Your answer includes zero information. But it is a bit personal and I have an issue with that.
No, I donāt. And neither do you. The difference is, I shut up about it.
Look: a guy comes and claims to have made an invention that has a beneficial effect. And he says clearly that this invention is different from apodizing. Although both are related to the goal of time precision, which he has long focused on and addressed with other inventions. In the absence of more technical information and listening tests, we can have two possible reactions:
- He is a charlatan and a fraud and a liar and his invention cannot possibly work.
- Based on his track record he has a certain credibility and I will evaluate the invention, until then I will have an open mind.
Number 2 is scientific skepticism. And practical skepticism says, until I have more evidence of benefits I wonāt spend my money on it. All reasonable positions.
Number 1 is sometimes justified too, when an unknown guy makes claims that are against all scientific understanding (āput your DAC under a pyramidā). But I donāt think that is justified here.
(For the record, I have the full-fat Meridian gear and I have some albums in MQA and non-MQA form, and Iām not impressed, no stunning difference. Maybe because the recordings are stunning in any case, maybe because modern gear does a good job even with Redbook, maybe because my ears are 16 bit.)
2 Likes
16 bit ears! Thatās a great line. Iām going to plagiarize that one!
I posted >zero information above that does not fit your conclusions about MQA and you just seem to ignore it.
For example
MQA operating at 44.1 kHz has lower temporal blur than todayās ānormalā 192 kHz. (Read that sentence again and think what it means).
If you are interested in learning more then this should prompt sensible discussion.
You can of course maintain again that this is just marketing ā ā , PR baloney or whatever. However, if you ask the designer of the technology for an answer and then just dismiss it or ignore it then it hardly helps the discussion.
Afaik ā¦ The CA FAQ on MQA with Bob Stuart ( whose words I quoted above) should be up sometime soon. Hopefully that will provide some much needed clarity.
Firstly, I only referred to MQA and itās claims - yes I found many of them dubious or more precisely overhyped - but I would like for someone to provide real information rather than repeating MQAās unsubstantiated claims.
Secondly, I look forward to Bob Stuartās answers to the questions posed on CA.
Thirdly, if you have a problem with my arguments please refute them. I think your replies really do get personal and I am particularly puzzled that you are a moderator. What gives?
1 Like
Just a note about nomenclature. Apodising has accrued a limited technical meaning in audio circles associated with filters that reduce ringing or pre-ringing, but it is a broader term than that. It was first used to describe techniques in astronomy and optics to āremove the footā, meaning unwanted artifacts, by signal processing and itās general meaning is to change the shape of a mathmatical function. Time deblurring in MQA is apodising in the general sense, whether or not it does anything about ringing or pre-ringing.
Since when shrink something in time domain, it expands in frequency domain. So of course ultimately you get optimal time domain response with Dirac pulse - one tap with coefficient of 1 so every sample is multiplied with 1. Of course that doesnāt filter anything at all so it is called all-pass filter. And for optimal frequency domain response the filter would have infinite number of taps which means that nothing would ever come out of it, because the delay would be also infinite and the time domain ringing would be infinitely long. Of course thereās infinite number of possibilities between the two extremesā¦ 
But roughly width of the transition band defines time domain resolution and vice versa. MQA has seemingly chosen to spend the entire 20 - 40 kHz band for filter transition. So roll-off begins at about 20 kHz and ends at 40 kHz. With result sampled at 88.2 or 96 kHz depending sample rate family. So entire octave is spent for the sake of apodization at the cost of preserving true transient high frequency components that define the wave shape. So instead of having ringing, the transient rise just becomes slow.
However, if the transient never reached transition band of the original filter, there is no ringing in first place, so lot of pure HF content is traded for nothing. No added advantage.
Apodizing filters can be linear or minimum phase or anything between. There is no frequency impact at all between the two, only difference is phase response. The amount of ringing/frequency response is up to designerās emphasis in on the various properties. I personally prefer to stand right in the middle between frequency and time domain performance trying to optimize both simultaneously, while providing options for either extreme too. One person is just more sensitive to one type of thing while other is sensitive to other type.
For that reason Iāve been recommending choice of linear vs minimum phase depending on source content genre (thus recoding technique).
If you want to get rid of thinking about the problem in first place, look at hires content. Preferably DSD, DXD or at least 192/24. Then you donāt need to worry about filter ringing or transient resolution. You can then focus purely on the modulator and analog performance.
Which, in itself, is not a new thing. It has been around in audio for 10+ years alreadyā¦
Also converter response compensation has been around for long time, some ADC and DAC chips do that, while otherās just donāt need it.
Thatās why people are looking into things that could possibly be something new.
I do that straight in the software player, no need for HT processor or other hardware.
Hmmh, I just see something contradictory here. I can run tracks through apodizing filters and store those as WAV/FLAC. Those are āpre-apodizedā and de-blurred then. End of story, nothing to call home about. But I donāt bother spending disk space for that so I do it on the fly instead.
I played same track through same MQA capable DAC and recorded the output from analog outputs of the DAC using Focusrite Forte running at 192/24.
In the following results, lines at 33 and 66 kHz are from the SMPS of the Forte. Increasing noise floor slope at the top is left-over from PCM conversion of the ADCās delta-sigma modulator running at 6.1 MHz.
First I played the DXD master on-the-fly converted to 192/16 using TPDF dither which consumes about the same bandwidth as the MQA encoded one. This has clean HF content up to about 56 kHz.
Then I played MQA encoded version (with MQA light on the DAC indicating decoding). Now HF content runs out at 30 kHz, then thereās a wide gap and alias images from leaky upsampling filter visible between 60 and 88 kHz. (thus MQA content is sampled at 88.2 kHz and then upsampled through leaky filter to 176.4 kHz)
There is also enough increase in noise floor that the SMPS harmonics almost disappear in the noise.
1 Like
[quote=ājussi_laako, post:269, topic:8204ā]
I do that straight in the software player, no need for HT processor or other hardware.
[/quote] You are not suggesting that your software works without a computer?
Iām not comparing technologies, Iām just making the point that time alignment is a known issue that is commonly addressed, not just about frequency. As is quite clear from my text.
[quote=ājussi_laako, post:269, topic:8204ā]
Hmmh, I just see something contradictory here. I can run tracks through apodizing filters and store those as WAV/FLAC. Those are āpre-apodizedā and de-blurred then. End of story, nothing to call home about. But I donāt bother spending disk space for that so I do it on the fly instead.
[/quote]Of course. So do Ayre and Light Harmonic and Meridian. MQA does not say they are about apodizing, they just mention it as a side benefit if you listen without a decoder. Again, I wasnāt promoting that approach, I was just showing that according to MQA description the process is distinct from apodizing. As is clear from my text.
Jussi, I donāt understand why you are doing this storm of MQA attacks.
āJussi is really smart and HQPlayer is great?ā Good luck to you, but the MQA thread of the Roon forum doesnāt seem like the right venue.
āMQA is a crock and is going to fail?ā Maybe, but why do you care?
āI want to make sure MQA fails for some reason?ā Why? Doesnāt seems like a threat, it will succeed or fail in the fullness of time.
āTrying to save the Roon community from wasting their money on MQA gear?ā I donāt see anybody rushing to do that.
Why?
1 Like
I value Jussiās contribution to the post. He is attempting to provide unemotional data behind MQAās self proclaimed ārevolutionaryā technology. I find it a refreshing counterbalance to blind cheerleading.
2 Likes
I see another problem for MQA adoption, even if it works and achieves its goals, and even if you have an MQA-enlightened system in your music room.
I do, but I also have other high end gear in other rooms, and a nice A&K mobile for travel, and a good system in my car. Some people have vacation homes, or an office system. And those other systems are not MQA enlightened.
If we accept, for the purpose of this discussion, the claim that MQA is better than 192 or DSD when decoded, and when not decided it is better that Redbook but not as good as 192 or DSD, what should I buy? If I buy MQA content the music room is great but the other locations are not. If I buy high res, all of them are plenty good.
Not going to buy double content. MQA seems like a questionable trade off, unless I consider the music room ātempleā to be supremely important.
This situation will prevail until all my systems are MQA enlightened. Seems like an adoption blocker.
It is interesting to note from the HQPlayer thread that Jussi is 100% loaded up for the next year but clearly is clearly able to spend a lot of time and effort in throwing rocks at MQA.
I quote āAre you would be sure Roon is ready to spend the time and effort needed? I would need some true assurances before I begin doing something outside of my existing plans which is already much more than 100% of my available time for a coming year at least. Iāve been hit couple of times in past where companies want to do something with me, and me spending lot of time and effort on something that ends up in a dead end. Thatās loss of my precious time I cannot get back.ā
I know many of you have great respect for Jussi but statements like this one below loose him all credibility with me.
āSo only reason I can see for having the codec hassle is to be able to collect money from both ends of the chainā
Really Bob Stuart an industry veteran with many digital audio achievements over the last 25 years is just a huckster trying to con both the industry and the consumer out of money?
Makes me wonder why Jussi is spending so much effort on this when he so busy for the next year. Could it be that MQA (along with other things) does upsampling in the decoder so if MQA really does take off people will not need the main feature of HQPlayer anymore.
Or possibly (without any interest in the discussion) he works a standard 8 to 10 hour day like most people and is doing this in his spare time in exactly the way I assume you are.
Could be but in that case interesting that he chooses to spend his spare time on something so closely work related.
The amount of marketing hyperbole just sparked my interest to find out things behind it and itās technical performance.
It is quality threat for me personally, if for example Tidal would decide to switch over their HiFi stream to MQA encoded then the quality would have negative impact. I fail to see any advantage of MQA without decoder. If Tidal wants to stream hires, IMO, it should be done in open fully FLAC compatible way. If they keep streaming RedBook quality, it is best kept as it has been without messing up the data to become several times larger with reduced quality.
It is also about DRM in SACD-sense. That without DRM you get reduced quality ācompatibilityā version and with DRM you can get full āqualityā. And I hate DRM for the reasons I explained before (once something goes out of fashion it becomes impossible to open the DRM container).
Same source brought us MLP for DVD-A. That was bad, you cannot rip those in the way you can rip RedBook to keep listening content you purchased still today. DVD-A players are rare curiosity these days and after a while the discs become junk because one cannot play those anymore. I was as much against MLP at that time as Iām against MQA now. For the same reason.
Weāre finally free from DRM for music purchases and I donāt want to see it come back. DRM creates access longevity problem to the content I have purchased.
1 Like
There is work and then there is āworkā. This is not related to workā¦
But overall, I do HQPlayer because Iām passionate about sound quality, not because I need money or something like that. Since Iām passionate about sound quality I also participate on various discussions here and at CA forum.
Iām also passionate about underwater acoustics and that kind of stuff, but this is not a forum to discuss about acoustic detection of submarines or things like thatā¦ 
I am not going to spend 24/7 on HQPlayer. Iām 100% loaded within the time allocation Iām giving to HQPlayer. In addition I am still going to eat, sleep, do other work, go sailing at summer, take vacation AND discuss here and at CA and DIY Audio forums about various stuff. Like the DSC2 DAC I mentioned.
I have list of things to be implemented in HQPlayer and my estimate for running through that list is at least a year. Iām pretty sure Roon also other things to be implemented and worked on than deeper HQPlayer - Roon integration. It doesnāt mean that we couldnāt return to that topic any day, but it just means that it is probably not the No.1 priority on either sideās TODO-list.
Why does the content need to be end-to-end protected with encryption keys? So that even someone recording the music cannot do the encoding on their own machine (without spending $25k for encryption hardware), but purchase encoding as a service from some vault? Why it is not encoded in standard FLAC that can be decoded by any standard decoder?
Thanks Jussi, agree with your comments. Remember also all the other times we have been āill treatedā by the music industry apart from MLP mentioned by Jussi:
- We almost all (?) have SACDs we cannot play through Roon due to copy protection
- We have HDCDs that sound worse than CDs unless decoded (impossible for most when streaming Tidal HDCDs)
- We have gotten ānew / remasteredā music that sound like crap due to compression (loudness war)
- We have bough / streamed Music that sounds like crap due to watermarking in the midrange (if you have missed this see for example here: http://www.mattmontag.com/music/universals-audible-watermark)
- We have bought copy protected CDs that crash our computers if we try to play them on the computer etc etc
Therefor we should be very sceptical to a new standard like MQA that have all the functions built in to make our music playing of these files very difficult and argubaly (at least from a technical standpoint) have much worse quality (compared to 192/18 Flac that is comparable in file size according to Jussi).
And by we I mean all of us who love Music and just want to listen to it when we want, how we want and in best possible quality. 