diff --git a/libs/audio/include/psemek/audio/effect/butterworth.hpp b/libs/audio/include/psemek/audio/effect/butterworth.hpp
new file mode 100644
index 00000000..8178bfde
--- /dev/null
+++ b/libs/audio/include/psemek/audio/effect/butterworth.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <psemek/audio/stream.hpp>
+
+namespace psemek::audio
+{
+
+	// Second-order
+	stream_ptr butterworth_low_pass(stream_ptr stream, float cutoff_frequency);
+	stream_ptr butterworth_high_pass(stream_ptr stream, float cutoff_frequency);
+
+}
diff --git a/libs/audio/source/butterworth.cpp b/libs/audio/source/butterworth.cpp
new file mode 100644
index 00000000..521d8789
--- /dev/null
+++ b/libs/audio/source/butterworth.cpp
@@ -0,0 +1,59 @@
+#include <psemek/audio/effect/butterworth.hpp>
+#include <psemek/audio/effect/filter.hpp>
+#include <psemek/audio/constants.hpp>
+#include <psemek/math/constants.hpp>
+
+namespace psemek::audio
+{
+
+	stream_ptr butterworth_low_pass(stream_ptr stream, float cutoff_frequency)
+	{
+		float omega = 2.f * static_cast<float>(math::pi) * cutoff_frequency * audio::inv_frequency;
+		omega = 2.f * audio::frequency * std::tan(omega / 2.f);
+
+		float gamma = 2.f * audio::frequency / omega;
+		float sqrt2 = std::sqrt(2.f);
+
+		float a0 = gamma * gamma + sqrt2 * gamma + 1.f;
+		float a1 = - 2.f * gamma * gamma + 2.f;
+		float a2 = gamma * gamma - sqrt2 * gamma + 1.f;
+
+		float b0 = 1.f;
+		float b1 = 2.f;
+		float b2 = 1.f;
+
+		a1 /= a0;
+		a2 /= a0;
+		b0 /= a0;
+		b1 /= a0;
+		b2 /= a0;
+
+		return linear_filter(std::move(stream), {a1, a2}, {b0, b1, b2});
+	}
+
+	stream_ptr butterworth_high_pass(stream_ptr stream, float cutoff_frequency)
+	{
+		float omega = 2.f * static_cast<float>(math::pi) * (audio::frequency / 2.f - cutoff_frequency) * audio::inv_frequency;
+		omega = 2.f * audio::frequency * std::tan(omega / 2.f);
+
+		float gamma = 2.f * audio::frequency / omega;
+		float sqrt2 = std::sqrt(2.f);
+
+		float a0 = gamma * gamma + sqrt2 * gamma + 1.f;
+		float a1 = 2.f * gamma * gamma - 2.f;
+		float a2 = gamma * gamma - sqrt2 * gamma + 1.f;
+
+		float b0 = 1.f;
+		float b1 = - 2.f;
+		float b2 = 1.f;
+
+		a1 /= a0;
+		a2 /= a0;
+		b0 /= a0;
+		b1 /= a0;
+		b2 /= a0;
+
+		return linear_filter(std::move(stream), {a1, a2}, {b0, b1, b2});
+	}
+
+}