High Resolution Audio, A History and Perspective MQA included

This is an interesting read on all things digital and High Res. PDF

  1. Interesting bit , nope too technical, interesting bit, nope too technical, loop to 10.

Must look some of this up… :slightly_smiling_face:

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More reading to challenge the mind…

Now you are just playing with me.

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You want more? :joy:

Thought this thread was about high resolution then I saw contemporary mp3 included in the subject :rofl:

It’s History and perspective, MP3 certainly gives both.

I thought I’d try and figure out what pre ringing was…apparently is either an artefact of quantum mechanics or The Tardis as it involves going back in time before the sound happened. What?

I’m in the garden with the sound of birds, multiple lawnmowers and strimmers in the background listening through the headphone socket of a Chromecast Audio into a twenty year old amp into speakers that are supposed to be in wall but which I’ve bunged into 48 year old cabinets…not sure I need to worry about artefacts.
This is joyous however…

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Context is everything…

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I think of it as an uncertainty relationship. The sharper the brickwall corner in the frequency domain, the wider the dispersion (ringing) in the time domain and vice versa.

Linear phase has pre-ringing because all frequencies in the signal are delayed until the slowest has been passed. Frequencies that oscillate (a function of the shape of the filter) and are held back disperse equally around the central impulse time. When the filter is designed to pass frequencies at the quickest times (minimum phase) then they can only oscillate after the central impulse.

The above is just my lay understanding after reading various dsp articles that I don’t properly understand. I have been wrong before.

Looks like another article that focus exclusively on pre and post ringing. Is that really so important that we have to allow noise to cloud our judgment?

There’s nothing new we are talking about. Linear phase filters had been around since the dawn of CD and it has been used in professional mastering. Simply because it produces the lowest distortion and the best signal to noise ratio in any class of filters available. Proof of measurement and proof of accuracy reproduction of sound.

MQA is trying to bend the rule and tell us that weak and leaky filters are best for sound. Well, nobody will agree that when music is tinted with aliasing, noise and distortion is really called High Fidelity? We are not looking as a whole picture here but merely a targeted marketing scheme to get uninformed people onboard. It works for you, @Chrislayeruk but unfortunately it doesn’t work for me.

To be honest I ran into that brick wall and crashed out mentally…

The contributors of these papers are so far ahead in knowledge and competence than the average keyboard warrior, it’s funny. Still, there it is…

No, the paper makes the point that audibility of ringing is one possibility but the second is blur. Read the later sections on what blur is and what causes it.

With MQA, aliasing is around 40 dB below the noise floor at audible frequencies. Read the second paper from above (A Hierarchical…etc) and look at their plots.

I think you are missing the point here. I’m not arguing the ringing effects. I’m taking about linearity of the filter. Classic linear filters exhibit no phase distortion because they are inherently linear. Non linear filter such as MQA filter will exhibit high amount of phase distortion at high frequency.

Modern linear filters can attenuate aliasing all the way down to -100dB or more not just in the audio range but also ultrasonic range. This means there’s virtually no noise. You get ‘clean’ audio signals.

I think you are too fixated to the effects of ringings… You need medicine :joy:

Why do you think MQA filters are non-linear? Read the second paper above on their filters (which are splines). If you are thinking about their old apodizing filters, those were minimum phase and had distortion at high frequencies but they always said apodizing filters should be used at 96 kHz or above, where the phase distortion is so high as to avoid any issues.

On your second point, this history paper argues that the problems with what you call modern linear filters are ringing and blur. Read the later filtering sections.

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Since you are new here, I suggest you read this article and you will understand what I’m trying to say to you…

Long since read the Archimago paper. It has a dozen fallacies and there is no point wasting time on it.

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Probably you shouldn’t waste your time either, you are already wrong to think that MQA filter is indeed ‘linear’ and unfortunately I can’t help you on this😂