DAB standard broadcast quality, which uses the old MP2 codec, was not the best sound quality mainly broadcasting between 80 – 128kbs range, apart from BBC radio 3 of all channels, which is broadcast at a higher quality 160 – 192Kbs.
DAB+ launched in 2007 or rather 2016 in the UK, and introduced in european car radios 2021. DAB+ uses the the improved HE-ACC V2 audio codec,as used in iPods, therefore DAB+ has better error correction than imporoves sound. More efficient compression allows a much lower lower broadcast kbs DAB+, for the same quality 128kbs on DAB standard. Older DAB radios’ which didn’t have the digital tick mark can’t receive DAB+ , so they share the same multiplex’s as there’s a reluctance to turn them off.
Internet radio offers by far the best audio quality, as it uses the more efficient AAC audio codec, with broadcasts at least 256kbs. The BBC for example is doing 320kbs streams for national stations, with BBC radio 3 started to deliver lossless compression over the internet, using FLAC compression, Mpeg Dash, HTML5 and media source extension, for claimed original sound quality to Firefox and Google users (not sure if this still in pilot stage or expaned).
For broadcasts to acheive whats generally accepted, as proper “high fidelity” (hifi) sound quality, it needs to be at least in 190 – 256kbs range, with the lower range being acceptable for mono broadcasts and higher value necessary for stereo.
Nonsense if your not interested but there you go 😂