@yellow so, with lossy codecs in particular, far lower bitrates can be used to achieve 'transparency' or where in a double blind test the listener can't tell the difference between the lossless file and the encoded
per testing that hydrogenaudio has done with opus, you hit that mark around 160kbps
and honestly, in my testing, 128kbps is absolutely excellent for on the go listening (i do still use 160kbps just to give some headroom, but i'm a dork)
the 160/192kbps transparency testing would have been found by folks listening closely on high end equipment, so like, bluetooth and environmental noise would further increase the transparency headroom