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Digital audio format 24/192, and why it does not make sense. Part 4 (and last)





Note Trans.: This is the translation of the last part of Christopher Monty's Montgomery article (created by Ogg Free Software and Vorbis) about why ordinary people have no sense in storing and playing music in 24/192 format and that can really improve the playback quality of your favorite recordings.



[ First part ]

[ Second part ]

[ Third part ]

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Finally, good news!



So what is needed to improve the quality of the digital sound that we listen to?



Best headphones


The easiest way is not digital. The most powerful improvement in sound quality for money is a good pair of headphones. Overhead or in-ear headphones, headphones of open or closed types - for the most part it does not matter. They do not even have to be expensive, although expensive headphones can be worth their money.



Remember that some headphones are expensive because they are well made, durable and sound great. Others are expensive, because these are $ 20 headphones that are styled for a few hundred dollars, advertised and are named after a brand. I will not give any specific recommendations, but I will say that, most likely, you will not find good headphones in large hardware stores, even if they specialize in music equipment.



Lossless compression format


It can be considered true that a correctly encoded OGG file (or MP3, or AAC) will be indistinguishable from the original with a moderate level of quantization.



But what about badly encoded files?



Twenty years ago, all MP3 encoders were very bad by modern standards. Many of these bad coders are still in use, presumably because their licenses are cheap and most people don’t distinguish or care about the difference in sound. Why should companies spend money and fix something if people don’t even know that it isn’t working well enough?



If you move to newer formats, such as Vorbis or AAC, then nothing will change in principle. For example, many companies and individuals have used (and still use) the low-quality standard Vorbis encoder from FFmpeg, because it comes by default with FFmpeg, and they don’t care how bad it is. AAC has an even longer history of widespread, low-quality encoders that were used to compress the loss of all major formats.



Lossless compression formats such as FLAC exclude any possibility of harming the sound quality [23] of a bad encoder, or even a good one, but not used correctly.



The second reason for the spread of lossless formats is the desire to avoid losses in the future. Each encoding and transcoding loses an increasing amount of information, even if the first encoding was ideal, it is very likely that sound artifacts will appear after the second encoding. This is important for those who want to remix or sample music. This is especially important for us, codec researchers, we need clear sound to work with.



Top Master Discs


In the test conducted by UAS, which I mentioned above , it was casually mentioned that the SACD version of the recording may sound much better than the CD. This is not because of the increased sampling rate or quantization level, but because a higher quality master disk is used to create the SACD. When recording to CD-R, the SACD still sounds as good as the original SACD, and better than the CD, because the original sound used for the SACD recording was better. Good mastering and production techniques obviously contribute to the quality of the music [24].



Recently covered in the press "Mastering for iTunes", and other similar initiatives from other labels are somewhat encouraging. What remains to be seen is whether Apple and others will “take care of the problem” after all, or is it just a lure to sell music to consumers that they already have, but are more expensive.



Environment


Another “trick to increase sales” that I would have bought into is “voluminous” records. Unfortunately, there are some technical hazards.



An old-fashioned discrete “surround sound” with several channels (5.1, 7.1, etc.) is a technical relic used in cinemas in the 1960s. However, the three-dimensional picture is limited, and the sound of the near speakers is distorted when the listener moves from the position or does not sit there initially.



We can restore and create excellent and reliable positioning systems using tools like Ambisonics. Problems are the cost of equipment for recreating surround sound and the fact that the recording encoded for the natural sound field sounds bad when played in stereo and cannot be artificially recreated properly. It is very difficult to fake an ambyphonic sound or holographic audio, the effect will be like that of 3D - it turns into a tasteless trick and kills 5% of the population.



Binaural sound is also very complex. You cannot imitate it because it sounds different to different people. People subconsciously move their heads in order to better track the source of the sound; without it, they cannot determine its location. This cannot be taken into account in the binaural recording, although it can still be achieved in a fixed situation.



These are hardly insurmountable technical obstacles. Discrete surround audio has already proven its relevance in the market, and I personally admire the possibilities offered by Ambisonic.



Coda



"I was never bothered by the music itself,

The juice was in her capacity! ”

- Flanders and Swan, “Song of Reproduction”


The most important thing is to enjoy the music, right? Modern playback quality is incomparably better than the good analog systems of the past generation. Is this question another problem of the first world ? Probably, but bad mixes and encodings tire me, distract me from music, and I am not alone.



Why am I opposed 24/192? Because this is a solution to a problem that does not exist - this is a business model built on ignorance, in order to deceive people. Moreover, pseudoscience walks the world unnoticed, and the more difficult it is to overshadow the truth of truth. Even if it is a small and completely insignificant example.



"It seems to me that it is much better to understand the universe as it is, than to persist in delusion, albeit satisfactory and encouraging"

- Carl Sagan (Carl Sagan)


What else to read



Readers gave me links to a couple of excellent works that I did not know about before writing my own article. They address many of the same issues, but in more detail.



The “High-Quality Digital Audio Coding” by Bob Stewart of Meridian Audio is incredibly capacious, albeit long. Our conclusions are somewhat different (it takes for granted a slightly wider frequency range and bit depth without special reasons), but his thought is clear and easy to follow. [Edit: I can disagree with many of his other works, but this one I like a lot]



The article “Digital Audio. Discretization Theory ”by Dan Laury of Lavry Engineering is another article highlighted by several readers. She explains my two pages on discretization, resampling, and filtering in more detail on 27 pages, with many graphs, examples, and links.



Stephane Pigeon from audiocheck.net wrote auditory tests that are available in the browser and posted them on the company's website. The test suite is relatively small, but some are directly relevant to the context of this article. They work well, and I found their quality quite good.



Notes to Part 4


23. Wired magazine believes that lossless compression formats, such as FLAC, are not always lossless formats:



Some fighters for clear sound will generally suggest not paying attention to FLAC and immediately buying WAV. [...] By purchasing WAV, you can avoid potential losses that may occur when converting to FLAC. This is rare, but it happens.


It is not true. The lossless compression process never changes the raw data under any circumstances, and FLAC is no exception.



In the event that Wired meant hardware damage to files (disk failures, memory loss, sunspots), then WAV and FLAC will be damaged. Here only FLAC has checksums and damage can be tracked. FLAC also takes up less space than WAV, which reduces the chance of accidental damage, because there is less data that can be damaged.



24. “Volume Wars” is the most frequently cited example of poor mastering in the modern industry, although not the only one. Loudness is a much older phenomenon than Wikipedia claims, since in the 1950s, artists and producers insisted on the loudest recordings. Equipment manufacturers researched and created new technologies to please record producers. More advanced vinyl mastering equipment in the 1970s and 1980s, for example, tracked and compacted track boundaries where possible, which made it possible to record higher amplitudes than the plate space usually allowed.



Modern digital technologies allow you to raise the volume to absurd levels. There is also a variety of automated, highly complex, patented digital station modules that are deployed everywhere, without a complete understanding of how they work or what they actually do.



Source: https://habr.com/ru/post/376897/



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