Leaderboard

Ok, got it. I've reverted to uncompressed firmware file; it's not as if it made a big difference in terms of size...

I found version 4688, dated July 2018 which seems to work Ok too. BCM4350C5_003.006.007.0221.4688.hex.zip In BrcmPatchRAM2 kext, the FirmwareKey for device 0a5c_6412 in Info.plist file must be updated to "BCM4350C5_003.006.007.0221.4688" Edit: reverted to uncompressed .hex firmware file.

Ok, I downloaded the latest driver for DW1820A I could find on Dell's web site here (Win7 64bit for XPS 9350, dated May 2019). I extracted the firmware 1707 for our 0A5C:6412 DW1820A device: BCM4350C5_003.006.007.0095.1707_v5803.hex.zip All you need to do then is: copy the uncompressed .hex firmware file to the Resources folder of BrcmFirmwareRepo kext to supersede current version 1703 (=v7 c5799) update the key for device 0a5c_6412 in Info.plist file of BrcmPatchRAM2 kext After repairing permissions and rebuilding the cache, I can now connect to my JBL USB speaker without issues: This firmware version 1707 (which equates to v7 c5803) seems to be quite old (dated December 2015) but works Ok nevertheless. I'll try and lookup for a more recent firmware than that one. Edit: reverted to uncompressed .hex firmware file.