gergn, CD is 1,411 kbps fixed.

gergn, where did you get the information for spotDL from? I ask because I went to the project page and found it's description "spotDL finds songs from Spotify playlists on YouTube and downloads them - along with album art, lyrics and metadata." suggesting it does NOT download songs from Spotify servers it just downloads playlist data and then parses the downloaded playlists and then searches YouTube and if matching content is found it downloads from YouTube servers NOT Spotify. If any track in the Spotify list is not found on YouTube due to poor titling or simply not being present then it won't be downloaded and the quality of audio on YouTube videos is incredibly variable and NEVER in MP3 format so if it presents the audio to the user in MP3 format it is an additional lossy encoding from the native YouTube MP4 Audio AAC at 128Kbps of course spotDL is of no use to you if you've already lost access to your spotify account from simply testing spotify downloaders offered here and publishing you had any success or failures!
TK

gergn, re “A CD uses 192 kbps fixed” is short for what is explained on

https://skeptics.stackexchange.com/questions/3219/are-there-any-perceptible-differences-between-the-sound-quality-of-192-versus-32

gergn, Thank you gergn.

gergn, 320kbps preset is called near CD quality 192kbps is no where near CD Quality

CD quality is UNCOMPRESSED 44,100bps x 16 bits per channel x 2 channels HARD DEFINED there is no MP3 or AAC uncompressed equivalent ken Bair is correct stack exchange article has nothing to do with CD Audio specification but MP3 audio perceived bitrates compression verses perceived quality by "A" listener not measured quality!

From cited article " I can hear a very slight difference most of the time between LAME-encoded (--alt preset standard*) MP3 files and CD audio, but only on an expensive system with terrific speaks in a quiet room. For earbuds and car listening it"
A deaf person can hear no difference at all... a persons subjective opinion with no qualifications on ambient noise levels, persons ability to place low frequencies within a sound-stage or dynamic range of their hearing or THD or frequency response of the combined signal to sound path it is pointless and deceptive to make any claims other than in that supposed case (which was not an actual case) a given outcome occurred and factually goes against every mathematical and measured test case in history.

cite:
https://www.adobe.com/uk/creativecloud/video/discover/audio-bitrate.html#:~:text=Audio%20CD%20bitrate%20is%20always,from%20around%2096%20to%20160Kbps.

https://electronics.sony.com/hi-res-audio-mp3-cd-sound-quality-comparison

https://www.cdunity.com/are-cds-higher-quality-than-digital/#:~:text=Lossless%20audio%20formats%2C%20such%20as,%2Dbit%2F44.1%20kHz).

https://www.soundguys.com/high-bitrate-audio-is-overkill-cd-quality-is-still-great-16518/
My only caveat on that article is while it is basically correct in terms of listening to a source it NOT correct in all scenarios, one should sample and digitally process track elements at a much higher higher multiple sample rate and bit rate than the resultant final downmix spec as the various stages noise and quantisation and intermodulation and harmonic distortion throughout a chain of digital modules and filters is cumulative and like high end graphics programs that may only display in 32bpp may have 64bit colour processing to reduce cumulative errors in filters and effects.

If the digitised content has no audio intricacies like phase modulation to move instruments around the sound stage front to back or no low end detail like channel separation then and you can't tell the difference either due to low end laptop speakers or being partially deaf then yeah 192kbps or even 128kbps will "sound" as good as a badly produced Audio CD but that CD would never get into the charts as most people have better hearing and if they like music have spent more than nothing on sound system even if it's to buy a decent set of ear buds to listen via. rather than put up with tiny phone or laptop default speakers.
TK

TK, see https://github.com/spotDL/spotify-downloader

"Download your Spotify playlists and songs along with album art and metadata (from YouTube if a match is found). "

So we agree spotDL does not directly downloads from Spotify, but searches YouTube to find matches from your Spotify playlists. So, it downlaods from YouTube, not from Spotify.

I do not use Spotify, but my wife uses it at home, while doing her homework for her choir.

TK, the search machine I used produced some more general links and information on this subject you might be interested in:

When a sound is digitized, reducing the number of bits used to represent each sample introduces quantization or discretization noise. This noise is often approximated as white noise. The relationship between the number of bits and the amount of noise introduced is described by the Signal-to-Noise Ratio (SNR) formula. For an ideal n-bit uniform quantizer, the SNR in decibels is given by:

SNR (dB) ≈ 6.02 * n + 1.76 Where n is the number of bits used to represent each sample

. This formula shows that:
1. Each additional bit increases the SNR by approximately 6.02 dB.
2. The dynamic range increases by about 6 dB for each bit added.
For example:
· 16-bit audio has a theoretical SNR of about 98 dB (6.02 * 16 + 1.76 ≈ 98.08 dB)
· 24-bit audio has a theoretical SNR of about 146 dB (6.02 * 24 + 1.76 ≈ 146.24 dB)
·
It's important to note that this formula assumes a full-scale sine wave input signal and that the quantization noise approximates a uniform distribution. In real-world applications, other factors like analog-to-digital converter noise and dithering can affect the actual SNR. The amount of noise introduced by reducing the bit depth is the inverse of this SNR. So, if you reduce the bit depth from 24 bits to 16 bits, you're effectively increasing the noise floor by about 48 dB (146 dB - 98 dB). This quantization noise becomes more noticeable at lower bit depths, which is why 8-bit or lower audio can sound noticeably "noisy" or "grainy" compared to higher bit depth audio.

How random is white noise, really, and how do I make it?
https://modwiggler.com/forum/viewtopic.php?t=209472

16 or 24 bit sampling?
https://www.audiomasterclass.com/blog/cd-vs-24-bit-streaming-sound-of-the-past-vs-sound-of-the-future-turntable-tips

https://community.roonlabs.com/t/can-someone-please-explain-to-me-why-and-how-a-24bit-44-1khz-file-is-considered-high-resolution/92109

https://www.reddit.com/r/audiophile/comments/de4dfr/what_happens_if_you_convert_24_bits_to_16_bits/?rdt=35673

https://www.perplexity.ai/search/if-a-sound-is-digitized-the-nu-nS8zz947TPq_DKwFk7CbDg

https://recording.org/forum-topic/mixing-song-critique/24-bit-16-bit-whats-lost

https://community.roonlabs.com/t/can-someone-please-explain-to-me-why-and-how-a-24bit-44-1khz-file-is-considered-high-resolution/92109

https://en.wikipedia.org/wiki/MP3
https://forum.audacityteam.org/t/mp3-and-wave-formats/63702

https://audiomunk.com/bit-rate-explained-for-digital-djs/
https://blog.codinghorror.com/the-great-mp3-bitrate-experiment/

https://forum.audacityteam.org/t/mp3-and-wave-formats/63702

My personal interest in audio is to make recordings of performances of my wife's choir, so that she can later hear what the audience had experienced. A choir singer herself does not hear the same the audience does during performances.

During the years I have used several devices to make the digital recordings of the complete performances. Afterwards I used Audacity to separate the individual songs, and to get rid of coughs in the audience, etc. And to export to MP3.

Shannon has learned us that you should take at least two samples per period of the highest significant frequency. A female voice frequency range covers fairly up to 350 Hz to 17KHz. Its fundamental frequency is 350Hz to 3kHz and Harmonics is 3kHz to 17kHz. Male voice covers a Frequency range of 100Hz to 8kHz. The fundamental is 100Hz to 900Hz and Harmonics is 900Hz to 8kHz. So, the 44.1 kHz sampling of a CD should suffice. But I found that in practice the spectrum of her choir would very seldom see significant energy above 8 kHz. So a sampling rate of 16 kHz would suffice.

When working with Audacity, 32 bit float is standard. I did a number of tests with 24 and 16 bit. That introduces almost white discretization noise. When playing the resulting Audacity files nor my wife, nor I could hear any differences on my quality headset. Nor could we hear any difference between the VBR MP3 Extreme 170-220 kbps and the intermediate Audacity files. So I settled for the VBR MP3 Extreme 170-220 kbps and a sampling frequency of 16 kHz as our home standard.