I’m trying to get the HFP 1.6 wide band audio working with some Bose QC-35 headphones. They do support it. I’m using Linux. It can work in Linux and I’ve done it, just not with the Plugable USB-BT4LE adapter.
pulse-audio has issues with HFP so I’ve switched to using blue-alsa. This software does support the 16 kHz mSBC wide band voice mode when using HFP, as well as the better A2DP codecs.
I’ve gotten it to work on a Pinebook Pro’s built in bluetooth (BCM4345C5 based) with the same software setup.
When using the Plugable adapter (with multiple computers) it fails. A2DP does work (SBC and AAC), and normal 8 kHz CVSD for record and playback works, but sounds poor as expected.
The failure with wideband voice seems to be lack of support in the Plugable adapter for USB alt mode 6, which is used to transfer mSBC data over USB. These log messages appear when attempting to play audio with mSBC when it doesn’t work on the USB-BT4LE and do not appear when using the built-in adapter.
Bluetooth: hci0: Device does not support ALT setting 6 Bluetooth: hci0: urb 00000000d0f6c24f submission failed (90) Bluetooth: hci0: sending frame failed (-90)
I’ve tried getting the firmware file described on SOLVING HFP/HSP AND A2DP PROFILE ISSUES ON LINUX, and I’ve verified that the kernel driver loads it, but it made no difference.
Does USB-BT4LE support wide band audio in HFP mode?