diff --git a/modules/cmake/WarningFlags.cmake b/modules/cmake/WarningFlags.cmake
index b657f7e6..e049e6d8 100644
--- a/modules/cmake/WarningFlags.cmake
+++ b/modules/cmake/WarningFlags.cmake
@@ -43,6 +43,7 @@ if(WIN32)
             -Wno-implicit-int-float-conversion
             -Wno-implicit-const-int-float-conversion
             -Wno-unsafe-buffer-usage
+            -Wno-unknown-warning-option
             -Wno-header-hygiene
         )
     elseif((CMAKE_CXX_COMPILER_ID STREQUAL "MSVC") OR (CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC"))
diff --git a/src/processors/other/poly_octave/DelayPitchShifter.h b/src/processors/other/poly_octave/DelayPitchShifter.h
new file mode 100644
index 00000000..9de03f80
--- /dev/null
+++ b/src/processors/other/poly_octave/DelayPitchShifter.h
@@ -0,0 +1,89 @@
+#pragma once
+
+#include <pch.h>
+
+namespace pitch_shift
+{
+template <typename T>
+struct Delay
+{
+    std::vector<T> delay_buffer {};
+    size_t write_pointer = 0;
+    T read_pointer {};
+    size_t N_int = 0;
+    T N {};
+    T phase_offset_01 {};
+    T read_pointer_increment = (T) 1;
+
+    void prepare (double sample_rate, T initial_phase_offset_01 = {})
+    {
+        N_int = static_cast<size_t> (sample_rate * 0.075);
+        delay_buffer.resize (2 * N_int, T {});
+        N = static_cast<T> (N_int);
+        write_pointer = 0;
+
+        phase_offset_01 = initial_phase_offset_01;
+        read_pointer = N * phase_offset_01;
+    }
+
+    void reset()
+    {
+        std::fill (delay_buffer.begin(), delay_buffer.end(), T {});
+        write_pointer = 0;
+        read_pointer = N * phase_offset_01;
+    }
+
+    T get_phase_01() const noexcept
+    {
+        const auto offset = static_cast<T> (write_pointer);
+        const auto wrapped_offset = read_pointer >= offset ? offset : offset - N;
+        return (read_pointer - wrapped_offset) / N;
+    }
+
+    T process_sample (T x) noexcept
+    {
+        delay_buffer[write_pointer] = x;
+        delay_buffer[write_pointer + N_int] = x;
+
+        const auto rp_int = static_cast<size_t> (read_pointer);
+        const auto alpha = read_pointer - static_cast<T> (rp_int);
+        const auto y = ((T) 1 - alpha) * delay_buffer[rp_int] + alpha * delay_buffer[rp_int + 1];
+
+        read_pointer = std::fmod (read_pointer + read_pointer_increment, N);
+        write_pointer = (write_pointer + 1) % N_int;
+
+        const auto amplitude_mod = (T) 0.5 * ((T) 1 - math_approx::cos<5> (juce::MathConstants<T>::twoPi * get_phase_01()));
+        return y * amplitude_mod;
+    }
+};
+
+template <typename T>
+struct Processor
+{
+    Delay<T> d_0 {};
+    Delay<T> d_half {};
+
+    void prepare (double sample_rate)
+    {
+        d_0.prepare (sample_rate);
+        d_half.prepare (sample_rate, (T) 0.5);
+    }
+
+    void reset()
+    {
+        d_0.reset();
+        d_half.reset();
+    }
+
+    void set_pitch_factor (T shift_factor)
+    {
+        d_0.read_pointer_increment = shift_factor;
+        d_half.read_pointer_increment = shift_factor;
+    }
+
+    T process_sample (T x) noexcept
+    {
+        return d_0.process_sample (x) + d_half.process_sample (x);
+    }
+};
+} // namespace pitch_shift
diff --git a/src/processors/other/poly_octave/PolyOctave.cpp b/src/processors/other/poly_octave/PolyOctave.cpp
index d16b0a6e..99c9ab11 100644
--- a/src/processors/other/poly_octave/PolyOctave.cpp
+++ b/src/processors/other/poly_octave/PolyOctave.cpp
@@ -7,6 +7,7 @@ namespace PolyOctaveTags
 const String dryTag = "dry";
 const String upOctaveTag = "up_octave";
 const String up2OctaveTag = "up2_octave";
+const String downOctaveTag = "down_octave";
 } // namespace PolyOctaveTags
 
 PolyOctave::PolyOctave (UndoManager* um)
@@ -28,6 +29,7 @@ PolyOctave::PolyOctave (UndoManager* um)
             return 2 * x * x;
         };
     };
+    setupGainParam (PolyOctaveTags::downOctaveTag, downOctaveGain);
     setupGainParam (PolyOctaveTags::dryTag, dryGain);
     setupGainParam (PolyOctaveTags::upOctaveTag, upOctaveGain);
     setupGainParam (PolyOctaveTags::up2OctaveTag, up2OctaveGain);
@@ -43,6 +45,7 @@ ParamLayout PolyOctave::createParameterLayout()
     using namespace ParameterHelpers;
     auto params = createBaseParams();
 
+    createPercentParameter (params, PolyOctaveTags::downOctaveTag, "-1 Oct", 0.0f);
     createPercentParameter (params, PolyOctaveTags::dryTag, "+0 Oct", 0.5f);
     createPercentParameter (params, PolyOctaveTags::upOctaveTag, "+1 Oct", 0.0f);
     createPercentParameter (params, PolyOctaveTags::up2OctaveTag, "+2 Oct", 0.0f);
@@ -55,14 +58,22 @@ void PolyOctave::prepare (double sampleRate, int samplesPerBlock)
     dryGain.prepare (sampleRate, samplesPerBlock);
     up2OctaveGain.prepare (sampleRate, samplesPerBlock);
     upOctaveGain.prepare (sampleRate, samplesPerBlock);
+    downOctaveGain.prepare (sampleRate, samplesPerBlock);
 
     doubleBuffer.setMaxSize (2, samplesPerBlock);
     up2OctaveBuffer.setMaxSize (2, static_cast<int> (ComplexERBFilterBank::float_2::size) * samplesPerBlock); // allocate extra space for SIMD
     upOctaveBuffer.setMaxSize (2, static_cast<int> (ComplexERBFilterBank::float_2::size) * samplesPerBlock); // allocate extra space for SIMD
+    downOctaveBuffer.setMaxSize (2, samplesPerBlock);
 
     FilterBankHelpers::designFilterBank (octaveUpFilterBank, 2.0, 5.0, 6.0, sampleRate);
     FilterBankHelpers::designFilterBank (octaveUp2FilterBank, 3.0, 7.0, 4.0, sampleRate);
 
+    for (auto& shifter : downOctavePitchShifters)
+    {
+        shifter.prepare (sampleRate);
+        shifter.set_pitch_factor (0.5);
+    }
+
     for (auto& busDCBlocker : dcBlocker)
     {
         busDCBlocker.prepare (2);
@@ -72,6 +83,7 @@ void PolyOctave::prepare (double sampleRate, int samplesPerBlock)
     mixOutBuffer.setSize (2, samplesPerBlock);
     up1OutBuffer.setSize (2, samplesPerBlock);
     up2OutBuffer.setSize (2, samplesPerBlock);
+    down1OutBuffer.setSize (2, samplesPerBlock);
 }
 
 void PolyOctave::processAudio (AudioBuffer<float>& buffer)
@@ -82,9 +94,18 @@ void PolyOctave::processAudio (AudioBuffer<float>& buffer)
     doubleBuffer.setCurrentSize (numChannels, numSamples);
     upOctaveBuffer.setCurrentSize (numChannels, numSamples);
     up2OctaveBuffer.setCurrentSize (numChannels, numSamples);
+    downOctaveBuffer.setCurrentSize (numChannels, numSamples);
 
     chowdsp::BufferMath::copyBufferData (buffer, doubleBuffer);
 
+    // "down" processing
+    for (auto [ch, data_in, data_out] : chowdsp::buffer_iters::zip_channels (std::as_const (doubleBuffer), downOctaveBuffer))
+    {
+        for (auto [x, y] : chowdsp::zip (data_in, data_out))
+            y = downOctavePitchShifters[(size_t) ch].process_sample (x);
+    }
+
+    // "up" processing
     using float_2 = ComplexERBFilterBank::float_2;
     for (int ch = 0; ch < numChannels; ++ch)
     {
@@ -165,26 +186,35 @@ void PolyOctave::processAudio (AudioBuffer<float>& buffer)
     up2OctaveGain.process (numSamples);
     chowdsp::BufferMath::applyGainSmoothedBuffer (up2OctaveBuffer, up2OctaveGain);
 
+    chowdsp::BufferMath::applyGain (downOctaveBuffer, juce::Decibels::decibelsToGain (3.0f));
+    downOctaveGain.process (numSamples);
+    chowdsp::BufferMath::applyGainSmoothedBuffer (downOctaveBuffer, downOctaveGain);
+
     dryGain.process (numSamples);
     chowdsp::BufferMath::applyGainSmoothedBuffer (doubleBuffer, dryGain);
     chowdsp::BufferMath::addBufferData (up2OctaveBuffer, doubleBuffer);
     chowdsp::BufferMath::addBufferData (upOctaveBuffer, doubleBuffer);
+    chowdsp::BufferMath::addBufferData (downOctaveBuffer, doubleBuffer);
 
     mixOutBuffer.setSize (numChannels, numSamples, false, false, true);
     up1OutBuffer.setSize (numChannels, numSamples, false, false, true);
     up2OutBuffer.setSize (numChannels, numSamples, false, false, true);
+    down1OutBuffer.setSize (numChannels, numSamples, false, false, true);
 
     chowdsp::BufferMath::copyBufferData (doubleBuffer, mixOutBuffer);
     chowdsp::BufferMath::copyBufferData (upOctaveBuffer, up1OutBuffer);
     chowdsp::BufferMath::copyBufferData (up2OctaveBuffer, up2OutBuffer);
+    chowdsp::BufferMath::copyBufferData (downOctaveBuffer, down1OutBuffer);
 
     dcBlocker[MixOutput].processBlock (mixOutBuffer);
     dcBlocker[Up1Output].processBlock (up1OutBuffer);
     dcBlocker[Up2Output].processBlock (up2OutBuffer);
+    dcBlocker[Down1Output].processBlock (down1OutBuffer);
 
     outputBuffers.getReference (MixOutput) = &mixOutBuffer;
     outputBuffers.getReference (Up1Output) = &up1OutBuffer;
     outputBuffers.getReference (Up2Output) = &up2OutBuffer;
+    outputBuffers.getReference (Down1Output) = &down1OutBuffer;
 }
 
 void PolyOctave::processAudioBypassed (AudioBuffer<float>& buffer)
@@ -194,14 +224,17 @@ void PolyOctave::processAudioBypassed (AudioBuffer<float>& buffer)
     mixOutBuffer.setSize (buffer.getNumChannels(), numSamples, false, false, true);
     up1OutBuffer.setSize (1, numSamples, false, false, true);
     up2OutBuffer.setSize (1, numSamples, false, false, true);
+    down1OutBuffer.setSize (1, numSamples, false, false, true);
 
     chowdsp::BufferMath::copyBufferData (buffer, mixOutBuffer);
     up1OutBuffer.clear();
     up2OutBuffer.clear();
+    down1OutBuffer.clear();
 
     outputBuffers.getReference (MixOutput) = &mixOutBuffer;
     outputBuffers.getReference (Up1Output) = &up1OutBuffer;
     outputBuffers.getReference (Up2Output) = &up2OutBuffer;
+    outputBuffers.getReference (Down1Output) = &down1OutBuffer;
 }
 
 String PolyOctave::getTooltipForPort (int portIndex, bool isInput)
@@ -216,6 +249,8 @@ String PolyOctave::getTooltipForPort (int portIndex, bool isInput)
                 return "+1 Octave Output";
             case OutputPort::Up2Output:
                 return "+2 Octave Output";
+            case OutputPort::Down1Output:
+                return "-1 Octave Output";
         }
     }
 
diff --git a/src/processors/other/poly_octave/PolyOctave.h b/src/processors/other/poly_octave/PolyOctave.h
index 9f2230b9..08ebf96c 100644
--- a/src/processors/other/poly_octave/PolyOctave.h
+++ b/src/processors/other/poly_octave/PolyOctave.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "DelayPitchShifter.h"
 #include "processors/BaseProcessor.h"
 
 class PolyOctave : public BaseProcessor
@@ -26,8 +27,9 @@ class PolyOctave : public BaseProcessor
     enum OutputPort
     {
         MixOutput,
-        Up1Output,
         Up2Output,
+        Up1Output,
+        Down1Output,
     };
 
     static constexpr auto numOutputs = (int) magic_enum::enum_count<OutputPort>();
@@ -36,19 +38,23 @@ class PolyOctave : public BaseProcessor
     chowdsp::SmoothedBufferValue<double> dryGain {};
     chowdsp::SmoothedBufferValue<double> upOctaveGain {};
     chowdsp::SmoothedBufferValue<double> up2OctaveGain {};
+    chowdsp::SmoothedBufferValue<double> downOctaveGain {};
 
     chowdsp::Buffer<double> doubleBuffer;
     chowdsp::Buffer<double> upOctaveBuffer;
     chowdsp::Buffer<double> up2OctaveBuffer;
+    chowdsp::Buffer<double> downOctaveBuffer;
 
     std::array<ComplexERBFilterBank, 2> octaveUpFilterBank;
     std::array<ComplexERBFilterBank, 2> octaveUp2FilterBank;
+    std::array<pitch_shift::Processor<double>, 2> downOctavePitchShifters;
 
     std::array<chowdsp::FirstOrderHPF<float>, (size_t) numOutputs> dcBlocker;
 
     juce::AudioBuffer<float> mixOutBuffer;
     juce::AudioBuffer<float> up1OutBuffer;
     juce::AudioBuffer<float> up2OutBuffer;
+    juce::AudioBuffer<float> down1OutBuffer;
 
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (PolyOctave)
 };