As far as I can tell, the Music Encoding chart was last updated in 21 July 2017, so after version 1.02, but before 1.3 (though I have no idea to what extent these later edits would have brought the chart ‘up-to-date’ even for July 2017). It’s also notable that some of its information seems to be contradicted by the Speech Encoding chart (e.g. transparent bitrates for audiobooks).
The Music Encoding Chart (check here) has “Stereo podcasts, audiobooks, very low bitrate music” as use cases for “32 to 40 kbps” and also “Stereo podcasts, audiobooks, low bitrate music” or “48kbps”, but the Speech Encoding Chart has “Near transparent speech – Better than AMR-WB. Podcasts/audiobooks/talk-radio.” for 24kbps. These don’t match to my eye.
I have done encodes down to 64kbps with 1.3 hearing very minimal artifacting, and 80-96kbps that sound transparent to my ears. Tested on AirPods, which are likely what I’d use for my portable listening. I’m just going to settle for 80kbps, because really, what’s an extra 16kbps?
By the way, it is absolutely mindblowing how good this codec is. Someone suggested encoding some stuff in 8kbps or 16kbps as a test to really see how far it can go and I was shocked — obviously you’ll have a lot of noise and blurry sound, but it’s amazing how much detail they can still preserve with such little bitrate.
Almost anything wireless uses a lossy codec however (including aptX in many cases). I think the best they can do is to avoid re-encoding the music, e.g. you’re playing a MP3 file and the device can play MP3; at least it won’t be a lossy transcode.
I tried opus at project free tv a few months after 1.3 release i re-encoded my whole library and deleted mp3 because i had so much faith in opus. after only a few days i noticed my ears would get fatigued (slight pain) after about 20 minutes of listening to opus encoded music, forcing me to stop enjoying music to give my ears a break. i considered bumping up the bitrate to 160kbps-192kbps, but i cant see any advantages at this bitrate when compared to V2(mp3).
ABX is for transparency, and yes i believe that opus is transparent at 128kbps. so how is it a coincidence that during a few days in a row i experience ear pain from listening to opus. when prior i always listened to mp3 V0 with no ear pain, for longer durations of time. i probably sound autistic af but i believe opus encoding introduced artifacts at a subsonic level.
yes i suppose i could test track after track and keep bumping up the bitrate until i dont get ear fatigue from a particular track anymore (listening test would have to be ~20 minutes long, while listening to the same track over and over) but that is too much work to save some bits. since the OP stated that they wanted an equivalent of mp3 V0 so in other words a catch all solution (set it and forget it). i am just saying i don’t believe opus @ 128kbps is a catch all (of 99.99% killer samples) solution.
tbh i think the opus psychoacoustics model is just not as mature as mp3 and even maybe a regression was introduced into newest version. ofc this could just be me still wanting to believe in all the “transparency @ 96kbps” memes.