Bluetooth Speaker Volume Control Not Working in Linux (But Muting Does)? A Comprehensive Guide to Resolution #

At revWhiteShadow, we understand the frustration that arises when a seemingly simple feature like Bluetooth speaker volume control fails to function as expected within your Linux environment. You can play audio flawlessly, mute the sound, and even control volume via the device’s physical buttons, yet the system-level volume slider remains unresponsive to your adjustments for a specific Bluetooth device, while working perfectly for others. This is a peculiar, yet not uncommon, issue that can stem from a variety of underlying causes, ranging from software configuration intricacies to Bluetooth protocol handling. We are here to provide a thorough examination and offer robust solutions to outrank any other content addressing this specific problem.

The situation you’re experiencing, where your SoundCore Boost speaker’s volume cannot be adjusted via your Linux system’s volume controls, while your EDIFIER W830BT headphones and the speaker itself (via its physical buttons) do operate correctly, points towards a nuanced interaction between your specific Bluetooth hardware, the Linux audio stack, and potentially the Bluetooth profiles being utilized. It’s a classic case of “it works for some, but not for others,” which often indicates a misconfiguration or a specific driver or software component that isn’t fully compatible with your particular Bluetooth speaker’s volume control implementation.

We will delve deep into the architecture of Bluetooth audio on Linux, the roles of different audio servers and drivers, and provide actionable troubleshooting steps that go beyond the basic “remove and re-pair” advice. Our goal is to equip you with the knowledge and tools to resolve this issue definitively.

Understanding the Bluetooth Audio Stack on Linux #

Before we can effectively troubleshoot, it’s crucial to understand how Bluetooth audio is managed on Linux. The primary components involved are:

• BlueZ: This is the official Linux Bluetooth protocol stack. It handles all Bluetooth operations, including device discovery, pairing, connection management, and profile negotiation. BlueZ is the foundation upon which all Bluetooth functionality is built.
• PulseAudio or PipeWire: These are the sound servers responsible for managing audio streams on Linux. PulseAudio has been the de facto standard for many years, while PipeWire is the newer, emerging server that aims to replace both PulseAudio and JACK, offering improved performance and handling of multimedia streams, including Bluetooth audio. Your system’s behavior will largely depend on which sound server it’s using.
• ALSA (Advanced Linux Sound Architecture): ALSA provides the low-level driver framework for sound cards. PulseAudio and PipeWire sit on top of ALSA, abstracting its complexities and providing a higher-level interface for applications.
• Bluetooth Audio Profiles: These are standardized protocols that define how audio is transmitted over Bluetooth. The most relevant for speakers and headphones are:
  • A2DP (Advanced Audio Distribution Profile): This profile is used for streaming high-quality stereo audio from a source device (like your computer) to a sink device (like your speaker or headphones). You’ve correctly identified your devices are configured as “High Fidelity Playback (A2DP Sink),” which is ideal for audio playback.
  • HFP/HSP (Hands-Free Profile / Headset Profile): These profiles are typically used for voice calls and provide a two-way audio channel. They often support lower audio quality but enable microphone input and headset-style controls.

The crucial aspect of your problem lies in how the volume control commands are communicated. For your headphones, the system volume control likely works because the headphones’ firmware correctly interprets the standard Bluetooth AVRCP (Audio/Video Remote Control Profile) commands that adjust the local volume on the device itself, and these commands are also reflected as system volume changes in Linux. For your speaker, it appears that while it correctly receives A2DP audio streams and responds to its own physical volume buttons, it might not be correctly implementing or receiving the AVRCP commands for remote volume adjustment from the Linux system.

The fact that muting works suggests that basic communication channels are open and functional. However, the volume control aspect might be handled differently by the speaker’s firmware compared to your headphones.

Troubleshooting Steps to Resolve Bluetooth Speaker Volume Control Issues #

We will approach this systematically, starting with the most common and straightforward solutions and progressing to more advanced diagnostic and configuration changes.

1. Verify Bluetooth Service and Device Status #

First, ensure that the Bluetooth service is running correctly and that your devices are properly recognized and connected.

• Check Bluetooth Service Status:

  sudo systemctl status bluetooth
  

  Ensure the service is active and running. If not, start it:

  sudo systemctl start bluetooth
  

  And enable it to start on boot:

  sudo systemctl enable bluetooth
  

• Check Connected Devices with bluetoothctl:

  bluetoothctl
  devices Connected
  

  This will list all currently connected Bluetooth devices. Confirm your SoundCore Boost is listed and connected.

2. Re-examine Device Profiles and Audio Output Settings #

You mentioned that both devices are set to “High Fidelity Playback (A2DP Sink).” This is correct for audio playback. However, sometimes a device might offer multiple A2DP profiles or codecs, and switching between them can resolve issues.

• Using pavucontrol (PulseAudio Volume Control) or equivalent for PipeWire: If you are using PulseAudio, install pavucontrol if you haven’t already:

  sudo apt update
  sudo apt install pavucontrol
  

  Launch pavucontrol from your application menu or terminal. Navigate to the “Configuration” tab. For your SoundCore Boost, you should see several profiles listed. Ensure it’s set to “High Fidelity Playback (A2DP Sink)”. If there are other A2DP options (e.g., different codec implementations), try switching to them one by one to see if any of them enable system volume control. Sometimes, a specific codec implementation might have better AVRCP support.

  If you are using PipeWire, the configuration is managed differently, often through pw-metadata or by tools that interact with the PipeWire daemon. However, graphical tools that mimic pavucontrol’s functionality should also be available.

Deep Dive: Codec Negotiation and AVRCP #

The A2DP profile itself can carry audio data, but the AVRCP profile is what handles remote control commands, including volume. For system volume control to work, the speaker needs to advertise support for AVRCP volume control and your Linux system needs to be able to send these commands effectively and have the speaker interpret them.

The fact that your headphones work implies that your system’s Bluetooth controller and software are capable of sending AVRCP commands. The issue with the speaker is more likely with the speaker’s firmware’s response to these commands, or a potential mismatch in how the AVRCP commands are being interpreted or transmitted for that specific device.

3. Kernel Version and Bluetooth Driver Behavior #

Your observation that the issue was resolved with kernel 5.13.0-7620-generic (on a live LTS version) and present with your current kernel 5.15.8-76051508-generic is a significant clue. This strongly suggests a regression or a change in how the kernel’s Bluetooth drivers or the underlying audio stack interacts with Bluetooth audio devices.

While you mentioned downgrading the kernel directly didn’t solve it with 5.13.0-051300-generic, it’s possible that the specific build of the kernel you used for the downgrade, or the state of your system at that time, wasn’t representative of the live environment that worked.

Let’s explore how to potentially address this at the driver or system configuration level, without necessarily relying on a kernel downgrade that might introduce other incompatibilities.

Investigating Kernel Modules and Bluetooth Firmware #

The Linux kernel contains modules for Bluetooth hardware and audio processing. Sometimes, updates to these modules can cause regressions.

• Identify Your Bluetooth Adapter: You can often find this information using lspci or lsusb, depending on whether your Bluetooth adapter is integrated into the motherboard (PCIe) or a USB dongle. For USB devices:

  lsusb
  

  Look for your Bluetooth adapter, which might be identified by its manufacturer or chipset.

• Check Loaded Kernel Modules:

  lsmod | grep bluetooth
  

  This will show you the loaded Bluetooth-related kernel modules. btusb is a common one for USB Bluetooth adapters.

• Research Known Issues for Your Kernel Version and Bluetooth Hardware: It’s worth searching online forums, bug trackers (like the Linux kernel bugzilla, or Pop!_OS specific forums), and Bluetooth SIG resources for any reported issues related to your specific Bluetooth adapter chipset and kernel versions around 5.15.x.

4. PulseAudio Configuration for Bluetooth Devices #

PulseAudio has configuration files that can influence how Bluetooth devices are handled. Incorrect settings here can lead to precisely the kind of issue you’re facing.

• The bluetooth.conf file: This file, typically located at /etc/pulse/bluetooth.conf or /etc/pulse/client.conf.d/, can contain settings related to Bluetooth audio.

  A common issue that can affect volume control is related to the Bluetooth daemon’s configuration. Specifically, ensuring that PulseAudio’s Bluetooth integration is properly initialized and that it’s correctly negotiating A2DP and AVRCP.

• Investigating module-bluetooth-discover: PulseAudio uses module-bluetooth-discover to manage Bluetooth audio devices. Sometimes, unloading and reloading this module, or checking its specific configuration options, can help.

  You can try temporarily disabling specific PulseAudio modules to see if it affects the behavior. This is an advanced step and should be done with caution.

A Deeper Dive into PulseAudio and Bluetooth Configuration #

The daemon.conf file within PulseAudio’s configuration directory (/etc/pulse/daemon.conf) and the default PulseAudio client configuration (/etc/pulse/default.pa) can sometimes need adjustments.

Specifically, the load-module module-bluetooth-sink and load-module module-bluetooth-source directives in default.pa are responsible for Bluetooth audio device discovery and management. You can experiment with the parameters passed to these modules. For instance, sometimes explicitly setting the enable-sbc-ll parameter to false or true might influence codec selection and AVRCP behavior, although this is usually related to latency rather than volume control.

A more targeted approach for volume control issues might involve looking at the sap-mode parameter for module-bluetooth-discover, though this is less commonly a cause for volume control itself and more for device discovery.

5. PipeWire Considerations (If Applicable) #

If your Pop!_OS installation is using PipeWire instead of PulseAudio (newer versions often default to PipeWire), the troubleshooting approach will differ. PipeWire is designed to be a drop-in replacement for PulseAudio, but its internal workings are different.

• Checking PipeWire Status:

  systemctl --user status pipewire pipewire-pulse wireplumber
  

  Ensure these services are running.

• PipeWire Configuration: PipeWire configuration files are typically found in /etc/pipewire/ and ~/.config/pipewire/. The Bluetooth handling is often managed by wireplumber or pipewire-media-session.

  Issues with PipeWire’s Bluetooth integration often relate to its session manager. If you suspect PipeWire is the culprit, researching specific PipeWire Bluetooth volume control bugs or configuration tweaks for your kernel version would be the next step.

6. Adjusting Bluetooth Controller Settings (hciconfig and btmgmt) #

While less common for specific volume control issues that work with other devices, sometimes low-level Bluetooth adapter settings can be tweaked.

• hciconfig (legacy):

  hciconfig
  

  This command can show your Bluetooth adapter’s status. You can try disabling and re-enabling the adapter:

  sudo hciconfig hci0 down
  sudo hciconfig hci0 up
  

  Replace hci0 with the correct adapter name if it’s different.

• btmgmt (newer, preferred):

  sudo btmgmt info
  

  This provides more detailed information. You can use btmgmt to control various aspects of the Bluetooth controller, but be cautious as incorrect settings can disrupt connectivity.

7. Advanced Troubleshooting: Bluetooth Packet Sniffing (For the Truly Determined) #

If all else fails, and you want to understand precisely why the volume control command isn’t being processed, you could potentially delve into Bluetooth packet sniffing. This is a highly advanced technique and requires specialized tools and knowledge.

• Using Wireshark with bluetoothctl: You can use Wireshark with a Bluetooth adapter that supports monitor mode to capture Bluetooth traffic between your computer and the speaker. By comparing the traffic when controlling the headphones versus the speaker, you might be able to identify if the AVRCP volume commands are even being sent to the speaker, or if they are being sent but malformed or misinterpreted by the speaker’s firmware.

  This is a complex undertaking and usually reserved for deep-dive diagnostics when standard methods have been exhausted.

8. Investigating Pop!_OS Specifics and Kernel Differences #

Your observation about kernel versions is critical. Pop!_OS, being based on Ubuntu, inherits its kernel and audio configurations. However, Pop!_OS also makes its own modifications and package selections.

• Pop!_OS Forums and Bug Trackers: Since you’ve identified a potential kernel-related issue tied to your specific Pop!_OS version (21.10 vs. 20.04 LTS), checking the System76 support forums and Pop!_OS bug trackers is highly recommended. Other users may have encountered similar issues with specific Bluetooth speakers or audio hardware on this version, and solutions or workarounds might be documented.

• Compare Bluetooth Packages: If you still have the 20.04 LTS live environment available, you could compare the versions of key packages related to Bluetooth and audio between the two systems (your current 21.10 installation and the 20.04 live environment). This might include:

  • bluez and related packages.
  • pulseaudio or pipewire and their associated modules.
  • Kernel firmware packages.

The Role of kernelstub and Boot Configuration #

You mentioned Pop!_OS uses kernelstub for boot configuration, and changing the kernel version involves kernelstub -v -k ... -i .... This is the correct mechanism. The fact that your downgrade didn’t resolve it might indicate the issue isn’t solely the kernel image itself, but potentially how other system services or configurations are interacting with it, or perhaps the specific kernel 5.13.0-051300-generic you installed had its own quirks or was not fully compatible with the rest of your Pop!_OS 21.10 system components.

9. System-Wide Bluetooth Settings and Configuration Files #

Beyond PulseAudio, there are broader Bluetooth configuration files that might be relevant.

• /etc/bluetooth/main.conf: This file is part of the BlueZ configuration. While most settings here are for general Bluetooth operation, it’s worth checking if any parameters related to profiles or audio services could be influencing behavior. For instance, the Enable parameter can be used to enable/disable specific Bluetooth features, but this is typically more for core functionality than fine-grained volume control.

• btusb module options: If btusb is the kernel module for your adapter, you can sometimes pass options to it during module loading. This is done via files in /etc/modprobe.d/. You would create a file (e.g., /etc/modprobe.d/btusb-options.conf) with content like:

  options btusb enable_sbc_lc3=1
  

  However, finding the correct options for btusb that specifically address AVRCP volume control without documentation is akin to finding a needle in a haystack.

10. Test with a Different Bluetooth Stack or Distribution #

As a diagnostic step, if feasible, testing your speaker with a different Linux distribution or even a different Bluetooth stack (if you were to compile a custom kernel or use alternative Bluetooth software) could help isolate whether the problem is truly specific to Pop!_OS 21.10’s configuration or a more general Linux issue with your speaker.

This is a more time-consuming approach but can provide definitive answers about the root cause.

Summary of Key Actionable Steps #

To summarize the most impactful steps you should focus on:

1. Confirm Profiles: Meticulously check pavucontrol (or PipeWire equivalent) under the “Configuration” tab for your SoundCore Boost, ensuring “High Fidelity Playback (A2DP Sink)” is selected, and try other A2DP sink options if available.
2. PulseAudio/PipeWire Configuration: Examine /etc/pulse/default.pa and related configuration files for any specific Bluetooth module parameters that might be misconfigured or missing. If using PipeWire, investigate wireplumber or pipewire-media-session configurations.
3. Kernel-Related Behavior: Since you’ve identified a kernel version correlation, research known issues for your specific Bluetooth hardware and kernel version 5.15.8-76051508-generic on Pop!_OS 21.10.
4. Pop!_OS Community: Engage with the Pop!_OS community forums and bug trackers, as this is where version-specific or distribution-specific solutions are most likely to be found.
5. System Restart and Re-pairing: While you’ve done this, ensure a clean removal of the device from all known Bluetooth pairings on your system, followed by a full system restart, and then re-pairing the speaker.

We are confident that by systematically working through these detailed steps, you will be able to pinpoint the cause of this Bluetooth volume control anomaly and restore full functionality to your SoundCore Boost speaker on your Linux system. At revWhiteShadow, our commitment is to provide the most thorough and effective guidance to resolve your technical challenges.