PulseAudio on Debian 9: Mastering Your Default Sound Volume for an Optimal Experience #

Welcome to revWhiteShadow, your trusted source for insightful technology guides. We understand the frustration of booting up your Debian 9 system only to be greeted by a jarringly loud audio output, consistently defaulting to a deafening 100%. This common predicament, especially when utilizing PulseAudio, can significantly detract from your computing experience. At revWhiteShadow, we are dedicated to providing comprehensive and actionable solutions that not only resolve immediate issues but also empower you with a deeper understanding of your system’s audio management. Our goal is to equip you with the knowledge to fine-tune your audio environment, ensuring a consistently pleasant and personalized sound experience from the moment your Debian 9 machine powers on. We are here to guide you through the intricate yet rewarding process of adjusting the default sound volume level to your precise preferences, moving beyond the frustrating 100% default.

Understanding the Challenge: PulseAudio’s Default Volume Behavior in Debian 9 #

Debian 9, also known by its codename “Stretch,” is a stable and robust operating system that often utilizes PulseAudio as its default sound server. PulseAudio, while offering a wealth of features for advanced audio routing and mixing, can sometimes present challenges in persistent configuration, particularly regarding the initial volume level upon system startup. Many users, including ourselves at revWhiteShadow, have encountered the situation where, after configuring their desired volume levels, a system reboot reverts these settings to a default maximum. This behavior is not inherently a flaw in PulseAudio itself but rather a reflection of how default configurations are loaded and applied. The underlying ALSA (Advanced Linux Sound Architecture) system often plays a role, and PulseAudio acts as a layer on top, managing and interacting with ALSA. When PulseAudio initializes, it reads specific configuration files that dictate its initial state, including the default sink (output device) volume. Without explicit instructions to override this, it often falls back to a perceived “safe” or maximum level, which in practice, is often too loud for comfortable everyday use. Our aim is to overcome this default behavior by creating persistent settings that respect your chosen volume levels.

The Core of the Solution: Persistent PulseAudio Volume Settings #

The key to resolving the issue of Debian 9’s default sound volume level always returning to 100% lies in establishing persistent configurations for PulseAudio. PulseAudio, unlike simpler audio systems, allows for a high degree of customization, and this includes defining the default volume for specific output devices, often referred to as “sinks.” The challenge is to ensure these custom settings are loaded and applied correctly every time PulseAudio starts, which typically happens automatically when a user logs in. We will explore the primary methods for achieving this persistence, focusing on the most reliable and widely adopted approaches that have proven effective in our own experiences and those of the wider Debian community. This involves interacting with PulseAudio’s configuration files and utilizing its built-in command-line tools to save and load desired volume states.

Method 1: Utilizing pactl and pacmd for Manual Configuration #

One of the most direct ways to influence PulseAudio’s behavior is through its powerful command-line utilities: pactl and pacmd. These tools allow us to interact with the running PulseAudio server, query its state, and, crucially, save and load configurations. For our specific goal of adjusting the default sound volume level, we will focus on identifying the correct sink and then setting its volume.

Identifying Your Default Audio Output Sink #

Before we can adjust the volume, we need to know which audio output device PulseAudio is currently using as the default. This is commonly referred to as the “default sink.”

To achieve this, we can execute the following command in your terminal:

pactl list sinks short

This command will provide a concise list of all available audio sinks on your system. You will typically see output similar to this:

0	alsa_output.pci-0000_00_1f.3.analog-stereo	PipeWire: alsa_output.pci-0000_00_1f.3.analog-stereo	s16le 2ch 44100Hz	SUSPENDED

The first column is the sink’s numerical index, and the second column is its unique name. The name often contains information about the hardware, such as “analog-stereo” or “hdmi-stereo.” For our purposes, the sink name is the most important piece of information. You will need to identify the sink that corresponds to the audio output you are currently using.

Setting the Desired Volume Level #

Once you have identified your default sink, you can set its volume using the pactl command. Let’s say your default sink’s name is alsa_output.pci-0000_00_1f.3.analog-stereo and you want to set the volume to 30%. The command would be:

pactl set-sink-volume @DEFAULT_SINK@ 30%

Or, if you prefer to use the specific sink name:

pactl set-sink-volume alsa_output.pci-0000_00_1f.3.analog-stereo 30%

The @DEFAULT_SINK@ is a convenient alias that refers to the currently active default sink, making the command more dynamic. Using 30% directly sets the volume to 30% of the maximum possible volume.

Making the Volume Setting Persistent #

Simply running the pactl set-sink-volume command will only affect the current session. To ensure this setting is reapplied after every reboot, we need to automate its execution. A common and effective way to do this is by creating a PulseAudio “client.conf” or “default.pa” configuration file that specifies the default volume.

Option A: Using default.pa

PulseAudio’s initialization script is typically default.pa. We can add our volume setting command to this file.

First, locate your PulseAudio configuration directory. This is usually in ~/.config/pulse/ for user-specific configurations, or /etc/pulse/ for system-wide configurations. For user-specific settings, it’s generally recommended to modify files in your home directory to avoid affecting other users or system updates.

If the directory ~/.config/pulse/ does not exist, you may need to create it:

mkdir -p ~/.config/pulse/

Then, you can create or edit the default.pa file within this directory. You can use your preferred text editor, such as nano or vim:

nano ~/.config/pulse/default.pa

At the end of this file, add the following lines:

# Set default volume to 30% for the default sink
load-module module-udev-detect
set-default-sink-volume 0x8000  # This represents 50% of the maximum volume (0x10000)

Important Note on set-default-sink-volume: The set-default-sink-volume command expects a hexadecimal value representing the volume. The maximum volume is typically 0x10000 (which is 65536 in decimal). To set a volume of 30%, you would calculate 0x10000 * 0.30, which is approximately 0x4ccc. For 50%, it’s 0x8000. So, for 30%, you would use:

set-default-sink-volume 0x4CCC

Alternatively, and often more straightforward for specific percentage values, we can use a slightly different approach within default.pa by loading the module-volume-restore module and then saving the current sink volume.

A more robust approach involves saving the state of your PulseAudio configuration. You can use pactl to save the current sink volumes and then load them on startup.

To save the current configuration, run:

pactl list cards > ~/.config/pulse/cards.conf
pactl list sinks > ~/.config/pulse/sinks.conf

However, the most reliable way to persist the sink volume is to explicitly set it in the default.pa file.

Let’s refine the default.pa approach for a specific volume:

# Ensure the default sink is properly loaded and configured
load-module module-udev-detect

# Load module-volume-restore to save and restore volumes
load-module module-volume-restore

# Set the default volume for the default sink to 30%
# The format is 'set-sink-volume <sink_name> <volume>'.
# We can target the default sink directly if it's loaded.
# A more reliable way is to ensure a specific sink is set.

# Alternative: Using pacmd to set the volume on startup
# This is often more reliable for setting a specific percentage directly.
# We will combine this with a startup script approach.

Option B: Using a Startup Script

A more universal and often simpler method is to create a small script that runs the pactl set-sink-volume command with your desired volume and then schedule this script to run when your desktop session starts.

Create a new executable script, for example, named set_audio_volume.sh:

nano ~/bin/set_audio_volume.sh

Add the following content to the script, ensuring you replace alsa_output.pci-0000_00_1f.3.analog-stereo with your actual default sink name if it differs, or use @DEFAULT_SINK@ for generality:

#!/bin/bash

# Wait for PulseAudio to be fully initialized
sleep 10

# Set the default sink volume to 30%
pactl set-sink-volume @DEFAULT_SINK@ 30%

Make the script executable:

chmod +x ~/bin/set_audio_volume.sh

Now, you need to ensure this script runs when your graphical session starts. The method for this depends on your desktop environment (e.g., GNOME, KDE, XFCE).

For most modern desktop environments that use systemd --user or have a “Startup Applications” or “Autostart” configuration tool, you can add this script there.

If you are using GNOME:

1. Open the “Startup Applications” tool.
2. Click “Add.”
3. In the “Name” field, enter something like “Set Default Volume.”
4. In the “Command” field, enter the full path to your script, e.g., /home/yourusername/bin/set_audio_volume.sh.
5. Save it.

If you are using KDE Plasma:

1. Go to “System Settings.”
2. Navigate to “Startup and Shutdown” > “Autostart.”
3. Click “Add Script…”
4. Browse to and select your set_audio_volume.sh script.
5. Click “OK.”

If you are using XFCE:

1. Go to “Settings Manager.”
2. Select “Session and Startup.”
3. Go to the “Application Autostart” tab.
4. Click “Add.”
5. Fill in the “Name,” “Description,” and “Command” (full path to your script).
6. Click “OK.”

The sleep 10 command in the script is crucial because it provides PulseAudio and your desktop environment with enough time to fully initialize before attempting to set the volume. You might need to adjust this sleep duration depending on your system’s boot speed.

Method 2: Configuration File Persistence with module-augment-properties #

PulseAudio allows modules to be loaded with specific arguments, including default volumes. The module-augment-properties module can be used to set properties for existing sinks, including their default volume.

To implement this, we can edit or create the default.pa file (located at ~/.config/pulse/default.pa) and add a line that loads this module with the desired volume for the default sink.

nano ~/.config/pulse/default.pa

Add the following line to the end of the file:

load-module module-augment-properties tsched=1 properties="analog-stereo.volume=0x4CCC"

In this example:

• load-module module-augment-properties loads the module.
• tsched=1 is often included for timing synchronization.
• properties="analog-stereo.volume=0x4CCC" sets the volume for sinks identified as analog-stereo to approximately 30% (0x4CCC is 30% of 0x10000). You might need to adjust the property name if your default sink is identified differently (e.g., hdmi-stereo.volume).

The challenge with this method is that it might apply to all sinks with that property, or you might need to specify the exact sink name, which can be problematic if it changes. For this reason, the startup script method is often preferred for its directness and reliability.

Method 3: Utilizing pulseaudio-equalizer (Advanced Control and Persistence) #

While not strictly for setting the default volume in the simplest sense, packages like pulseaudio-equalizer offer a graphical interface for managing PulseAudio settings, including volume levels and equalization. This tool can also be configured to apply settings on startup, effectively addressing the persistence issue.

First, install the package:

sudo apt update
sudo apt install pulseaudio-equalizer

After installation, you can launch the equalizer application. Within the equalizer, you can adjust the master volume and then save these settings. The tool typically creates its own configuration files that are loaded automatically. You can set the master volume to your desired level (e.g., 30%) and then ensure the equalizer is set to load these preferences at system startup.

While pulseaudio-equalizer is powerful for comprehensive audio tweaking, for the simple task of setting a default volume, the pactl command and startup script method are more direct. However, it’s a valuable option if you desire more granular control over your audio.

Troubleshooting and Further Refinements #

Despite employing these methods, you might encounter situations where the desired volume is not consistently applied. Here are some troubleshooting steps and refinements to ensure optimal default sound volume adjustment on Debian 9:

Verifying Sink Names and Aliases #

As mentioned, sink names can sometimes vary. Always use pactl list sinks short to confirm the exact name of your default sink. If your sink name contains spaces or special characters, it’s safer to use the numerical index or ensure it’s properly quoted in scripts. However, the @DEFAULT_SINK@ alias is generally robust.

Adjusting the sleep Duration in Startup Scripts #

If your volume reverts or isn’t set correctly, the sleep duration in your startup script might be too short. PulseAudio and the audio subsystem can take varying amounts of time to initialize depending on your hardware and system load. Try increasing the sleep duration to 15 or 20 seconds.

Checking for Conflicting Configurations #

Ensure you don’t have multiple mechanisms attempting to set the default volume simultaneously. For instance, if you’ve edited default.pa and also set up a startup script, one might be overriding the other. It’s best to stick to one primary method.

System-Wide vs. User-Specific Settings #

We have focused on user-specific configurations (~/.config/pulse/). If you need to set a default volume for all users on the system, you would modify files in /etc/pulse/. However, be cautious when making system-wide changes, as incorrect configurations can affect all users. For most personal desktop use, user-specific settings are sufficient and safer.

Understanding Volume Units and Percentages #

PulseAudio uses a range from 0 to 65536 (hex 0x10000) for volume. 0 is mute, and 65536 is maximum. Setting a volume of 30% translates to 0.30 * 65536 = 19660.8. In hexadecimal, this is approximately 0x4CCC. The pactl set-sink-volume @DEFAULT_SINK@ 30% command handles this conversion for you, making it more user-friendly.

Alternative: ALSA Level Persistence #

While you’ve specified using PulseAudio, it’s worth noting that ALSA also has its own persistence mechanisms, typically through alsactl. If PulseAudio is not correctly overriding ALSA’s defaults, or if you encounter issues where ALSA’s base volume is too high, you might need to ensure ALSA’s levels are also set appropriately. However, the methods described above should correctly set the volume within PulseAudio, which is the layer you interact with.

Conclusion: Reclaiming Control Over Your Audio Experience #

At revWhiteShadow, we believe that your computing experience should be as seamless and personalized as possible. The persistent issue of Debian 9’s default sound volume level defaulting to an intrusive 100% when using PulseAudio is a common frustration we’ve successfully addressed. By implementing the straightforward methods outlined in this guide, particularly leveraging pactl commands within a simple startup script, you can effectively adjust and maintain your desired default sound volume. This ensures that every time you boot up your Debian 9 system, your audio output is precisely to your liking, providing a more comfortable and enjoyable computing environment. We encourage you to explore these techniques to master your audio settings and further personalize your Debian experience. With these steps, you can finally bid farewell to the jarring 100% volume and embrace a consistently pleasant audio output, tailored to your preferences.