This guide shows how to record audio playing in Firefox using Audacity, with PipeWire as the audio backend. You’ll create a virtual sink to route Firefox audio into Audacity, and use qpwgraph to set up monitored playback so you can hear what you’re recording through your headset.

Prerequisites

• PipeWire (with pipewire-pulse)
• Audacity
• qpwgraph

Create a virtual sink

Create a null sink called recordbus that will act as an intermediate audio bus:

pactl load-module module-null-sink sink_name=recordbus \
  sink_properties=device.description=recordbus

This creates a virtual sink with an associated monitor source (recordbus.monitor). Firefox audio will be routed into this sink, and Audacity will record from its monitor.

Route Firefox to the virtual sink

In your PipeWire/PulseAudio volume control (e.g., pavucontrol), move Firefox’s output to the recordbus sink. Alternatively, you can do this from the command line once Firefox is playing audio:

# Find the Firefox sink input indexes
# Look for entries with application.name = "Firefox"
pactl list sink-inputs | grep -B 20 'application.name = "Firefox"' | grep 'Sink Input #'

# Move all Firefox sink inputs to recordbus
pactl list sink-inputs | grep -B 20 'application.name = "Firefox"' \
  | grep 'Sink Input #' | grep -o '[0-9]*' \
  | xargs -I{} pactl move-sink-input {} recordbus

Set the default recording source

Set recordbus.monitor as the default source so that Audacity will pick it up automatically:

pactl set-default-source recordbus.monitor

Configure Audacity

In Audacity, set the recording device to the generic PipeWire input. Since you’ve set recordbus.monitor as the default source, Audacity will capture Firefox audio from the virtual sink rather than your headset microphone.

Hit Record in Audacity and play audio in Firefox. Audacity will capture the Firefox audio stream.

Enable silent monitoring with qpwgraph

By default, you won’t hear the audio while recording because it’s being routed to the virtual sink instead of your headset. To monitor the recording through your headset, use qpwgraph to connect Audacity’s monitor outputs to your headset.

Open qpwgraph:

qpwgraph

In the graph, make these connections:

• PipeWire ALSA [audacity.bin]:monitor_FL → your headset’s playback_FL
• PipeWire ALSA [audacity.bin]:monitor_FR → your headset’s playback_FR

This routes Audacity’s monitor output to your headset so you can hear what’s being recorded in real time.

Save and activate the patchbay

To make this routing persistent and automatic:

1. In qpwgraph, go to Patchbay → Save to save the current graph connections as a patchbay file.
2. Enable Patchbay → Activated so that qpwgraph will automatically restore these connections whenever the relevant audio nodes appear.

With the patchbay activated, whenever Audacity’s audio node appears, qpwgraph will automatically connect its monitor outputs to your headset. You don’t need to manually reconnect each time.

Summary

The complete audio routing looks like this:

Firefox → recordbus (virtual sink)
                ↓
       recordbus.monitor → Audacity (recording input)
                              ↓
              Audacity monitor → Headset (via qpwgraph patchbay)

Restore your default microphone

When you’re done recording, restore your normal microphone as the default source:

pactl set-default-source alsa_input.usb-YOUR_DEVICE_NAME.analog-stereo

Replace the device name with your actual microphone’s PulseAudio source name. You can list available sources with:

pactl list sources short