diff --git a/docs/changelog.rst b/docs/changelog.rst
index e2c705e1..3509b93f 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -33,9 +33,9 @@ v0.20.0 (UNRELEASED)
 - Added new :class:`mopidy.mixer.Mixer` API which can be implemented by
   extensions.
 
-- Created a bundled extension, :mod:`mopidy.softwaremixer`, for controlling
-  volume in software in GStreamer's pipeline. This is Mopidy's default mixer.
-  To use this mixer, set :confval:`audio/mixer` to ``software``.
+- Created a bundled extension, :ref:`ext-softwaremixer`, for controlling volume
+  in software in GStreamer's pipeline. This is Mopidy's default mixer. To use
+  this mixer, set :confval:`audio/mixer` to ``software``.
 
 - Created an external extension, `Mopidy-ALSAMixer
   <https://github.com/mopidy/mopidy-alsamixer/>`_, for controlling volume with
diff --git a/docs/ext/external.rst b/docs/ext/external.rst
index 82b5a9d2..897d25cf 100644
--- a/docs/ext/external.rst
+++ b/docs/ext/external.rst
@@ -13,6 +13,7 @@ Mopidy also bundles some extensions:
 - :ref:`ext-stream`
 - :ref:`ext-http`
 - :ref:`ext-mpd`
+- :ref:`ext-softwaremixer`
 
 
 Mopidy-API-Explorer
diff --git a/docs/ext/softwaremixer.rst b/docs/ext/softwaremixer.rst
new file mode 100644
index 00000000..22badde8
--- /dev/null
+++ b/docs/ext/softwaremixer.rst
@@ -0,0 +1,35 @@
+.. _ext-softwaremixer:
+
+********************
+Mopidy-SoftwareMixer
+********************
+
+Mopidy-SoftwareMixer is an extension for controlling audio volume in software
+through GStreamer. It is the only mixer bundled with Mopidy and is enabled by
+default.
+
+If you use PulseAudio, the software mixer will control the per-application
+volume for Mopidy in PulseAudio, and any changes to the per-application volume
+done from outside Mopidy will be reflected by the software mixer.
+
+If you don't use PulseAudio, the mixer will adjust the volume internally in
+Mopidy's GStreamer pipeline.
+
+
+Configuration
+=============
+
+Multiple mixers can be installed and enabled at the same time, but only the
+mixer pointed to by the :confval:`audio/mixer` config value will actually be
+used.
+
+See :ref:`config` for general help on configuring Mopidy.
+
+.. literalinclude:: ../../mopidy/stream/ext.conf
+    :language: ini
+
+.. confval:: softwaremixer/enabled
+
+    If the software mixer should be enabled or not. Usually you don't want to
+    change this, but instead change the :confval:`audio/mixer` config value to
+    decide which mixer is actually used.
diff --git a/docs/index.rst b/docs/index.rst
index b117abc0..3d453741 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -51,6 +51,7 @@ Extensions
     ext/stream
     ext/http
     ext/mpd
+    ext/softwaremixer
     ext/external