diff --git a/libs/ardour/ardour/mute_master.h b/libs/ardour/ardour/mute_master.h
index fc390d3bce..d8d55851bf 100644
--- a/libs/ardour/ardour/mute_master.h
+++ b/libs/ardour/ardour/mute_master.h
@@ -42,10 +42,11 @@ class LIBARDOUR_API MuteMaster : public SessionHandleRef, public PBD::Stateful
 public:
 	/** deliveries to mute when the channel is "muted" */
 	enum MutePoint {
-		PreFader  = 0x1, ///< mute all pre-fader sends
-		PostFader = 0x2, ///< mute all post-fader sends
-		Listen    = 0x4, ///< mute listen out
-		Main      = 0x8  ///< mute main out
+		PreFader     = 0x1, ///< mute all pre-fader sends
+		PostFader    = 0x2, ///< mute all post-fader sends
+		Listen       = 0x4, ///< mute listen out
+		Main         = 0x8, ///< mute main out
+		SurroundSend = 0x10 ///< mute surround send (if any)
 	};
 
 	static const MutePoint AllPoints;
diff --git a/libs/ardour/ardour/presentation_info.h b/libs/ardour/ardour/presentation_info.h
index a42e233cb4..c3736f8242 100644
--- a/libs/ardour/ardour/presentation_info.h
+++ b/libs/ardour/ardour/presentation_info.h
@@ -113,25 +113,26 @@ class LIBARDOUR_API PresentationInfo : public PBD::Stateful
 		MasterOut = 0x20,
 		MonitorOut = 0x40,
 		Auditioner = 0x80,
-#ifdef MIXBUS
-		Mixbus = 0x1000,
-#endif
 		/* These are for sharing Stripable states between the GUI and other
 		 * user interfaces/control surfaces
 		 */
 		Hidden = 0x100,
-#ifdef MIXBUS
-		MixbusEditorHidden = 0x800,
-#endif
 		/* single bit indicates that the group order is set */
 		OrderSet = 0x400,
 
+#ifdef MIXBUS
+		MixbusEditorHidden = 0x800,
+		Mixbus = 0x1000,
+#endif
 		/* bus type for monitor mixes */
 		FoldbackBus = 0x2000,
 
 		/* has TriggerBox, show on TriggerUI page */
 		TriggerTrack = 0x4000,
 
+		/* bus is the surround master */
+		SurroundMaster = 0x8000,
+
 		/* special mask to delect out "state" bits */
 #ifdef MIXBUS
 		StatusMask = (Hidden | MixbusEditorHidden | TriggerTrack),
@@ -139,8 +140,14 @@ class LIBARDOUR_API PresentationInfo : public PBD::Stateful
 		StatusMask = (Hidden | TriggerTrack),
 #endif
 
+		/* dedicated [output] busses */
+		MainBus = (MasterOut|MonitorOut|FoldbackBus|SurroundMaster),
+
+		/* These can exist only once and require special attention to be removed */
+		Singleton = (MasterOut|MonitorOut|SurroundMaster),
+
 		/* special mask to delect select type bits */
-		TypeMask = (AudioBus|AudioTrack|MidiTrack|MidiBus|VCA|MasterOut|MonitorOut|Auditioner|FoldbackBus)
+		TypeMask = (AudioBus|AudioTrack|MidiTrack|MidiBus|VCA|MasterOut|MonitorOut|Auditioner|FoldbackBus|SurroundMaster)
 	};
 
 	static const Flag AllStripables; /* mask to use for any route or VCA (but not auditioner) */
@@ -178,7 +185,7 @@ class LIBARDOUR_API PresentationInfo : public PBD::Stateful
 
 	bool hidden() const { return _flags & Hidden; }
 	bool trigger_track () const { return _flags & TriggerTrack; }
-	bool special(bool with_master = true) const { return _flags & ((with_master ? MasterOut : 0)|MonitorOut|Auditioner); }
+	bool special(bool with_master = true) const { return _flags & ((with_master ? MasterOut : 0)|SurroundMaster|MonitorOut|Auditioner); }
 
 	bool flag_match (Flag f) const {
 		/* no flags, match all */
diff --git a/libs/ardour/ardour/rc_configuration_vars.h b/libs/ardour/ardour/rc_configuration_vars.h
index 07cdb631b4..9d138b0f9c 100644
--- a/libs/ardour/ardour/rc_configuration_vars.h
+++ b/libs/ardour/ardour/rc_configuration_vars.h
@@ -128,11 +128,13 @@ CONFIG_VARIABLE (bool, mute_affects_pre_fader, "mute-affects-pre-fader", false)
 CONFIG_VARIABLE (bool, mute_affects_post_fader, "mute-affects-post-fader", true)
 CONFIG_VARIABLE (bool, mute_affects_control_outs, "mute-affects-control-outs", true)
 CONFIG_VARIABLE (bool, mute_affects_main_outs, "mute-affects-main-outs", true)
+CONFIG_VARIABLE (bool, mute_affects_surround_sends, "mute-affects-surround-sends", true)
 CONFIG_VARIABLE (MonitorModel, monitoring_model, "monitoring-model", ExternalMonitoring)
 CONFIG_VARIABLE (ListenPosition, listen_position, "listen-position", AfterFaderListen)
 CONFIG_VARIABLE (PFLPosition, pfl_position, "pfl-position", PFLFromAfterProcessors)
 CONFIG_VARIABLE (AFLPosition, afl_position, "afl-position", AFLFromAfterProcessors)
 CONFIG_VARIABLE (bool, use_monitor_bus, "use-monitor-bus", false)
+CONFIG_VARIABLE (bool, use_surround_master, "use-surround-master", false)
 
 CONFIG_VARIABLE (bool, solo_control_is_listen_control, "solo-control-is-listen-control", false)
 CONFIG_VARIABLE (bool, exclusive_solo, "exclusive-solo", false)
diff --git a/libs/ardour/ardour/stripable.h b/libs/ardour/ardour/stripable.h
index 509e8d712c..5d46d34929 100644
--- a/libs/ardour/ardour/stripable.h
+++ b/libs/ardour/ardour/stripable.h
@@ -76,6 +76,9 @@ class LIBARDOUR_API Stripable : public SessionObject,
 	bool is_master() const { return _presentation_info.flags() & PresentationInfo::MasterOut; }
 	bool is_monitor() const { return _presentation_info.flags() & PresentationInfo::MonitorOut; }
 	bool is_foldbackbus() const { return _presentation_info.flags() & PresentationInfo::FoldbackBus; }
+	bool is_surround_master() const { return _presentation_info.flags() & PresentationInfo::SurroundMaster; }
+	bool is_main_bus() const { return _presentation_info.flags() & PresentationInfo::MainBus; }
+	bool is_singleton () const { return _presentation_info.flags() & PresentationInfo::Singleton; }
 
 	int set_state (XMLNode const&, int);
 
diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h
index 82f0c3b897..13451917d0 100644
--- a/libs/ardour/ardour/types.h
+++ b/libs/ardour/ardour/types.h
@@ -176,6 +176,12 @@ enum AutomationType {
 	InsertReturnLevel,
 	MainOutVolume,
 	MidiVelocityAutomation,
+	PanSurroundX,
+	PanSurroundY,
+	PanSurroundZ,
+	PanSurroundSize,
+	PanSurroundSnap,
+	BinauralRenderMode,
 
 	/* used only by Controllable Descriptor to access send parameters */
 
@@ -959,7 +965,6 @@ struct ProcessedRanges {
 	ProcessedRanges() : start { 0, 0 }, end { 0, 0 }, cnt (0) {}
 };
 
-
 } // namespace ARDOUR
 
 /* for now, break the rules and use "using" to make this "global" */
diff --git a/libs/ardour/ardour/uri_map.h b/libs/ardour/ardour/uri_map.h
index 2cefa42448..efedf7fa01 100644
--- a/libs/ardour/ardour/uri_map.h
+++ b/libs/ardour/ardour/uri_map.h
@@ -101,6 +101,18 @@ public:
 		uint32_t auto_end;
 		uint32_t auto_parameter;
 		uint32_t auto_value;
+		uint32_t surr_MetaData;
+		uint32_t surr_Channel;
+		uint32_t surr_PosX;
+		uint32_t surr_PosY;
+		uint32_t surr_PosZ;
+		uint32_t surr_Size;
+		uint32_t surr_Snap;
+		uint32_t surr_Settings;
+		uint32_t surr_BinauralRenderMode;
+		uint32_t surr_ChannelCount;
+		uint32_t surr_DownmixMode;
+		uint32_t surr_WarpMode;
 #endif
 	};
 
diff --git a/libs/ardour/automatable.cc b/libs/ardour/automatable.cc
index 8034b56eec..3d5bab25a7 100644
--- a/libs/ardour/automatable.cc
+++ b/libs/ardour/automatable.cc
@@ -209,6 +209,18 @@ Automatable::describe_parameter (Evoral::Parameter param)
 		return _("Width");
 	} else if (param.type() == PanElevationAutomation) {
 		return _("Elevation");
+	} else if (param.type() == PanSurroundX) {
+		return _("Left/Right");
+	} else if (param.type() == PanSurroundY) {
+		return _("Front/Back");
+	} else if (param.type() == PanSurroundZ) {
+		return _("Elevation");
+	} else if (param.type() == PanSurroundSize) {
+		return _("Object Size");
+	} else if (param.type() == PanSurroundSnap) {
+		return _("Snap to Speaker");
+	} else if (param.type() == BinauralRenderMode) {
+		return _("Binaural Render mode");
 	} else if (param.type() == PhaseAutomation) {
 		return _("Polarity Invert");
 	} else if (param.type() == MidiVelocityAutomation) {
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index f3bc258575..b24f945608 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -210,6 +210,12 @@ setup_enum_writer ()
 	REGISTER_ENUM (InsertReturnLevel);
 	REGISTER_ENUM (MainOutVolume);
 	REGISTER_ENUM (MidiVelocityAutomation);
+	REGISTER_ENUM (PanSurroundX);
+	REGISTER_ENUM (PanSurroundY);
+	REGISTER_ENUM (PanSurroundZ);
+	REGISTER_ENUM (PanSurroundSize);
+	REGISTER_ENUM (PanSurroundSnap);
+	REGISTER_ENUM (BinauralRenderMode);
 	REGISTER (_AutomationType);
 
 	REGISTER_ENUM (Off);
@@ -727,6 +733,7 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (MuteMaster, PostFader);
 	REGISTER_CLASS_ENUM (MuteMaster, Listen);
 	REGISTER_CLASS_ENUM (MuteMaster, Main);
+	REGISTER_CLASS_ENUM (MuteMaster, SurroundSend);
 	REGISTER_BITS (_MuteMaster_MutePoint);
 
 	REGISTER_CLASS_ENUM (IO, Input);
@@ -807,6 +814,7 @@ setup_enum_writer ()
 	REGISTER_CLASS_ENUM (PresentationInfo, OrderSet);
 	REGISTER_CLASS_ENUM (PresentationInfo, FoldbackBus);
 	REGISTER_CLASS_ENUM (PresentationInfo, TriggerTrack);
+	REGISTER_CLASS_ENUM (PresentationInfo, SurroundMaster);
 #ifdef MIXBUS
 	REGISTER_CLASS_ENUM (PresentationInfo, MixbusEditorHidden);
 #endif
diff --git a/libs/ardour/event_type_map.cc b/libs/ardour/event_type_map.cc
index 5a87e25901..c2270d8acd 100644
--- a/libs/ardour/event_type_map.cc
+++ b/libs/ardour/event_type_map.cc
@@ -172,6 +172,24 @@ EventTypeMap::from_symbol(const string& str) const
 		p_type = MonitoringAutomation;
 	} else if (str == "pan-lfe") {
 		p_type = PanLFEAutomation;
+	} else if (str.length() > 10 && str.substr(0, 10) == "pan-sur-x-") {
+		p_type = PanSurroundX;
+		p_id = atoi(str.c_str()+10);
+	} else if (str.length() > 10 && str.substr(0, 10) == "pan-sur-y-") {
+		p_id = atoi(str.c_str()+10);
+		p_type = PanSurroundY;
+	} else if (str.length() > 10 && str.substr(0, 10) == "pan-sur-z-") {
+		p_id = atoi(str.c_str()+10);
+		p_type = PanSurroundZ;
+	} else if (str.length() > 13 && str.substr(0, 13) == "pan-sur-size-") {
+		p_id = atoi(str.c_str()+13);
+		p_type = PanSurroundSize;
+	} else if (str.length() > 13 && str.substr(0, 13) == "pan-sur-snap-") {
+		p_id = atoi(str.c_str()+13);
+		p_type = PanSurroundSnap;
+	} else if (str.length() > 21 && str.substr(0, 21) == "binaural-render-mode-") {
+		p_type = BinauralRenderMode;
+		p_id = atoi(str.c_str()+21);
 	} else if (str.length() > 10 && str.substr(0, 10) == "parameter-") {
 		p_type = PluginAutomation;
 		p_id = atoi(str.c_str()+10);
@@ -254,6 +272,18 @@ EventTypeMap::to_symbol(const Evoral::Parameter& param) const
 		return "pan-frontback";
 	} else if (t == PanLFEAutomation) {
 		return "pan-lfe";
+	} else if (t == PanSurroundX) {
+		return std::string("pan-sur-x-") + PBD::to_string(param.id());
+	} else if (t == PanSurroundY) {
+		return std::string("pan-sur-y-") + PBD::to_string(param.id());
+	} else if (t == PanSurroundZ) {
+		return std::string("pan-sur-z-") + PBD::to_string(param.id());
+	} else if (t == PanSurroundSize) {
+		return std::string("pan-sur-size-") + PBD::to_string(param.id());
+	} else if (t == PanSurroundSnap) {
+		return std::string("pan-sur-snap-") + PBD::to_string(param.id());
+	} else if (t == BinauralRenderMode) {
+		return std::string("binaural-render-mode-") + PBD::to_string(param.id());
 	} else if (t == SoloAutomation) {
 		return "solo";
 	} else if (t == MuteAutomation) {
diff --git a/libs/ardour/luabindings.cc b/libs/ardour/luabindings.cc
index a76f6df325..e9f9e6d04b 100644
--- a/libs/ardour/luabindings.cc
+++ b/libs/ardour/luabindings.cc
@@ -1378,6 +1378,7 @@ LuaBindings::common (lua_State* L)
 		.addFunction ("is_private_route", &Stripable::is_private_route)
 		.addFunction ("is_master", &Stripable::is_master)
 		.addFunction ("is_monitor", &Stripable::is_monitor)
+		.addFunction ("is_surround_master", &Stripable::is_surround_master)
 		.addFunction ("is_hidden", &Stripable::is_hidden)
 		.addFunction ("is_selected", &Stripable::is_selected)
 		.addFunction ("gain_control", &Stripable::gain_control)
diff --git a/libs/ardour/mute_master.cc b/libs/ardour/mute_master.cc
index 7f1a8597d4..f6e868518d 100644
--- a/libs/ardour/mute_master.cc
+++ b/libs/ardour/mute_master.cc
@@ -39,7 +39,7 @@ using namespace std;
 const string MuteMaster::xml_node_name (X_("MuteMaster"));
 
 const MuteMaster::MutePoint MuteMaster::AllPoints = MuteMaster::MutePoint(
-	PreFader|PostFader|Listen|Main);
+	PreFader|PostFader|Listen|Main|SurroundSend);
 
 MuteMaster::MuteMaster (Session& s, Muteable& m, const std::string&)
 	: SessionHandleRef (s)
@@ -66,6 +66,10 @@ MuteMaster::MuteMaster (Session& s, Muteable& m, const std::string&)
 	if (Config->get_mute_affects_main_outs ()) {
 		_mute_point = MutePoint (_mute_point | Main);
 	}
+
+	if (Config->get_mute_affects_surround_sends ()) {
+		_mute_point = MutePoint (_mute_point | SurroundSend);
+	}
 }
 
 void
diff --git a/libs/ardour/parameter_descriptor.cc b/libs/ardour/parameter_descriptor.cc
index 3a0a1954d5..a4fed84675 100644
--- a/libs/ardour/parameter_descriptor.cc
+++ b/libs/ardour/parameter_descriptor.cc
@@ -102,6 +102,31 @@ ParameterDescriptor::ParameterDescriptor(const Evoral::Parameter& parameter)
 		upper  = 2.0f;
 		normal = 1.0f;
 		break;
+	case PanSurroundX:
+		upper  = 1.0f;
+		normal = 0.5f;
+		break;
+	case PanSurroundY:
+		upper  = 1.0f;
+		normal = 0.0f;
+		break;
+	case PanSurroundZ:
+	case PanSurroundSize:
+		upper  = 1.0f;
+		normal = 0.0f;
+		break;
+	case BinauralRenderMode:
+		enumeration = true;
+		integer_step = true;
+		upper  = 3.0f;
+		normal = 0.0f;
+		scale_points = std::shared_ptr<ScalePoints>(new ScalePoints());
+		scale_points->insert (std::make_pair (_("Mid"), 0));
+		scale_points->insert (std::make_pair (_("Off"), 1));
+		scale_points->insert (std::make_pair (_("Near"), 2));
+		scale_points->insert (std::make_pair (_("Far"), 3));
+		break;
+	case PanSurroundSnap:
 	case SoloAutomation:
 	case MuteAutomation:
 		upper  = 1.0f;
diff --git a/libs/ardour/presentation_info.cc b/libs/ardour/presentation_info.cc
index e28a628720..94a1844dfa 100644
--- a/libs/ardour/presentation_info.cc
+++ b/libs/ardour/presentation_info.cc
@@ -116,8 +116,8 @@ const PresentationInfo::order_t PresentationInfo::max_order = UINT32_MAX;
 const PresentationInfo::Flag PresentationInfo::Bus = PresentationInfo::Flag (PresentationInfo::AudioBus|PresentationInfo::MidiBus);
 const PresentationInfo::Flag PresentationInfo::Track = PresentationInfo::Flag (PresentationInfo::AudioTrack|PresentationInfo::MidiTrack);
 const PresentationInfo::Flag PresentationInfo::Route = PresentationInfo::Flag (PresentationInfo::Bus|PresentationInfo::Track);
-const PresentationInfo::Flag PresentationInfo::AllRoutes = PresentationInfo::Flag (PresentationInfo::Route|PresentationInfo::MasterOut|PresentationInfo::MonitorOut|PresentationInfo::FoldbackBus);
-const PresentationInfo::Flag PresentationInfo::MixerRoutes = PresentationInfo::Flag (PresentationInfo::Route|PresentationInfo::MasterOut|PresentationInfo::MonitorOut);
+const PresentationInfo::Flag PresentationInfo::AllRoutes = PresentationInfo::Flag (PresentationInfo::Route|PresentationInfo::MasterOut|PresentationInfo::MonitorOut|PresentationInfo::FoldbackBus|PresentationInfo::SurroundMaster);
+const PresentationInfo::Flag PresentationInfo::MixerRoutes = PresentationInfo::Flag (PresentationInfo::Route|PresentationInfo::MasterOut|PresentationInfo::MonitorOut|PresentationInfo::SurroundMaster);
 const PresentationInfo::Flag PresentationInfo::AllStripables = PresentationInfo::Flag (PresentationInfo::AllRoutes|PresentationInfo::VCA);
 const PresentationInfo::Flag PresentationInfo::MixerStripables = PresentationInfo::Flag (PresentationInfo::MixerRoutes|PresentationInfo::VCA);
 const PresentationInfo::Flag PresentationInfo::MidiIndicatingFlags = PresentationInfo::Flag (PresentationInfo::MidiTrack|PresentationInfo::MidiBus);
diff --git a/libs/ardour/uri_map.cc b/libs/ardour/uri_map.cc
index 217591a7d3..88a7caed3e 100644
--- a/libs/ardour/uri_map.cc
+++ b/libs/ardour/uri_map.cc
@@ -76,6 +76,20 @@ URIMap::URIDs::init(URIMap& uri_map)
 	auto_end           = uri_map.uri_to_id(LV2_AUTOMATE_URI__end);
 	auto_parameter     = uri_map.uri_to_id(LV2_AUTOMATE_URI__parameter);
 	auto_value         = uri_map.uri_to_id(LV2_AUTOMATE_URI__value);
+
+	surr_MetaData = uri_map.uri_to_id("urn:ardour:a-vapor#MetaData");
+	surr_Channel  = uri_map.uri_to_id("urn:ardour:a-vapor#Channel");
+	surr_PosX     = uri_map.uri_to_id("urn:ardour:a-vapor#PosX");
+	surr_PosY     = uri_map.uri_to_id("urn:ardour:a-vapor#PosY");
+	surr_PosZ     = uri_map.uri_to_id("urn:ardour:a-vapor#PosZ");
+	surr_Size     = uri_map.uri_to_id("urn:ardour:a-vapor#Size");
+	surr_Snap     = uri_map.uri_to_id("urn:ardour:a-vapor#Snap");
+
+	surr_Settings           = uri_map.uri_to_id("urn:ardour:a-vapor#Settings");
+	surr_BinauralRenderMode = uri_map.uri_to_id("urn:ardour:a-vapor#BinauralRenderMode");
+	surr_ChannelCount       = uri_map.uri_to_id("urn:ardour:a-vapor#ChannelCount");
+	surr_DownmixMode        = uri_map.uri_to_id("urn:ardour:a-vapor#DownmixMode");
+	surr_WarpMode           = uri_map.uri_to_id("urn:ardour:a-vapor#WarpMode");
 #endif
 }