diff --git a/MixingGroup.cpp b/MixingGroup.cpp
index 64fb59a..57d05aa 100644
--- a/MixingGroup.cpp
+++ b/MixingGroup.cpp
@@ -89,6 +89,11 @@ void MixingGroup::setAction (Action a)
         if (update_action_ == ACTION_NONE)
             update_action_ = ACTION_UPDATE;
     }
+    else if (a == ACTION_FINISH) {
+        // only needs to finish if an action was done
+        if (update_action_ != ACTION_NONE)
+            update_action_ = ACTION_FINISH;
+    }
     else
         update_action_ = a;
 }
@@ -106,7 +111,15 @@ void MixingGroup::update (float)
     setActive(currentsource != sources_.end());
 
     // perform action
-    if (update_action_ == ACTION_UPDATE ) {
+    if (update_action_ == ACTION_FINISH ) {
+        // update barycenter
+        recenter();
+        // clear index, delete lines_, and recreate path and index with remaining sources
+        createLineStrip();
+        // update only once
+        update_action_ = ACTION_NONE;
+    }
+    else if (update_action_ == ACTION_UPDATE ) {
 
         std::vector<glm::vec2> p = lines_->path();
 
diff --git a/MixingGroup.h b/MixingGroup.h
index 6aace5a..de60033 100644
--- a/MixingGroup.h
+++ b/MixingGroup.h
@@ -36,7 +36,8 @@ public:
         ACTION_UPDATE = 1,
         ACTION_GRAB_ONE = 2,
         ACTION_GRAB_ALL = 3,
-        ACTION_ROTATE_ALL = 4
+        ACTION_ROTATE_ALL = 4,
+        ACTION_FINISH = 5
     } Action;
     void setAction (Action a) ;
     inline Action action () { return update_action_; }
diff --git a/MixingView.cpp b/MixingView.cpp
index 7b45227..0702ba1 100644
--- a/MixingView.cpp
+++ b/MixingView.cpp
@@ -476,7 +476,7 @@ void MixingView::terminate()
     // terminate all mixing group actions
     for (auto g = Mixer::manager().session()->beginMixingGroup();
          g != Mixer::manager().session()->endMixingGroup(); g++)
-        (*g)->setAction( MixingGroup::ACTION_NONE );
+        (*g)->setAction( MixingGroup::ACTION_FINISH );
 
 }
 
diff --git a/Source.cpp b/Source.cpp
index 82dbb2e..4aa6d94 100644
--- a/Source.cpp
+++ b/Source.cpp
@@ -60,6 +60,7 @@ Source::Source() : initialized_(false), symbol_(nullptr), active_(true), locked_
     overlay_mixinggroup_ = new Switch;
     overlay_mixinggroup_->translation_.z = 0.1;
     center = new Symbol(Symbol::CIRCLE_POINT, glm::vec3(0.f, 0.f, 0.1f));
+    center->scale_= glm::vec3(1.6f, 1.6f, 1.f);
     center->color = glm::vec4( COLOR_MIXING_GROUP, 0.96f);
     overlay_mixinggroup_->attach(center);
     rotation_mixingroup_ = new Symbol(Symbol::ROTATION, glm::vec3(0.f, 0.f, 0.1f));
@@ -304,7 +305,11 @@ void Source::setMode(Source::Mode m)
     for (auto o = overlays_.begin(); o != overlays_.end(); o++)
         (*o).second->visible_ = current & !locked_;
 
-    overlay_mixinggroup_->visible_ = mixinggroup_!= nullptr;
+    // the lock icon
+    locker_->setActive( locked_ ? 0 : 1);
+
+    // the mixing group overlay
+    overlay_mixinggroup_->visible_ = mixinggroup_!= nullptr && !locked_;
     overlay_mixinggroup_->setActive(current);
 
     // show in appearance view if current
@@ -453,8 +458,7 @@ void Source::setLocked (bool on)
 {
     locked_ = on;
 
-    // the lock icon
-    locker_->setActive( on ? 0 : 1);
+    setMode(mode_);
 }
 
 // Transfer functions from coordinates to alpha (1 - transparency)