                 if param == self.volumeControl {
                     return String(format: "%.3f", floatValue)
                 }
+                if param == self.filterControl {
+                    return String(format: "%.3f HZ", floatValue)
+                }
+                // if param == other values here...
             }
-            // if param == other values here...
             return String(format: "%.3f", value?.pointee ?? 0)
         }
     }

                self.volume.gain = value
                print("volume set to \(value)")
            }
            // if param == other values here...
        }
    }

    }

    func setupRoute() {
        osc >>> filter
        filter >>> volume
        AudioKit.output = volume
    }

