diff --git a/src/processing/sound/Engine.java b/src/processing/sound/Engine.java
index a3c8cbd..c5745d1 100644
--- a/src/processing/sound/Engine.java
+++ b/src/processing/sound/Engine.java
@@ -138,7 +138,13 @@ private void createSynth(AudioDeviceManager deviceManager) {
 		if (this.synth != null) {
 			this.stopSynth(true);
 		}
-		this.inputDevice = deviceManager.getDefaultInputDeviceID();
+		// this might be -1 if there is no device with inputs. handled below.
+		System.out.println(deviceManager.USE_DEFAULT_DEVICE);
+		try {
+			this.inputDevice = deviceManager.getDefaultInputDeviceID();
+		} catch (RuntimeException e) {
+			// JPortAudioDevice throws an exception if no devices with inputs
+		}
 		this.outputDevice = deviceManager.getDefaultOutputDeviceID();
 		this.synth = JSyn.createSynthesizer(deviceManager);
 	}
@@ -191,8 +197,11 @@ private void startSynth() {
 		}
 		this.setVolume(1.0f);
 
+		// prevent IndexOutOfBoundsException on input-less devices
+		int inputChannels = this.inputDevice >= 0 ?
+			this.synth.getAudioDeviceManager().getMaxInputChannels(this.inputDevice) : 0;
 		this.synth.start(this.sampleRate,
-				this.inputDevice, this.synth.getAudioDeviceManager().getMaxInputChannels(this.inputDevice),
+				this.inputDevice, inputChannels,
 				this.outputDevice, this.synth.getAudioDeviceManager().getMaxOutputChannels(this.outputDevice));
 	}