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MQA is Vaporware

Rt66indierock

By Rt66indierock
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Ralf11

Ralf11

Posted
Posted

Here is part of it - for posterity:

 

My new article series on MQA.

Discussion in 'Audio Hardware' started by LeeS, Jan 9, 2018.

  1. Archimago

    ArchimagoWell-Known Member

    ricko01 said: ↑
    Call me a groupie if you want but I trust your opinion over others (or in the case of this thread "other" as in the singular) cause in fact your opinions arent opinions but observations backed with hard data.

    Cool... so my setup wont preclude a valid test and I already have identified albums that I have listened to 100's of times that I own on vinyl/cd/hi-res dvd-a and are also available on Tidal at CD and MQA quality.

    Of course the sticking point with any of these compares is that there are literally decades between the various releases from the original vinyl onwards so any remasterings need to be accounted for before I let the juice run down my leg after hearing MQA (noting the historical reference is via Robert Johnson and not the more derivative LZ one)

    Peter
    Click to expand...
    Great that you have the tunes ready to rock n' roll, Peter. Absolutely try to make sure you're comparing the same mastering. Would be interested to hear of your impressions and what music/gear you end up using.

    Oh yeah... No matter what, don't squeeze too hard, your family/friends might not be impressed :yikes:.

    Cheers!
     
    Archimago's Musings - A 'more objective' audiophile blog.
     
  2. Mel Harris

    Mel HarrisWell-Known Member

    Location:
    Petaluma, CA
    LeeS said: ↑
    Hansen really disgraced himself with some very personal attacks on Stuart. Friends say he was in a great deal of pain near the end of his life but still. Several prominent audio leaders have expressed to me that they lost a good bit of respect for the man.
    I think there's a certain camp in audiophilia that wants to vilify Hansen for standing up for consumers. Regardless of how many "prominent audio leaders" (sheesh :rolleyes:) allegedly lost respect, his stand against MQA makes him a bona fide hero to many!
     
    Last edited: Today at 3:34 PM
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  3. Agitater

    AgitaterForum Resident

    Location:
    Toronto
    Merrick said: ↑
    Well, Tidal is by all accounts on the verge of bankruptcy and Qobuz did in fact declare bankruptcy once before, so I wouldn’t say what they’re doing is exactly working. I’m pretty sure Jay-Z assumed some bigger entity would have bought Tidal by now like Apple did for Beats. Also whatever money they do have sure isn’t being spent on UI or discovery algorithms, and I suspect if any of the bigger services offered lossless for even $5 less per month than Tidal, subscribers will be scrambling to switch subscriptions.
    Depending on which publications you read, TIDAL will either be out of business before the end of 2018 or in the black in early 2019 (or have I got the years reversed?). 

    I’m suggesting that TIDAL and Qobuz know exactly what sort of business they’re in and have picked their respective minimum target market types and sizes needed to achieve profitability, and have geared up to hit and then exceed those targets in the time frame in which it all has to be done before core investors jump ship and tank both companies. Time will tell, and not much more time at that. Personally, as a TIDAL HiFi subscriber I’m rooting for both companies to succeed. 
     
    Merrick said: ↑
    Qobuz entering the US market will be an interesting thing. Their business model is a bit different in that you pay upfront annually for unlimited hi-res streaming but also discounts on hi-res purchases. You can pay monthly for 16/44 lossless or lossy streaming. If they were smart, they’d price their 16/44 tier lower than Tidal’s, and dangle free upgrades to the hi-res service for a month to get people hooked. I’m curious to see what they chose to do.
    Me too, especially if Qobuz hits Canada at the same time as it hits the U.S. market. As for dangling a lower price than TIDAL for its 16/44 stream, I have the sinking feeling that’s an approach that might never succeed, because in this market there’s a high probability that it could result in a race to the bottom. Both companies would still die, but one would die with a larger subscriber base. Lower subscriptions rates, at this point, I think just means a faster cash burn rate for the companies and a consequentially rapid cash flow crunch where they have to go back to VC’s for another round and to existing investors for yet another cash call. 

    I listen to an average of eight new albums - ones I’ve never heard before and that I’ve never owned in any format previously - every month on TIDAL HiFi, all at 16/44.1 at between 850-1411 kbps FLAC. At $20 a month, I’m getting more than my money’s worth. If TIDAL decides to raise its HiFi subscription to $25 or $30/month, I’ll pay it.

    I also listen to JazzFM 91.1 FM radio in Toronto. It’s a non-profit, it’s superb, its signal is astonishingly good, and because it’s a non-profit there are a bare minimum of commercials. The station runs quarterly on-air fund raising campaigns. I contribute $20 a month to Jazz FM as well because I love the station and because I love the whole feeling that they’re curating jazz across a couple of dozen different programs and hosts just for me. Of course, that’s one of the great attractions of a great radio station. Anyway, again, I’m personally not looking for the lowest price but rather the best possible quality at what I consider to be a sensibly profitable price for the company providing the music to me. If Jazz FM pleads for a bump, I’ll raise my monthly contribution to $30. Well worth it. I’m happy that I can afford it. 

    I hope TIDAL and Qobuz make it.
     
     
  4. Merrick

    MerrickForum Resident

    Location:
    Portland
    Agitater said: ↑
    Depending on which publications you read, TIDAL will either be out of business before the end of 2018 or in the black in early 2019 (or have I got the years reversed?).

    I’m suggesting that TIDAL and Qobuz know exactly what sort of business they’re in and have picked their respective minimum target market types and sizes needed to achieve profitability, and have geared up to hit and then exceed those targets in the time frame in which it all has to be done before core investors jump ship and tank both companies. Time will tell, and not much more time at that. Personally, as a TIDAL HiFi subscriber I’m rooting for both companies to succeed.



    Me too, especially if Qobuz hits Canada at the same time as it hits the U.S. market. As for dangling a lower price than TIDAL for its 16/44 stream, I have the sinking feeling that’s an approach that might never succeed, because in this market there’s a high probability that it could result in a race to the bottom. Both companies would still die, but one would die with a larger subscriber base. Lower subscriptions rates, at this point, I think just means a faster cash burn rate for the companies and a consequentially rapid cash flow crunch where they have to go back to VC’s for another round and to existing investors for yet another cash call. 

    I listen to an average of eight new albums - ones I’ve never heard before and that I’ve never owned in any format previously - every month on TIDAL HiFi, all at 16/44.1 at between 850-1411 kbps FLAC. At $20 a month, I’m getting more than my money’s worth. If TIDAL decides to raise its HiFi subscription to $25 or $30/month, I’ll pay it.

    I also listen to JazzFM 91.1 FM radio in Toronto. It’s a non-profit, it’s superb, its signal is astonishingly good, and because it’s a non-profit there are a bare minimum of commercials. The station runs quarterly on-air fund raising campaigns. I contribute $20 a month to Jazz FM as well because I love the station and because I love the whole feeling that they’re curating jazz across a couple of dozen different programs and hosts just for me. Of course, that’s one of the great attractions of a great radio station. Anyway, again, I’m personally not looking for the lowest price but rather the best possible quality at what I consider to be a sensibly profitable price for the company providing the music to me. If Jazz FM pleads for a bump, I’ll raise my monthly contribution to $30. Well worth it. I’m happy that I can afford it.

    I hope TIDAL and Qobuz make it.
    Click to expand...
    Sounds like you and I use streaming differently. I use streaming to hear an album once or twice and see if it’s worth owning, and then for in the car listening so I don’t have to try and fit my whole library on my phone or keep a DAP in my car. Neither of those use cases requires that I pay a lot of money for the highest quality sound possible. And I suspect my use case is more common than those who use streaming for continuous critical listening.
     
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  5. Bubbamike

    BubbamikeForum Resident

    Back in the early days of the Gramophone they did demonstrations, they would have a singer behind a curtain and a Gramophone behind an adjoining curtain. The audience would then sit and the singer would sing and they would switch to the Gramophone and apparently no one could tell the difference between them. They were just alike. Or so the tests claimed. 

    So Bob Stuart is running the same dog and pony show as they did at the turn of the last century. Barnum was totally correct.
     
     
  6. Agitater

    AgitaterForum Resident

    Location:
    Toronto
    LeeS said: ↑
    Hansen really disgraced himself with some very personal attacks on Stuart. Friends say he was in a great deal of pain near the end of his life but still. Several prominent audio leaders have expressed to me that they lost a good bit of respect for the man.
    However incautious Charles Hansen’s comments may have been, he wasn’t wrong. Implying that Hansen’s criticism doesn’t count because it was rude is inappropriate. Hansen was right to speak out, and he spoke truthfully and accurately on several occasions on the matter. 

    Consider too, that when one engineering peer calls out another he does a service to all other peers in engineering by pointing out flaws, faults and misrepresentations in a paper that was not properly peer reviewed before publication. That’s a critical error on the part of JAES and it’s shame that Stuart submitted the paper in the shape it was in. Several other engineers came out in direct support of Hansen’s critique even if they didn’t agree with the Hansen’s tone. 

    Confrontation is frequently painful, moreso when a person is confronted for his obfuscations and moreso when a company or organization is taken to task for its misrepresentations. I am unsympathetic. They bring such difficulties on themselves.
     
  7. Merrick

    MerrickForum Resident

    Location:
    Portland
    I would argue that Stuart’s craven cash grab in the form of MQA is far, far more disgraceful than Hansen’s rebuke of it.
     
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  8. Agitater

    AgitaterForum Resident

    Location:
    Toronto
    Merrick said: ↑
    Sounds like you and I use streaming differently. I use streaming to hear an album once or twice and see if it’s worth owning, and then for in the car listening so I don’t have to try and fit my whole library on my phone or keep a DAP in my car. Neither of those use cases requires that I pay a lot of money for the highest quality sound possible. And I suspect my use case is more common than those who use streaming for continuous critical listening.
    I agree and I’d bet real money that your use case is more common than mine, without a doubt. Just as uncommonly, I don’t use a DAP of any kind. The only things I stream in the car (from my iPhone 7s) are podcasts, all spoken word such as In Our Time from BBC 4, Skeptics Guide to the Universe from the SGU based in New England, and a couple of others. The only music I listen to in the car comes through FM radio including the aforementioned Jazz FM 91.1 and Classical FM 96.3 (another excellent, albeit more commercial, FM station in Toronto). 

    Friends and I regularly curate and assemble TIDAL HiFi playlists that we share in advance of Scotch & Jazz listening sessions. We go through LP binges too, but TIDAL HiFi predominated in 2016 and 2017. Superb service. 

    All that said, every so often I too come across something on TIDAL that sets me on a search to find either the LP or the CD. Finding a new copy or a good used copy in either format is relatively easy in Toronto because we’re lousy with music stores in the city. From Grigorian Music for a massive classical selection (and a very respectable jazz selection), to Cosmos West for a massive used jazz LP selection, to Tonality for a comprehensive selection of new age, electronica and you-name-it that-is-current and cutting-edge, to Sonic Boom with its huge inventory of new and used pop, rock of all kinds, indie and everything else, to June Records, Soundscape, Play Da Record, the very excellent Rotate This, and the European-connected Quixotic Records where I get all the great jazz and avant-garde releases from Europe that never otherwise make it over here, and a dozen more music stores that I don’t regularly visit, the search can be a real blast. Toronto is great for LPs and CDs, no question about it. I’m lucky to have this sort of access.
     
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  9. Rt66indierock

    Rt66indierockNew Member

    Location:
    Scottsdale Arizona
    Charley Hansen was a friend. Any audio leader that lost respect for him in 2017 is support for why we need new audio leaders.
     
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  10. LeeS

    LeeSRoll Tape!Thread Starter

    Location:
    Atlanta
    Rt66indierock said: ↑
    Charley Hansen was a friend. Any audio leader that lost respect for him in 2017 is support for why we need new audio leaders.
    If Charlie had good arguments, he could present them without personal attacks.
     
    Contributor, Part-Time Audiophile
     
  11. rbbert

    rbbertForum Resident

    Location:
    Reno, NV, USA
    LeeS said: ↑
    If Charlie had good arguments, he could present them without personal attacks.
    Maybe he was frustrated at metaphorically beating his head against a wall (MQA and Stuart’s supporters) and in unreasonable physical pain. The combination could cause anyone to lash out; it doesn’t mean he was wrong.
     
     
  12. Rt66indierock

    Rt66indierockNew Member

    Location:
    Scottsdale Arizona
    New
    LeeS said: ↑
    If Charlie had good arguments, he could present them without personal attacks.
    Charley had good arguments in 2014. Nobody listened in 2015 and 2016 so he turned up the volume until people did. In any case I was in the room when Bob Stuart was called a liar at the Los Angeles Audio Show and talked with him afterward. As opponents of MQA have found since then personal attacks are effective. MQA had no presence at RMAF 2017 for example.
     
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  13. Archimago

    ArchimagoWell-Known Member

    New
    LeeS said: ↑
    If Charlie had good arguments, he could present them without personal attacks.
    I don't think the majority of us want to get personal. But there are times when it's perhaps warranted, maybe even necessary to go beyond usual etiquette and political correctness. Avoidance of conflict is just as damaging in the long run in many situations in life when cowardice leads to stagnation.

    For Mr. Hansen, in retrospect, perhaps there was recognition that time was short and things needed to be said.

    Remember that his comments were not just about MQA. He had concerns about the broader context of audiophilia and the media systems built around the hobby; how it was being reported, marketed, and by whom. About an industry that he spent much of his life helping to build...

    Full disclosure: I don't agree with Charlie on everything he said... In fact, I've told him that I didn't like his digital filtering in the PonoPlayer and everything was still cool! :)
     
    Archimago's Musings - A 'more objective' audiophile blog.
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  14. soundQman

    soundQmanIdealist of the Musical Apocalypse

    Location:
    Arlington, VA, USA
    New
    Archimago said: ↑
    Remember that his comments were not just about MQA. He had concerns about the broader context of audiophilia and the media systems built around the hobby; how it was being reported, marketed, and by whom. About an industry that he spent much of his life helping to build...
    This reminds me of how bitter J. Gordon Holt became toward the end of his life. In interviews I read he had completely despaired of what he thought the hi-fidelity audio industry had become. He regarded it as a total betrayal of what he had envisioned, and had labored for so many years to establish. He essentially thought that his life's work had come to naught. I'm not sure he had an objective or an unchanging view of things throughout, but one thing he did lament near the end was the audio magazines' (including his own, Stereophile) rejection of blind listening tests as a reviewing method. I know he was also profoundly disappointed at the relative lack of attention to and acceptance of properly implemented multi-channel systems.
     
    Last edited: Today at 5:19 PM
    "Do not go gentle into that good night.
    Rage, rage against the dying of the light." - Dylan Thomas
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  15. ricko01

    ricko01Member

    Location:
    New Zealand
    New
    LeeS said: ↑
    Hansen really disgraced himself with some very personal attacks on Stuart. Friends say he was in a great deal of pain near the end of his life but still. Several prominent audio leaders have expressed to me that they lost a good bit of respect for the man.
    Your an egotistical little bugger arent you... like to drop "names" here and there.

    I would suggest that you made more of a disgrace of yourself with this comment... the guy is dead for crying out loud.

    But when he was alive he was a straight shooting, extremely well liked and successful audio engineer.... I have never seen anyone bitch about his products being voodoo.

    He would be one of a handful of people that would be in the best position to judge MQA and he has my respect for calling it the way he saw it and along with a group of other manufactures made a public statement about how they wouldnt contaminate their product lines with MQA.

    He didnt attack Bob.... he attacked MQA .

    Peter
     
  16. tmtomh

    tmtomhForum Resident

    New
    LeeS said: ↑
    Hansen really disgraced himself with some very personal attacks on Stuart. Friends say he was in a great deal of pain near the end of his life but still. Several prominent audio leaders have expressed to me that they lost a good bit of respect for the man.
    While I disagree with @LeeS vigorously on many things in this long thread, I've repeatedly tried to avoid the more overheated rhetoric and attacks that some of his other critics have employed.

    In regard to this particular comment of his quoted above, though, I have to say I think that folks have gone far to easy on Lee. In my view this is an appalling comment. There's the repulsive cowardice of asserting (not opining, but flat-out asserting) that a dead man who can't defend himself "disgraced himself" at the end of his life. Add to that the incredibly condescending, and boundary-violating, claim that the man was in a lot of pain and so maybe that's why he lost his mind with those "disgraceful" comments. And then the finish: invoking countless unnamed "prominent audio leaders" to further damn the man with what is tantamount to gossip.

    I don't care how apparently civil your tone might seem, Lee. That's disgusting. You should be ashamed.

    (Edit: I see @ricko01 /Peter and I were typing similar thoughts at the same time. :righton:)
     
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  17. soundQman

    soundQmanIdealist of the Musical Apocalypse

    Location:
    Arlington, VA, USA
    New
    Apparently the pronouncements and sentiments from "industry leaders" as well those from MQA personnel and promoters function for Lee like that little blue light that he thinks is supposed to assure customers of "authentication" and inspire trust.
     
    "Do not go gentle into that good night.
    Rage, rage against the dying of the light." - Dylan Thomas
     
  18. Merrick

    MerrickForum Resident

    Location:
    Portland
    New
    LeeS said: ↑
    If Charlie had good arguments, he could present them without personal attacks.
    Actually the two things are not related. Hansen's arguments were solid, and additionally he also was blunt in his delivery. It's very convenient for you to attack his character instead of discussing the content of his arguments.
     
     
  19. Rt66indierock

    Rt66indierockNew Member

    Location:
    Scottsdale Arizona
    New
    rbbert said: ↑
    Maybe he was frustrated at metaphorically beating his head against a wall (MQA and Stuart’s supporters) and in unreasonable physical pain. The combination could cause anyone to lash out; it doesn’t mean he was wrong.
    Many people were frustrated by the press reaction to MQA in 2014, 2015 and 2016. Charley was no exception. He talked with me a couple of times about how I got people to listen with the Vaporware thread. But generally I got brain dump on digital audio when we talked in 2017.
     
     
  20. New
    Agitater said: ↑
    You wrote Auralic Aries in your post, not Auralic Aries Mini. So I was speaking to what I know. I own the Aries; you own the Aries Mini. One contains a DAC; the other does not. Sorry - I can only respond to what someone writes, not what I think they might have meant to write.
    Puh-leez! I’ve written that I have an Aries Mini many times. The rest of your post about the Aries (any Aries with the new firmware) not being able to do MQA was completely wrong as well. Just admit you were wrong and move on. Too many snowflakes on this forum! :laugh:
     

    Eric
    Ad lib to fade . . .
     
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rickca

rickca

Posted
Posted

I suppose Lee figures everyone will now want to read his future articles.  That's one of the reasons he sticks around.

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firedog

firedog

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Posted

1. Pretty amazing Hoffman deleted the thread. I'd assume it was because MQA was getting killed there. Now I remember why I hadn't participated much in discussions there for years. He could have just closed it and left it there, but he deleted it. Who got to him?

 

2. As far as Charlie Hansen's critique of ML's MQA review: I found it telling that ML's main example was "Riders on the Storm" and how it sounded 

Quote

I'd never heard Jim Morrison's voice sound the way it does through the MQA version, which can be described as being more dimensional, and pleasantly softer in the mix compared to any other digital version I've heard.

 

Charlie pointed out that the 17bit MQA version was actually missing some of the detail in the vocal expression, which took away from what the vocal was communicating.  Just another example of how "pleasant" and "soft" gets pushed to as as superior SQ,
 

Main listening (small home office):

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FredericV

FredericV

Posted
Posted
1 hour ago, firedog said:

Charlie pointed out that the 17bit MQA version was actually missing some of the detail in the vocal expression, which took away from what the vocal was communicating.  Just another example of how "pleasant" and "soft" gets pushed to as as superior SQ,

 

Last year I bought a Mytek Brooklyn to replace my old Auralic Vega (which was my backup DAC - main DAC is Metrum Adagio), and compared the DXD and MQA files from 2L.no on the mytek.

MQA actually changes the voice, there's a raw quality in the voice that is gone, that has been polished. The DXD is much more realistic, and the MQA version sounds like someone played with a reverb effect.

Now that we understand the artefacts of minimum phase filters, and it's version with one cycle postringing as implemented by MQA, these effects can be reproduced outside MQA.

I believed for a while minimum phase was a solution to kill pre-ringing, but as it changes the phase for which the phase shift is frequency dependent, it also changes depth/width/stage. It feels like something is being cut off. Bass gets tighter, up to a level where there's less  body.

The best part is that those researching MQA and it's filters, came to an even better filter config than what MQA is offering:

http://archimago.blogspot.be/2018/01/musings-more-fun-with-digital-filters.html


The intermediate phase filter as proposed by Archimago does not suffer from the artefacts which MQA suffers from, including severe aliasing and phase errors.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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adamdea

adamdea

Posted
Posted
1 hour ago, FredericV said:


The best part is that those researching MQA and it's filters, came to an even better filter config than what MQA is offering:

http://archimago.blogspot.be/2018/01/musings-more-fun-with-digital-filters.html


The intermediate phase filter as proposed by Archimago does not suffer from the artefacts which MQA suffers from, including severe aliasing and phase errors.

Whilst I remain unpersuaded that there is any sound case for anything other than linear phase., I welcome Archi's work as ever. It's interesting isn't it that the cheerleaders for minimum phase (ie the same publications as now cheer-lead for MQA) did not in all their researches point out the time domain problems of minimum phase. 

You are not a sound quality measurement device

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manisandher

manisandher

Posted
Posted
1 hour ago, FredericV said:

The best part is that those researching MQA and it's filters, came to an even better filter config than what MQA is offering:

http://archimago.blogspot.be/2018/01/musings-more-fun-with-digital-filters.html


The intermediate phase filter as proposed by Archimago does not suffer from the artefacts which MQA suffers from, including severe aliasing and phase errors.

 

 

Maybe I'm really dense, but I'm find this confusing. Aliasing occurs during analogue-to-digital conversion, and not during digital-to-analogue conversion, and yet he talks about using an anti-alias filter in a DAC. Are the terms 'aliasing' and 'imaging' really so interchangeable?

 

Happy to be put right.

 

Mani.

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adamdea

adamdea

Posted
Posted
5 minutes ago, manisandher said:

 

 

Maybe I'm really dense, but I'm find this confusing. Aliasing occurs during analogue-to-digital conversion, and not during digital-to-analogue conversion, and yet he talks about using an anti-alias filter in a DAC. Are the terms 'aliasing' and 'imaging' really so interchangeable?

 

Happy to be put right.

 

Mani.

Spot on. The "aliasing region" graph suggests that he must be talking about A/D or downsampling.

You are not a sound quality measurement device

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mansr

mansr

Posted
Posted
1 hour ago, manisandher said:

Maybe I'm really dense, but I'm find this confusing. Aliasing occurs during analogue-to-digital conversion, and not during digital-to-analogue conversion, and yet he talks about using an anti-alias filter in a DAC. Are the terms 'aliasing' and 'imaging' really so interchangeable?

A lot of people, especially non-experts, seem to mistakenly use the term aliasing when they really should be saying imaging.

 

1 hour ago, adamdea said:

Spot on. The "aliasing region" graph suggests that he must be talking about A/D or downsampling.

Yes, that graph doesn't make sense in the context.

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Fokus

Fokus

Posted
Posted
1 hour ago, manisandher said:

Aliasing occurs during analogue-to-digital conversion, and not during digital-to-analogue conversion, and yet he talks about using an anti-alias filter in a DAC. Are the terms 'aliasing' and 'imaging' really so interchangeable?

 

They are not interchangeable.

 

Aliasing is an issue whenever the sampling rate is reduced, with as limit case the A-to-D sampling act.

 

Imaging is an issue whenever the sampling rate is increased, with as limit case the D-to-A conversion act.

 

Aliasing destroys information, because unintended signal is forced to occupy the same space as the payload signal, making them inseperable.

 

Imaging replicates information, because the images are copies of the payload signal.

 

This said, it is a sad fact that in textbooks and courses 'aliasing' has been erroneously in use for both phenomena.

 

 

Thankfully I was introduced to signal processing by an old war horse (literally, he was also a colonel in the reserves) who kept strict discipline, in particular pertaining to the proper use of aliasing/imaging and the correct pronounciation of finite/infinite.

 

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Shadders

Shadders

Posted
Posted
15 minutes ago, mansr said:

A lot of people, especially non-experts, seem to mistakenly use the term aliasing when they really should be saying imaging.

Hi,

I think you are being a bit unkind here. When the image frequencies overlap the baseband frequencies - it is called aliasing. Many books call it aliasing for the reconstructed signal image overlap issues. The books i have state a low pass filter for decimation, and use the term aliasing, but do not use the term imaging.

Maybe it is an industry thing - some parts use imaging, and others comfortable to call it aliasing.

Regards,

Shadders.

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manisandher

manisandher

Posted
Posted
47 minutes ago, Fokus said:

... and the correct pronounciation of finite/infinite.

 

 

FinIte and infinUt? Shame he didn't drill 'pronUnciation' into you too ;-)

 

Mani.

Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs

Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers

Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro

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mansr

mansr

Posted
Posted
Just now, Shadders said:

OK - i will bite. Which bit is wrong ?

Image frequencies produced when upsampling fall entirely outside the baseband. Take a signal with 48 kHz sample rate. If this is upsampled to 96 kHz by repeating samples or inserting zeros, a mirror image of the 0-24 kHz band appears at 24-48 kHz. There is no overlap. Aliasing of high frequencies onto low happens only when downsampling (or sampling a continuous-time signal).

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manisandher

manisandher

Posted
Posted
1 hour ago, Shadders said:

When the image frequencies overlap the baseband frequencies - it is called aliasing.

 

 

From Lavry's whitepaper, sampling 25 and 35Khz tones at 48KHz:

 

5a6b30cab1652_LavryAliasing.thumb.JPG.5c25d8888af6c080937f32ee5eccd154.JPG

 

Aliasing... with no "image frequencies overlapping the baseband frequencies" at all.

 

Mani.

Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs

Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers

Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro

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Shadders

Shadders

Posted
Posted
3 minutes ago, mansr said:

Image frequencies produced when upsampling fall entirely outside the baseband. Take a signal with 48 kHz sample rate. If this is upsampled to 96 kHz by repeating samples or inserting zeros, a mirror image of the 0-24 kHz band appears at 24-48 kHz. There is no overlap. Aliasing of high frequencies onto low happens only when downsampling (or sampling a continuous-time signal).

Hi mansr,

I did not state whether it was downsamplng or upsampling, just what the books say when mentioning aliasing.

Regards,

Shadders.

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Shadders

Shadders

Posted
Posted
3 minutes ago, manisandher said:

 

 

From Lavry's whitepaper, sampling 25 and 35Khz tones at 48KHz:

 

5a6b30cab1652_LavryAliasing.thumb.JPG.5c25d8888af6c080937f32ee5eccd154.JPG

 

Aliasing... with no "image frequencies overlapping the baseband frequencies" at all.

 

Mani.

Hi,

Discussion was on imaging, not your specific example.

All the books show the issue of too low sample rate used on a signal with a bandwidth higher than Fs/2. Just an example - no use of the word image, just the word alias of the image with the baseband.

Regards,

Shadders.

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manisandher

manisandher

Posted
Posted
2 minutes ago, Shadders said:

Discussion was on imaging, not your specific example.

 

Really?

 

1 hour ago, Shadders said:

When the image frequencies overlap the baseband frequencies - it is called aliasing.

 

[Highlights mine.]

 

Mani.

Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs

Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers

Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro

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