From 2908a8b56f94d87400a117ad75e2ffd9f3b2209a Mon Sep 17 00:00:00 2001
From: Geraint <luffgd@gmail.com>
Date: Sun, 6 Jul 2025 10:08:14 +0100
Subject: [PATCH] Stereo energy compensation

---
 chorus.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/chorus.h b/chorus.h
index 5b9bca9..6cbf5d1 100644
--- a/chorus.h
+++ b/chorus.h
@@ -97,8 +97,14 @@ struct ChorusSTFX : public BaseEffect {
 		std::array<Sample, 6> multiIn, multiOut;
 		std::array<Sample, 6> delaySamples;
 		
-		auto dry = block.smooth(mix, [](double m){return 1 - m*m;});
-		auto wet = block.smooth(mix, [](double m){return m*(2 - m)/std::sqrt(Sample(6));});
+		auto wetDryFn = [](double mix, double width, bool isWet){
+			// Equal-power wet/dry fade
+			double m = isWet ? std::sin(M_PI*mix/2) : std::cos(M_PI*mix/2);
+			// Compensate for extra energy from stereo
+			return m/std::sqrt(6*(1 + width*width/2));
+		};
+		auto dry = block.smooth(wetDryFn(mix.from(), stereo.from(), false), wetDryFn(mix.to(), stereo.to(), false));
+		auto wet = block.smooth(wetDryFn(mix.from(), stereo.from(), true), wetDryFn(mix.to(), stereo.to(), true));
 		bool notMono = (config.outputChannels > 1);
 		auto width = block.smooth(stereo);