I have no idea how Audacity creates those Line and Mic labels and how do they work exactly for a virtual device. The output of the application above (sent to hw:1,0) could be recorded in Audacity by selecting as input Loopback: PCM (hw:1,1): Line:0. Yet it worked from the monitor of loopback.

It should be noted that the parameters of the sound are controlled by the first application that opens one of the loopback devices.Īlthough Pulseaudio can connect to ALSA devices, I had no luck on getting sound from loopback input.

From here, things get simple: one application outputs sound to hw:1,0 and the other records that sound from hw:1,1. In this example you can see that the virtual devices are hw:1,0 and hw:1,1. Example output:Ĭard 1: Loopback, device 0: Loopback PCM Ĭard 1: Loopback, device 1: Loopback PCM You can view them using aplay -l command. The Virtual Sink is still there.ĪLSA makes use of a virtual loopback module. Load-module module-null-sink sink_name=Virtual_Sink sink_properties=scription=Virtual_Sink To make it permanent, open the configuration file ( sudo gedit /etc/pulse/default.pa) and add the following line: All it takes is to restart Pulseaudio and the Virtual_Sink is lost. Even worse, not all applications that support Pulseaudio provide a sound device selection dialog.īefore trying a different approach, if this worked for you, you should know that this setup is not permanent. Unfortunately not all applications support Pulseaudio. Pulseaudio creates a monitor device for each output device that can be used to record what's being outputted. To use this stream as sound input, you must use an application with Pulseaudio support and select the Monitor of Virtual_Sink as input. Select the virtual sink in Sound Settings Unfortunately, this sets the virtual sink as default output device for all applications. If you use an application with Pulseaudio support but with no way of selecting the sound card, you can set it to output sound through the Virtual_Sink in the Sound Settings. To test this, open and application that outputs sound and select Virtual_Sink. If you open Sound Settings, a new output device should have appeared, named Virtual_Sink. You should see no error after running this command. Pacmd load-module module-null-sink sink_name=Virtual_Sink sink_properties=scription=Virtual_Sink

Virtual loopback cable