Kvålsvoll Design Audio Forum

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Youtube Channels

I watch a lot of youtube-hosted content. For entertainment, and also to learn about specific subjects. Youtube is, or rather WAS, seen by many as a purely brainless collection of barely entertaining videos made by amateurs. This is no longer true, if it ever was true. Youtube is by far the largest collection of media content today, spanning from those brainless videos kids make just for fun, to lectures from renowned universities. Did you know there are several tutorials, of very high quality, on Blender? Bet most of you does not even know what Blender is.

But I don't watch much hifi-audio related on youtube. And why is that.

It comes down to the fact that there is not a lot of good quality hifi content out there. Compared to any other subject, both quality and number of channels are lacking.

If you want to set up a Cichlid aquarium, there will be tutorials and blogs showing how to do this, and they will usually provide useful information that does not kill your fish. If you want to know how to set up the bass-system properly, you will most likely get information that is plain wrong, ensuring that all those videos telling you subwoofers are always bad anyway, are confirmed when you listen to the results form using bad advice.

The way youtube works when providing search results and suggestions, makes it difficult to select information that is actually correct. There is no verification of the quality of the content. Popularity and monetization seems to be the most important selection criteria. Excellent for propaganda and disinformation, not so good when you want to learn and find out how things actually works.

What works:

This channel posts videos of hifi-equipment playing music at a Milan hifi-shop:

https://www.youtube.com/c/SoundSommelier

This works very well, because there are no dubious technical explanations, no hilarious claims, there is no message part from the picture and sound from the equipment, as far as I can see they do not claim the recordings as representative for the sound experienced in the rooms, it just shows the equipment accompanied by the sound of the system playing. Excellent and simple.

The recordings can of course not be a substitute for actually being there and hearing the sound, still it is possible to hear differences between the speakers, and some of their inherent characteristics do shine through.

Sound quality:

There is a common perception among audiophiles that youtube sound quality is of course sub-par to other formats, be it streaming or CD or tape or vinyl. The reality is, let us say, more complex.

First, if you watch a video, where someone is talking, it can be argued that as long as it is possible to understand the words, it does not matter anyway, sound quality is not important, beyond that it can be a better experience with better sound, especially if there is additional sound, like background music, present.

Youtube is only a transport and distribution system, it does not affect sound quality other than if the audio codec introduces audible loss or artifacts. So if the codec is reasonably good, the sound quality is determined by the program material, not by youtube.

Youtube audio codec has changed though time, they used AAC 192K, AAC 128K, and may now use Opus 251K. Opus is a very good codec, and any bit-rate from 128K and better, will be reasonably acceptable for music. This can be verified in an ABX test, comparing the youtube encoded signal to original lossless. What one will find then, is that most music, or other content as well, sounds equal to the original. Even the AAC 128K is quite good for most content, and even though it may be possible to detect small differences, it will not make any practical difference on most music material.

I do not have exact information on what codec youtube uses, you will have to contact them yourself, if details are of interest. They also may change bitrate and codec, so what is true today, may not apply next week. There is no specification.

The bigger problem is the source material. Part from the obvious recording and production, additional degradation in the transport layer may occur as content is encoded several times. Music that is uploaded from the original lossless source usually will be decent, then there are examples where material was sourced from already compressed low-bitrate mp3, and when those are re-encoded, the result is a quite substantial loss of fidelity.

So the answer to sound quality on youtube, is that the quality on the transport itself is sufficient, at least for non-critical listening, and when something sounds very bad, that is caused by bad quality of the material that was uploaded.