text: //
  //  AKLowPassButterworthFilterAudioUnit.h
  //  AudioKit
  //
  //  Created by Aurelius Prochazka, revision history on Github.
  //  Copyright (c) 2016 Aurelius Prochazka. All rights reserved.
  //
  
  #ifndef AKLowPassButterworthFilterAudioUnit_h
  #define AKLowPassButterworthFilterAudioUnit_h
  
  #import <AudioToolbox/AudioToolbox.h>
  
  @interface AKLowPassButterworthFilterAudioUnit : AUAudioUnit
  @property (nonatomic) float cutoffFrequency;
  
  - (void)start;
  - (void)stop;
  - (BOOL)isPlaying;
  - (void)setUpParameterRamp;
  - (BOOL)isSetUp;
  
  @property double rampTime;
  
  @end
  
  #endif /* AKLowPassButterworthFilterAudioUnit_h */
  