diff --git a/engine/MUNGA/AUDCMP.h b/engine/MUNGA/AUDCMP.h
index 180aa68..0d27235 100644
--- a/engine/MUNGA/AUDCMP.h
+++ b/engine/MUNGA/AUDCMP.h
@@ -232,6 +232,11 @@ class AudioControlMixer:
 	public AudioComponent
 {
 public:
+	// DIAG/game-facing: expose the authored output control so game-side control
+	// broadcasts (the foot-plant intensity send) can target only volume/brightness
+	// mix stages and never Start-outputting stages.
+	AudioControlID GetOutputControlID() const { return outputControlID; }
+
 	//
 	//--------------------------------------------------------------------
 	// Construction, Destruction, Testing
@@ -307,6 +312,11 @@ class AudioControlMultiplier:
 	public AudioComponent
 {
 public:
+	// DIAG/game-facing: expose the authored output control so game-side control
+	// broadcasts (the foot-plant intensity send) can target only volume/brightness
+	// mix stages and never Start-outputting stages.
+	AudioControlID GetOutputControlID() const { return outputControlID; }
+
 	//
 	//--------------------------------------------------------------------
 	// Construction, Destruction, Testing
diff --git a/game/reconstructed/mech2.cpp b/game/reconstructed/mech2.cpp
index 8b612c4..49f0162 100644
--- a/game/reconstructed/mech2.cpp
+++ b/game/reconstructed/mech2.cpp
@@ -289,15 +289,21 @@ void
 			Component *c;
 			while ((c = it.ReadAndNext()) != NULL)
 			{
-				// Only the control-graph components (mixers/multipliers/splitters)
-				// accept the 100+ input-range ids; an AudioSource's ReceiveControl
-				// Fail()s on unknown ids, so skip the patch-source classes
-				// (Direct/Dynamic3D/Static3D -- VDATA L4 ids 1001/1002/1005).
-				{
-					int cid = (int)c->GetClassID();
-					if (cid == 1001 || cid == 1002 || cid == 1005)
-						continue;
-				}
+				// Feed ONLY the volume/brightness MIX stages (the footstep loudness
+				// inputs).  A blind broadcast misfires: mixers whose OUTPUT control
+				// is Start would forward the send as a Start and fire their sound
+				// per stride (the "chirp per step" bug -- ProgramButton clicked on
+				// every plant), and an AudioSource Fail()s on the 100+ input ids.
+				int cid = (int)c->GetClassID();
+				AudioControlID out;
+				if (cid == (int)RegisteredClass::AudioControlMixerClassID)
+					out = ((AudioControlMixer *)c)->GetOutputControlID();
+				else if (cid == (int)RegisteredClass::AudioControlMultiplierClassID)
+					out = ((AudioControlMultiplier *)c)->GetOutputControlID();
+				else
+					continue;
+				if (out != VolumeAudioControlID && out != BrightnessAudioControlID)
+					continue;
 				AudioComponent *ac = (AudioComponent *)c;
 				ac->ReceiveControl((AudioControlID)(runFamily ? 101 : 100), intensity);
 				ac->ReceiveControl((AudioControlID)(runFamily ? 100 : 101), 0.0f);