fix vfx based presets

Assets/WasapiAudio/Scripts/Unity/VfxAudioVisualizationEffect.cs

@@ -17,7 +17,7 @@ namespace Assets.WasapiAudio.Scripts.Unity
         [SpectrumDataPreview]
         public SpectrumData Preview;
 
-        protected int SpectrumSize { get; private set; }
+        public int SpectrumSize { get; private set; }
 
         public override bool IsValid(VisualEffect component) {
             return source != null;