diff --git a/app/src/main/java/xdsopl/robot36/ExponentialMovingAverage.java b/app/src/main/java/xdsopl/robot36/ExponentialMovingAverage.java
index c4ba06c..a1c7f88 100644
--- a/app/src/main/java/xdsopl/robot36/ExponentialMovingAverage.java
+++ b/app/src/main/java/xdsopl/robot36/ExponentialMovingAverage.java
@@ -18,8 +18,15 @@ public class ExponentialMovingAverage {
 		return prev = prev * (1 - alpha) + alpha * input;
 	}
 
-	public void reset(float alpha) {
+	public void alpha(float alpha) {
 		this.alpha = alpha;
+	}
+
+	public void alpha(float alpha, int order) {
+		alpha((float) Math.pow(alpha, 1.0 / order));
+	}
+
+	public void reset() {
 		prev = 0;
 	}
 }
diff --git a/app/src/main/java/xdsopl/robot36/PaulDon.java b/app/src/main/java/xdsopl/robot36/PaulDon.java
index 5234498..a2dc3f3 100644
--- a/app/src/main/java/xdsopl/robot36/PaulDon.java
+++ b/app/src/main/java/xdsopl/robot36/PaulDon.java
@@ -58,10 +58,11 @@ public class PaulDon implements Mode {
 	public int decodeScanLine(int[] evenBuffer, int[] oddBuffer, float[] scanLineBuffer, int prevPulseIndex, int scanLineSamples, float frequencyOffset) {
 		if (prevPulseIndex + beginSamples < 0 || prevPulseIndex + endSamples > scanLineBuffer.length)
 			return 0;
-		lowPassFilter.reset(evenBuffer.length / (float) channelSamples);
+		lowPassFilter.alpha(evenBuffer.length / (float) channelSamples, 2);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + beginSamples; i < prevPulseIndex + endSamples; ++i)
 			scanLineBuffer[i] = lowPassFilter.avg(scanLineBuffer[i]);
-		lowPassFilter.reset(evenBuffer.length / (float) channelSamples);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + endSamples - 1; i >= prevPulseIndex + beginSamples; --i)
 			scanLineBuffer[i] = freqToLevel(lowPassFilter.avg(scanLineBuffer[i]), frequencyOffset);
 		for (int i = 0; i < evenBuffer.length; ++i) {
diff --git a/app/src/main/java/xdsopl/robot36/RGBDecoder.java b/app/src/main/java/xdsopl/robot36/RGBDecoder.java
index 29fac62..2e80aa3 100644
--- a/app/src/main/java/xdsopl/robot36/RGBDecoder.java
+++ b/app/src/main/java/xdsopl/robot36/RGBDecoder.java
@@ -51,10 +51,11 @@ public class RGBDecoder implements Mode {
 	public int decodeScanLine(int[] evenBuffer, int[] oddBuffer, float[] scanLineBuffer, int prevPulseIndex, int scanLineSamples, float frequencyOffset) {
 		if (prevPulseIndex + beginSamples < 0 || prevPulseIndex + endSamples > scanLineBuffer.length)
 			return 0;
-		lowPassFilter.reset(evenBuffer.length / (float) greenSamples);
+		lowPassFilter.alpha(evenBuffer.length / (float) greenSamples, 2);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + beginSamples; i < prevPulseIndex + endSamples; ++i)
 			scanLineBuffer[i] = lowPassFilter.avg(scanLineBuffer[i]);
-		lowPassFilter.reset(evenBuffer.length / (float) greenSamples);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + endSamples - 1; i >= prevPulseIndex + beginSamples; --i)
 			scanLineBuffer[i] = freqToLevel(lowPassFilter.avg(scanLineBuffer[i]), frequencyOffset);
 		for (int i = 0; i < evenBuffer.length; ++i) {
diff --git a/app/src/main/java/xdsopl/robot36/RawDecoder.java b/app/src/main/java/xdsopl/robot36/RawDecoder.java
index df5fb5f..400f849 100644
--- a/app/src/main/java/xdsopl/robot36/RawDecoder.java
+++ b/app/src/main/java/xdsopl/robot36/RawDecoder.java
@@ -31,10 +31,11 @@ public class RawDecoder implements Mode {
 	public int decodeScanLine(int[] evenBuffer, int[] oddBuffer, float[] scanLineBuffer, int prevPulseIndex, int scanLineSamples, float frequencyOffset) {
 		if (prevPulseIndex < 0 || prevPulseIndex + scanLineSamples > scanLineBuffer.length)
 			return 0;
-		lowPassFilter.reset(evenBuffer.length / (float) scanLineSamples);
+		lowPassFilter.alpha(evenBuffer.length / (float) scanLineSamples, 2);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex; i < prevPulseIndex + scanLineSamples; ++i)
 			scanLineBuffer[i] = lowPassFilter.avg(scanLineBuffer[i]);
-		lowPassFilter.reset(evenBuffer.length / (float) scanLineSamples);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + scanLineSamples - 1; i >= prevPulseIndex; --i)
 			scanLineBuffer[i] = freqToLevel(lowPassFilter.avg(scanLineBuffer[i]), frequencyOffset);
 		for (int i = 0; i < evenBuffer.length; ++i) {
diff --git a/app/src/main/java/xdsopl/robot36/Robot_36_Color.java b/app/src/main/java/xdsopl/robot36/Robot_36_Color.java
index 507a97f..9ead77f 100644
--- a/app/src/main/java/xdsopl/robot36/Robot_36_Color.java
+++ b/app/src/main/java/xdsopl/robot36/Robot_36_Color.java
@@ -67,10 +67,11 @@ public class Robot_36_Color implements Mode {
 			separator += scanLineBuffer[prevPulseIndex + separatorBeginSamples + i];
 		separator /= separatorSamples;
 		boolean even = separator < 0;
-		lowPassFilter.reset(evenBuffer.length / (float) luminanceSamples);
+		lowPassFilter.alpha(evenBuffer.length / (float) luminanceSamples, 2);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + beginSamples; i < prevPulseIndex + endSamples; ++i)
 			scanLineBuffer[i] = lowPassFilter.avg(scanLineBuffer[i]);
-		lowPassFilter.reset(evenBuffer.length / (float) luminanceSamples);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + endSamples - 1; i >= prevPulseIndex + beginSamples; --i)
 			scanLineBuffer[i] = freqToLevel(lowPassFilter.avg(scanLineBuffer[i]), frequencyOffset);
 		for (int i = 0; i < evenBuffer.length; ++i) {
diff --git a/app/src/main/java/xdsopl/robot36/Robot_72_Color.java b/app/src/main/java/xdsopl/robot36/Robot_72_Color.java
index adf824b..68f47ab 100644
--- a/app/src/main/java/xdsopl/robot36/Robot_72_Color.java
+++ b/app/src/main/java/xdsopl/robot36/Robot_72_Color.java
@@ -61,10 +61,11 @@ public class Robot_72_Color implements Mode {
 	public int decodeScanLine(int[] evenBuffer, int[] oddBuffer, float[] scanLineBuffer, int prevPulseIndex, int scanLineSamples, float frequencyOffset) {
 		if (prevPulseIndex + beginSamples < 0 || prevPulseIndex + endSamples > scanLineBuffer.length)
 			return 0;
-		lowPassFilter.reset(evenBuffer.length / (float) luminanceSamples);
+		lowPassFilter.alpha(evenBuffer.length / (float) luminanceSamples, 2);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + beginSamples; i < prevPulseIndex + endSamples; ++i)
 			scanLineBuffer[i] = lowPassFilter.avg(scanLineBuffer[i]);
-		lowPassFilter.reset(evenBuffer.length / (float) luminanceSamples);
+		lowPassFilter.reset();
 		for (int i = prevPulseIndex + endSamples - 1; i >= prevPulseIndex + beginSamples; --i)
 			scanLineBuffer[i] = freqToLevel(lowPassFilter.avg(scanLineBuffer[i]), frequencyOffset);
 		for (int i = 0; i < evenBuffer.length; ++i) {