I got a JBL L16 on FB Marketplace. Beautiful speaker and sounds pretty good but the app doesn't appear to exist any longer and the JBL Portable app doesn't support this speaker.
JBL Authentics L16 | Three-way speaker system with wireless streaming
JBL L16 Authentics – big, bold… and bass – audioFi.net
JBL Authentics L16 | Three-way speaker system with wireless streaming
Speakerholic: JBL L16 Decade finished
JBL AUTHENTICS-L16 REV.0 SM Service Manual download, schematics, eeprom, repair info for electronics experts