VST dithering):

 

- MQA:

 

- 16/44:

 

These two graphs are also very revealing. Thanks for sharing.

[Hiro]

...Meridian claims that for first, audio is encoded to MQA at A/D stage. Then, obviously, we need to edit that captured audio in studio. All editors works with PCM, so for editing we need to decode first, then edit and mix, after that re-encoding again to MQA for streaming, and after transmission/delivery and decoding from MQA to some form of PCM, listeners pop-up and says - this file sounds better! Better of what? Better than original? Better than PCM?

 

Good question

 

I also wonder whether all music will be re-done again using this multi-stage upsampling and downsampling procedure. Since many audio plugins and digital synthesizer introduce their own ringing, will MQA-encoding be applied every time such a plugin or digital synth is used?

[Hiro]

As usual Archimago chimed in: Archimago's Musings: MEASUREMENTS: MQA (Master Quality Authenticated) Observations and The Big Picture...

Not so good conclusion for this yet another format!

 

"We have a sample here (Carl Nielsen piano composition recording) which supposedly originated in 16/44 according to the description, and is now encoded in MQA as a 24/44 file. Indeed, in MQA it got bigger. No surprise since MQA is supposed to only provide bitrate reduction for high-res recordings/streams."

 

Wait, so after all this pro-MQA talk about reducing bandwidth it now turns out that the MQA file got bigger? Since 99% of PCM recordings are still only available at 16/44 resolution, this means that in most cases MQA streaming will require more bandwidth, not less.

 

This whole concept of adding additional bits and/or upsampling the audio before streaming it seemed wrongheaded to me from the start.

[Hiro]

In the mid tier, a product like the Schiit multibit DAC is by design a PCM device. The Berkeley Alpha doesn't support DSD either, I suppose it's a choice - I don't think that DAC is multibit.

 

I'm not aware of many high end DACs (ie > 10k) that do not support DSD... MSB, dcs, EmmLabs, Playback Designs all support DSD.

 

There are already more than 400 different DACs supporting DSD.

https://docs.google.com/spreadsheets/d/1GPtrINDXXFW9Nm7A7YJ6Jsiu54hKXD7vUmrAbtwrSG0/edit?pref=2&pli=1#gid=0

 

How many DACs are there with MQA? Two?

[Hiro]

I have also Metrum Musette which is discrete R2R (no DAC chips), it can take in 352.8/384k PCM, so a good target for software upsampling... Naturally it cannot deal with DSD because it is one of the rare PCM DACs.

 

R2R PCM DACs are rare, but R2R/flash PCM ADCs are rarer still. Which means that even on the R2R PCM DACs what people listen to most of the time are delta sigma recordings (downsampled and decimated to PCM with on-board ADC filters). But that part of the story is rarely mentioned in R2R DACs' marketing materials

[Hiro]

And the initial question was simply why certain manufacturers were holding out on DSD compatibility.

 

We could also ask why certain manufacturers are holding out on class D amplifiers, while others are embracing the technology. Or why certain manufacturers are holding out on tube amplifiers, while others firmly believe they deliver the best sound, etc. etc.

[Hiro]

I'm not aware of any non-SDM audio ADC on the market at the moment. Is there any?

 

AFAIK all studio ADCs that are currently in production are SDM-based.