     
     override init() {
         super.init()
+        let filename = "CsoundLib64.framework/Sounds/PianoBassDrumLoop.wav"
         
-        let operation = AKSleighbells()
-        connect(operation)
+        let audio = AKFileInput(filename: filename)
+        connect(audio)
+        
+        let mono = AKMixedAudio(signal1: audio.leftOutput, signal2: audio.rightOutput, balance: 0.5.ak)
+        connect(mono)
         
         auxilliaryOutput = AKAudio.globalParameter()
-        assignOutput(auxilliaryOutput, to:operation)
+        assignOutput(auxilliaryOutput, to:mono)
     }
 }
 

    init(audioSource: AKAudio) {
        super.init()
        
        let line = AKLinearControl(firstPoint: 5000.ak, secondPoint: 0.ak, durationBetweenPoints: 11.ak)
        connect(line)
        
        let operation = AKHighPassButterworthFilter(input: audioSource)
        operation.cutoffFrequency = line
        connect(operation)
        
        connect(AKAudioOutput(audioSource:operation))

AKOrchestra.testForDuration(10)

processor.play()
instrument.play()

while(AKManager.sharedManager().isRunning) {} //do nothing
println("Test complete!")
