AAC+ streams play at the lowest quality
This issue is reproducible with any AAC+ station that uses Spectral Band Replication (SBR) extension of the AAC standard. Such stations, when played through Shortwave, have a muffled, low quality sound. The same stream played using VLC have a much better audio quality. It seems like SBR is not decoded properly, possibly other AAC+ extensions like Parametric Stereo as well.
Example: KEXP 90.3 Seattle, WA station (AAC+ version, https://www.radio-browser.info/history/961166a8-0601-11e8-ae97-52543be04c81)
- stream URL: http://live-aacplus-64.kexp.org/kexp64.aac
- the same stream URL played in VLC have a better audio quality
- the same station in the MP3 version plays just fine in Shortwave: http://live-mp3-128.kexp.org/kexp128.mp3
Another example is Radio 357 (AAC+ stream: http://193.222.135.71/378, https://www.radio-browser.info/history/e3c8273c-f0d6-4d73-b922-00d67964ff67).
To reproduce the issue, compare the audio quality of the same stream URL when played through Shortwave and for example in VLC. Tested version: 3.2.0 installed through Flatpack on Ubuntu 22.04.1