I was previously using a Sony HWS-BTA2W bluetooth adapter from 2007 to get sound wirelessly from my computer or phone to a set of non-bluetooth speakers. It had a problem that only happened with my linux computer. I was annoyed with this device because as the workload would increase/decrease on my computer, the audio would speed up and slow down. You could hear the pitch rise and fall if you were listening to music. This is probably by design – as part of the base level Bluetooth SBC codec that everything supports. It makes sense that if you’re talking on the phone you’d want to hear everything someone said, even if it had to be sped up or slowed down for continuity.

The pitch bend happened on all of my linux laptops: 2008 Dell Studio 17 and my 2014 ThinkPad T440s, and my 2019 Developer Edition XPS 13. I wasn’t sure about the problem being in the linux bluetooth stack or the Sony device itself. I knew there was a better solution available – and it happened to be a combination of hardware and software.

After reading all about Bluetooth codecs and wanting another way to tap into my audio interface, I decided to try another, more modern, bluetooth interface. I went with a 1Mii B06S Bluetooth 5.2 Receiver. It supports several aptX profiles, which provide higher fidelity than the base BT codecs.

Interestingly, aptX originated as a PhD thesis, then later became incarnate in a DSP chip. Then the tech changed hands though several companies (including Solid State Logic which makes my audio interface). Before finally becoming part of Qualcomm. AptX was first used in the Bluetooth stack with some Sennheiser headphones from 2009. My 2007 Sony hardware was definitely not using this tech.

AptX on Ubuntu 22.04

To make sure my computer supported these extra codecs, I had to install some extras. Partly because aptX has some patent issues (although it’s been reverse engineered), and partly because I upgraded my system to use pipewire. The best source I found was this gist:

$ sudo apt install pipewire-media-session- wireplumber

$ systemctl --user --now enable wireplumber.service

$ sudo apt install pipewire-audio-client-libraries

$ sudo cp /usr/share/doc/pipewire/examples/alsa.conf.d/99-pipewire-default.conf /etc/alsa/conf.d/

$ sudo apt install libldacbt-{abr,enc}2 libspa-0.2-bluetooth pulseaudio-module-bluetooth-

$ LANG=C pactl info | grep '^Server Name'

The important part in there is actually the link to the pipewire-extra-bt-codecs PPA for Ubuntu 22.04. I installed/removed the packages as expected and when I connected to the 1Mii B06S I can choose from all of the supported codecs in my sound settings:

I’m going to keep it on aptX HD for now and see how it sounds, but so far I’ve experienced zero pitch changes while listening to music.

Coming soon..

Next I’ll go through how I have everything hooked up in my home audio studio.