Play sound through two or more outputs/devices

Question

I have one sound card and one pair of Bluetooth headphones. I want to play my audio through both my sound card and my Bluetooth headphones.

I believe Windows has checkboxes that allow you to "check" outputs to enable/disable them, but Ubuntu seemingly has the equivalent of radio selectors (you can only select one at a time).

Bonus question: On a similar note, I have 5 analog output channels on my sound card (in addition to my digital & HDMI audio) -- I would like to be able to determine what comes out of each of those ports (e.g. "front speakers" on all 5 or "front", "center", "back", etc).

Answer 1

With paprefs you have access to a virtual output device that enables simultaneous output to all attached sound cards and devices:

sudo apt install paprefs

Then in the terminal run paprefs, select Simultaneous Output tab, and check Add virtual output for simultaneous output on all local sounds cards.

The additionally created audio output device for simultaneous output may be selected in the Output tab from the PulseAudio Sound Preferences menu (pavucontrol):

In this example it is shown for an HDMI-device, but, as soon as your Bluetooth device is recognized, it will also be available for simultaneous output.

The changes may need a restart of PulseAudio to take effect, either by logging out and back in to your session or by running pulseaudio -k in a terminal.

---

In case paprefs does not do the job or if you prefer to have paprefs not installed, use this command from the command line:

pactl load-module module-combine-sink

To unload the module from the command line and reset PulseAudio to defaults, just restart PulseAudio with:

pulseaudio -k

or issue:

pactl unload-module module-combine-sink

Answer 2

Ubuntu

I've just confirmed this solution still works on Ubuntu 14.04 LTS.

1. Install: Open terminal and type sudo apt install paprefs go to the tab exactly as per the picture above and select the option.
2. Initial Run:
   1. Remaining in terminal, type pulseaudio -k to kill and restart pulseaudio (this way with current systemd pulseaudio user service).
   2. Then go to your sound settings and you will see the option to output to multiple sound devices.
   3. Props to whoever wrote paprefs it's a brilliant little piece of software I would actually like to see included in Ubuntu without requiring additional installation.

Apple Mac OS X

A similar solution is available via an included piece of software and whats so great about pulseaudio is that the sound seems to be perfectly in-sync from both outputs so it must be adjusting for the lag as well which is why its so impressive; otherwise we would be hearing a slightly delayed version from one output and another.

Answer 3

In Kubuntu 18.04, Plasma 5.12 paprefs is not needed, as a similar setting is already there:

A new output option should become available after reboot, called “Simultaneous output”.

Or in pavucontrol:

---

In 18.10 with Plasma 5.13.5 that “Simultaneous output” option has been removed, so paprefs is needed.

Answer 4

I could not get Takkat's proposal work out of the box in Debian 8.7, although I restarted the system. I assume you have completed Takkat's proposal in installing paprefs. Extension on Takkat's answer which works based on Arch Linux wiki where keep analog input and Pulse calls that "duplex"

# /etc/pulse/default.pa
# http://unix.stackexchange.com/a/180374/16920
load-module module-alsa-sink device=hdmi:0
load-module module-combine-sink sink_name=combined
set-default-sink combined

Then restart pulseaudio:

pulseaudio -k

Answer 5

Because LeonidMew was asking about 18.04 (I'm using 18.04.2), here's my version.

The GUI paprefs tried to combine one HDMI with one analog output, instead of both hdmi. So I edited the file /etc/pulse/default.pa as described by Léo Léopold Hertz

$ gedit /etc/pulse/default.pa  # make changes as in method a or b below
$ pulseaudio -k # then restart pulseaudio

Both the following methods work on their own, so pick one (make sure to add these lines to the top of the file, I put it right after .fail ! Otherwise it doesn't work).

Method A

load-module module-alsa-sink device=hw:0,0
load-module module-combine-sink sink_name=combined

Method B

load-module module-alsa-sink device=hw:1,3 sink_name=hdmi
load-module module-alsa-sink device=hw:1,7 sink_name=hdmi2
load-module module-combine-sink sink_name=combined slaves=hdmi,hdmi2
set-default-sink hdmi-combined

---

Reference

Method A

For reference, the hw:0,0 comes from aplay -l

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC892 Analog [ALC892 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 1: ALC892 Digital [ALC892 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Method B

And the 1:7 and 1:3 comes from

$ pacmd list-sinks | grep -e 'name:' -e 'alsa.device ' -e 'alsa.subdevice '
    name: <alsa_output.pci-0000_00_1b.0.iec958-stereo>
        alsa.subdevice = "0"
        alsa.device = "1"
    name: <alsa_output.pci-0000_01_00.1.hdmi-stereo-extra1>
        alsa.subdevice = "0"
        alsa.device = "7"

On the GNOME "sound settings" I set the other HDMI from 2nd monitor as output, and then re-ran the command

$ pacmd list-sinks | grep -e 'name:' -e 'alsa.device ' -e 'alsa.subdevice '
    name: <alsa_output.pci-0000_00_1b.0.iec958-stereo>
        alsa.subdevice = "0"
        alsa.device = "1"
    name: <alsa_output.pci-0000_01_00.1.hdmi-stereo>
        alsa.subdevice = "0"
        alsa.device = "3"

To verify these numbers are correct, I ran

$ aplay -D plughw:1,3 /usr/share/sounds/alsa/Front_Right.wav
$ aplay -D plughw:1,7 /usr/share/sounds/alsa/Front_Right.wav

which sounded on their respective monitors.

Answer 6

To complement the excellent answer from Takkat, I found the default name given to the new device was excessively long and distorted the Sound Settings dialog. In order to shorten that name, I had to additionally execute the following command:

gconftool --set --type string /system/pulseaudio/modules/combine/args0 sink_properties=device.description=Combined

Answer 7

With Pipewire (Ubuntu 23.04+)

Recent versions of Ubuntu use Pipewire instead of Pulseaudio. The proper way to configure Pipewire is as simple as (based on Pipewire’s Combine Stream module):

1. Create a file named 10-simultaneous-output.conf in ~/.config/pipewire/pipewire.conf.d with the following content:

context.modules = [
{   name = libpipewire-module-combine-stream
    args = {
        combine.mode = sink
        node.name = "combine_sink"
        node.description = "Simultaneous Output"
        combine.latency-compensate = false
        combine.props = {
            audio.position = [ FL FR FC LFE SL SR ]
        }
        stream.props = {
        }
        stream.rules = [
            {
                matches = [
                    # any of the items in matches needs to match, if one does,
                    # actions are emited.
                    {
                        # all keys must match the value. ! negates. ~ starts regex.
                        #node.name = "~alsa_input.*"
                        media.class = "Audio/Sink"
                    }
                ]
                actions = {
                    create-stream = {
                        combine.audio.position = [ FL FR FC LFE SL SR ]
                        audio.position = [ FL FR FC LFE SL SR ]
                    }
                }
            }
        ]
    }
}
]

2. Restart Pipewire:

systemctl --user restart pipewire.service

3. Select the new “Simultaneous Output” as output device
   • globally in the Sound Settings or the top-right menu of Gnome
   • per application via PulseAudio Volume Control (pavucontrol), which, despite the name, also manages Pipewire

That’s it!

Answer 8

Nowadays

Actually, with pipewire, just the GUI part seems to bee missing for this to work (in GNOME, as of GNOME 45).

Actually, there are many GUI tools for this and similar tasks (like distorting audio or so), just search for pipewire on Flathub e.g..

I tested some and found Helvum to be good and working for that use case.. In the self-proclaimed “graphical patchbay for PipeWire”. You can just connect the same source twice there or mix that up even more: .

I.e. drag and drop the source from the left to the right, where the audio devices are. (Note FL is left audio and FR is right audio) The disadvantage/important thing to note is the source only appears once it has audio output and you need to configure this for each application. (though, the benefit of course is, you can configure it separately)

The benefit is this also works on immutable distros.

My tries

Before using Fedora Silverblue 39 I tried using the paprefs:

$ rpm-ostree install paprefs             
Checking out tree 9450953... done
Enabled rpm-md repositories: fedora rpmfusion-free fedora-cisco-openh264 updates rpmfusion-free-updates updates-archive
Importing rpm-md... done
rpm-md repo 'fedora' (cached); generated: 2023-11-01T00:12:39Z solvables: 70825
rpm-md repo 'rpmfusion-free' (cached); generated: 2023-11-04T16:49:08Z solvables: 445
rpm-md repo 'fedora-cisco-openh264' (cached); generated: 2023-12-12T17:22:46Z solvables: 4
rpm-md repo 'updates' (cached); generated: 2024-03-18T02:04:08Z solvables: 24253
rpm-md repo 'rpmfusion-free-updates' (cached); generated: 2024-03-10T16:19:26Z solvables: 164
rpm-md repo 'updates-archive' (cached); generated: 2024-03-18T02:34:06Z solvables: 36849
Resolving dependencies... done
error: Could not depsolve transaction; 1 problem detected:
 Problem: package pulseaudio-module-gsettings-16.1-5.fc39.x86_64 from fedora requires libpulsecore-16.1.so()(64bit), but none of the providers can be installed
  - package pulseaudio-module-gsettings-16.1-5.fc39.x86_64 from fedora requires pulseaudio(x86-64) = 16.1-5.fc39, but none of the providers can be installed
  - package pipewire-pulseaudio-1.0.4-2.fc39.x86_64 from @System conflicts with pulseaudio provided by pulseaudio-16.1-5.fc39.x86_64 from fedora
  - package pipewire-pulseaudio-1.0.4-2.fc39.x86_64 from @System conflicts with pulseaudio-daemon provided by pulseaudio-16.1-5.fc39.x86_64 from fedora
  - package pulseaudio-16.1-5.fc39.x86_64 from fedora conflicts with pulseaudio-daemon provided by pipewire-pulseaudio-1.0.4-2.fc39.x86_64 from @System
  - package paprefs-1.2-5.fc39.x86_64 from fedora requires pulseaudio-module-gsettings, but none of the providers can be installed
  - conflicting requests