diff --git a/libs/ardour/ardour/convolver.h b/libs/ardour/ardour/convolver.h
index 053dfd6177..0cf7972946 100644
--- a/libs/ardour/ardour/convolver.h
+++ b/libs/ardour/ardour/convolver.h
@@ -51,9 +51,13 @@ public:
 	uint32_t n_inputs () const  { return _n_inputs; }
 	uint32_t n_outputs () const { return _n_outputs; }
 
+	void clear_impdata ();
 	void restart ();
 	void run (BufferSet&, ChanMapping const&, ChanMapping const&, pframes_t, samplecnt_t);
 
+	void run_mono_buffered (float*, uint32_t);
+	void run_mono_no_latency (float*, uint32_t);
+
 protected:
 	ArdourZita::Convproc _convproc;
 
diff --git a/libs/ardour/convolver.cc b/libs/ardour/convolver.cc
index 2db7e029a9..2e2f18fa43 100644
--- a/libs/ardour/convolver.cc
+++ b/libs/ardour/convolver.cc
@@ -63,7 +63,7 @@ Convolution::add_impdata (
     samplecnt_t                 length,
     uint32_t                    channel)
 {
-	if (_configured || c_in >= _n_inputs || c_out >= _n_outputs) {
+	if (c_in >= _n_inputs || c_out >= _n_outputs) {
 		return false;
 	}
 	if (!readable || readable->readable_length_samples () <= offset || readable->n_channels () <= channel) {
@@ -74,6 +74,12 @@ Convolution::add_impdata (
 	return true;
 }
 
+void
+Convolution::clear_impdata ()
+{
+	_impdata.clear ();
+}
+
 bool
 Convolution::ready () const
 {
@@ -87,6 +93,11 @@ Convolution::restart ()
 	_convproc.cleanup ();
 	_convproc.set_options (0);
 
+	if (_impdata.empty ()) {
+		_configured = false;
+		return;
+	}
+
 	uint32_t n_part;
 
 	if (_threaded) {
@@ -316,8 +327,14 @@ Convolver::Convolver (
 void
 Convolver::run_mono_buffered (float* buf, uint32_t n_samples)
 {
-	assert (_convproc.state () == Convproc::ST_PROC);
 	assert (_irc == Mono);
+	Convolution::run_mono_buffered (buf, n_samples);
+}
+
+void
+Convolution::run_mono_buffered (float* buf, uint32_t n_samples)
+{
+	assert (_convproc.state () == Convproc::ST_PROC);
 
 	uint32_t done   = 0;
 	uint32_t remain = n_samples;
@@ -375,8 +392,14 @@ Convolver::run_stereo_buffered (float* left, float* right, uint32_t n_samples)
 void
 Convolver::run_mono_no_latency (float* buf, uint32_t n_samples)
 {
-	assert (_convproc.state () == Convproc::ST_PROC);
 	assert (_irc == Mono);
+	Convolution::run_mono_no_latency (buf, n_samples);
+}
+
+void
+Convolution::run_mono_no_latency (float* buf, uint32_t n_samples)
+{
+	assert (_convproc.state () == Convproc::ST_PROC);
 
 	uint32_t done   = 0;
 	uint32_t remain = n_samples;
diff --git a/libs/ardour/luabindings.cc b/libs/ardour/luabindings.cc
index 4dd9944750..6145ba9f85 100644
--- a/libs/ardour/luabindings.cc
+++ b/libs/ardour/luabindings.cc
@@ -2983,7 +2983,10 @@ LuaBindings::common (lua_State* L)
 		.beginClass <DSP::Convolution> ("Convolution")
 		.addConstructor <void (*) (Session&, uint32_t, uint32_t)> ()
 		.addFunction ("add_impdata", &ARDOUR::DSP::Convolution::add_impdata)
+		.addFunction ("clear_impdata", &ARDOUR::DSP::Convolution::clear_impdata)
 		.addFunction ("run", &ARDOUR::DSP::Convolution::run)
+		.addFunction ("run_mono_buffered", &ARDOUR::DSP::Convolution::run_mono_buffered)
+		.addFunction ("run_mono_no_latency", &ARDOUR::DSP::Convolution::run_mono_no_latency)
 		.addFunction ("restart", &ARDOUR::DSP::Convolution::restart)
 		.addFunction ("ready", &ARDOUR::DSP::Convolution::ready)
 		.addFunction ("latency", &ARDOUR::DSP::Convolution::latency)
@@ -3003,9 +3006,7 @@ LuaBindings::common (lua_State* L)
 
 		.deriveClass <DSP::Convolver, DSP::Convolution> ("Convolver")
 		.addConstructor <void (*) (Session&, std::string const&, DSP::Convolver::IRChannelConfig, DSP::Convolver::IRSettings)> ()
-		.addFunction ("run_mono_buffered", &ARDOUR::DSP::Convolver::run_mono_buffered)
 		.addFunction ("run_stereo_buffered", &ARDOUR::DSP::Convolver::run_stereo_buffered)
-		.addFunction ("run_mono_no_latency", &ARDOUR::DSP::Convolver::run_mono_no_latency)
 		.addFunction ("run_stereo_no_latency", &ARDOUR::DSP::Convolver::run_stereo_no_latency)
 		.endClass ()