This repository contains firmware files for JBL Bluetooth speakers. All of those are official and were downloaded from the JBL server, except for the Charge 2 one, which I got from somewhere else online I don't remember.
NOTE: All firmware files marked as 8.8.8, 888 or similar are only for testing purposes and were never released publicly.
Some models have different chipsets (CSR, QCC, or Vimicro), so make sure to use correct files from corresponding directories. You can use ConnectPlus app to check what chipset speaker has.