How Well Can You Hear Audio Quality?

[m1ts0s]

http://www.npr.org/sections/therecord/2015/06/02/411473508/how-well-can-you-hear-audio-quality

 

[okakosolikos]

με το που βλέπω coldplay λέω στον εαυτό μου "μακριά".
Δεν θα χάσω την αυτοπεποίθησή μου Δευτεριάτικα έτσι εύκολα.

 

[Σ. Κωνσταντινίδης]

Εχει και το Σημίτη...δεν βρήκαν κανένα αλλο quiz ήθελα να ξερα...

 

[m1ts0s]

http://test.tidalhifi.com/

 

[m1ts0s]

Double Blind Testing

"I think the people promoting DBT show a lot of misunderstanding of neuroscience, memory, and perception. Short term, long term, makes no difference. It is not an instrument for measurement and comparison for such fine resolution. Sure if A is an apple, and B is a banana, it works fine. When A is a Pioneer and B is a Mark Levinson, that's not going to work the same way.

1. We DO NOT RECORD all input! And just in that fact alone, the use of memory should be tossed out the window. We only store essential patterns, partial inputs, enough to make the recall. If we were storing ALL sensate input in full bandwidth, our brains would have to be the size of Texas. (EX: If you drove an hour on the freeway tonight to get home, can you recall the license # of each car that passed you? The year, make and model of each car? Description of all the occupants? Obviously not---but you "saw" it all with your eyes. If you tried to store all the sound you heard in a few minutes at something like CD resolution, your brain would explode.)

2. A "memory" of a sound is not a recording of the soundwaves! Nor is it a digital representation, nor is it necessarily even stored in a contiguous brain space. Electrical impulses from the ear system are "mixed" (yeah, like a 16 track mixer) along with visual inputs, other sense inputs, emotional content, other similar patterns from previous events, and wellness stimulus. Point being, there is no discrete memory object of "just the sound" that was heard when A was played or when B was played. Proponents of this are pretending that the brain functions like a tape recorder. Ain't so.

3. DBT depends on this real time analysis: A past memory must be compared to a current stream of conscious perception and a determination for differential must be made. Well, hang on, these are two vastly different brain processes. You might as well try to compare volt meter readings to the direction a weathervane is blowing. It's nonsense. That's why it only works with "Apple and Banana" level comparisons.

There's just absolutely no science behind using DBT in audio. All the assumptions are flawed."

https://therationalaudiophile.wordpress.com/2015/06/22/article-about-listening-tests/

"Along with many other very perceptive points, the argument is that the ABX test is based on a completely flawed premise: it is not comparing audio systems using human hearing, but human memory.

I can’t vouch for whether the author and I would agree on most audio matters, but I certainly agree with him on the idea that listening tests are non-scientific on many levels."

 

[TGD]

it is not comparing audio systems using human hearing, but human memory.

Εξαιρετική ιδέα, δεν το είχα σκεφτεί ποτέ με αυτή την οπτική.

 

[Dimifoot]

Double Blind Testing

"I think the people promoting DBT show a lot of misunderstanding of neuroscience, memory, and perception. Short term, long term, makes no difference. It is not an instrument for measurement and comparison for such fine resolution. Sure if A is an apple, and B is a banana, it works fine. When A is a Pioneer and B is a Mark Levinson, that's not going to work the same way.

1. We DO NOT RECORD all input! And just in that fact alone, the use of memory should be tossed out the window. We only store essential patterns, partial inputs, enough to make the recall. If we were storing ALL sensate input in full bandwidth, our brains would have to be the size of Texas. (EX: If you drove an hour on the freeway tonight to get home, can you recall the license # of each car that passed you? The year, make and model of each car? Description of all the occupants? Obviously not---but you "saw" it all with your eyes. If you tried to store all the sound you heard in a few minutes at something like CD resolution, your brain would explode.)

2. A "memory" of a sound is not a recording of the soundwaves! Nor is it a digital representation, nor is it necessarily even stored in a contiguous brain space. Electrical impulses from the ear system are "mixed" (yeah, like a 16 track mixer) along with visual inputs, other sense inputs, emotional content, other similar patterns from previous events, and wellness stimulus. Point being, there is no discrete memory object of "just the sound" that was heard when A was played or when B was played. Proponents of this are pretending that the brain functions like a tape recorder. Ain't so.

3. DBT depends on this real time analysis: A past memory must be compared to a current stream of conscious perception and a determination for differential must be made. Well, hang on, these are two vastly different brain processes. You might as well try to compare volt meter readings to the direction a weathervane is blowing. It's nonsense. That's why it only works with "Apple and Banana" level comparisons.

There's just absolutely no science behind using DBT in audio. All the assumptions are flawed."

https://therationalaudiophile.wordpress.com/2015/06/22/article-about-listening-tests/

"Along with many other very perceptive points, the argument is that the ABX test is based on a completely flawed premise: it is not comparing audio systems using human hearing, but human memory.

I can’t vouch for whether the author and I would agree on most audio matters, but I certainly agree with him on the idea that listening tests are non-scientific on many levels."

Έντεχνη καταστρατήγηση της επιστημονικής μεθοδολογίας (κοινώς ντρίπλα) παρόμοιας τεχνικής με τις φανφάρες της ομοιοπαθητικής. Αγωνιώδης προσπάθειες καλωδιάδων. Οταν η επιστημονική μεθοδολογία καταρρίπτει όλες τις εξωφρενικές αιτιάσεις για πανάκριβα καλώδια usb και cable suspension devices αυτές ειναι οι αντιδράσεις των εμπλεκομένων, είτε ειναι πωλητές είτε αγοραστές.

 

[m1ts0s]

Θεωρεις ότι η καταστρατήγηση γίνεται απο την πλευρά των υπέρμαχων των blind test ή αυτών που είναι κατά; (Ρωταω απλώς γιατί δεν κατάλαβα έτσι όπως το γράφεις)

 

[Dimifoot]

Θεωρεις ότι η καταστρατήγηση γίνεται απο την πλευρά των υπέρμαχων των blind test ή αυτών που είναι κατά; (Ρωταω απλώς γιατί δεν κατάλαβα έτσι όπως το γράφεις)

Εννοω πως οσοι ειναι ΚΑΤΑ των double blind testing, οπως για παραδειγμα οι ομοιοπαθητικοι, ειτε δεν κατανοουν τις αρχες τις επιστημης, ειτε εχουν κατι να κρυψουν με ντριπλες. Ειτε και τα δυο. Συγνωμη αν δεν το εξεφρασα σαφως.
Επειδη ειναι αδυνατον να εξηγηθουν αυτες οι αρχες σε posts, προτεινω για αναγνωση το εκλαικευμενο "Κακη επιστημη":

https://www.skroutz.gr/books/298918.Κακή-επιστήμη.html?keyphrase=κακη+επιστημη

 

[AriPetro]

Εδω λοιπον τα αποτελεσματα που έδωσε το NPR απο το test που αναφέρει στο πρωτο ποστ ο m1ts0s.
http://www.npr.org/sections/thereco...ou-did-slightly-better-than-guessing-randomly

Αν θέλετε να κάνετε εσεις το δικό σας ABX τεστ, με τα δικά σας μουσικά κομματια που γνωρίζετε καλά δεν έχετε παρα να κατεβασετε ενα ABX tester προγραμματακι και... ιδου η ρόδος.
Τολμηστε το, δεν έχετε να χάσετε τιποτα...

 

[m1ts0s]

24/192 Music Downloads
...and why they make no sense

'Unfortunately, there is no point to distributing music in 24-bit/192kHz format. Its playback fidelity is slightly inferior to 16/44.1 or 16/48, and it takes up 6 times the space.'

'192kHz digital music files offer no benefits. They're not quite neutral either; practical fidelity is slightly worse. The ultrasonics are a liability during playback.

Neither audio transducers nor power amplifiers are free of distortion, and distortion tends to increase rapidly at the lowest and highest frequencies. If the same transducer reproduces ultrasonics along with audible content, any nonlinearity will shift some of the ultrasonic content down into the audible range as an uncontrolled spray of intermodulation distortion products covering the entire audible spectrum. Nonlinearity in a power amplifier will produce the same effect. The effect is very slight, but listening tests have confirmed that both effects can be audible.'

'In summary, it's not certain that intermodulation from ultrasonics will be audible on a given system. The added distortion could be insignificant or it could be noticable. Either way, ultrasonic content is never a benefit, and on plenty of systems it will audibly hurt fidelity. On the systems it doesn't hurt, the cost and complexity of handling ultrasonics could have been saved, or spent on improved audible range performance instead.'

'Sampling rates over 48kHz are irrelevant to high fidelity audio data, but they are internally essential to several modern digital audio techniques. Oversampling is the most relevant example.

Oversampling is simple and clever. You may recall from my A Digital Media Primer for Geeks that high sampling rates provide a great deal more space between the highest frequency audio we care about (20kHz) and the Nyquist frequency (half the sampling rate). This allows for simpler, smoother, more reliable analog anti-aliasing filters, and thus higher fidelity. This extra space between 20kHz and the Nyquist frequency is essentially just spectral padding for the analog filter.

That's only half the story. Because digital filters have few of the practical limitations of an analog filter, we can complete the anti-aliasing process with greater efficiency and precision digitally. The very high rate raw digital signal passes through a digital anti-aliasing filter, which has no trouble fitting a transition band into a tight space. After this further digital anti-aliasing, the extra padding samples are simply thrown away. Oversampled playback approximately works in reverse.

This means we can use low rate 44.1kHz or 48kHz audio with all the fidelity benefits of 192kHz or higher sampling (smooth frequency response, low aliasing) and none of the drawbacks (ultrasonics that cause intermodulation distortion, wasted space). Nearly all of today's analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) oversample at very high rates. Few people realize this is happening because it's completely automatic and hidden.'

'None of that is relevant to playback; here 24 bit audio is as useless as 192kHz sampling. The good news is that at least 24 bit depth doesn't harm fidelity. It just doesn't help, and also wastes space.'

'Why push back against 24/192? Because it's a solution to a problem that doesn't exist, a business model based on willful ignorance and scamming people. The more that pseudoscience goes unchecked in the world at large, the harder it is for truth to overcome truthiness... even if this is a small and relatively insignificant example.'

 

[AriPetro]

Back to square one, red book cd=perfect sound forever.
Elementary Watson, elementary...