DAB: horrendous MPEG-2 audio with usually ridiculously low bitrates, unless stations hog bandwidth.
DAB+: horrendous AAC-HEv2 with even lower bitrates (28kbps isn't uncommon).
HD RADIO: even worse - a proprietary codec based on AAC-HEv2. Used only in North America, of course. Because paying patents to multiple companies, with the manufacturer having a monopoly is better.
But this is all broadcasting, and like all broadcasting, its terrible.
A Mastodon instance for people interested in multimedia, codecs, assembly, SIMD, and the occasional weeb stuff.