diff --git a/Core/HW/SasAudio.cpp b/Core/HW/SasAudio.cpp
index 7cc23ea566..2f53008eb3 100644
--- a/Core/HW/SasAudio.cpp
+++ b/Core/HW/SasAudio.cpp
@@ -778,14 +778,29 @@ void SasInstance::SetWaveformEffectParams(int delay, int feedback) {
 // See http://report.ppsspp.org/logs/kind/772 for a list of games that use different types. Maybe can help us figure out
 // which is which.
 void SasInstance::ApplyWaveformEffect() {
-	// First, downsample the send buffer to 22khz. We do this naively for now.
+	// Volume max is 0x1000, while our factor is up to 0x8000. Shifting left by 3 fixes that.
+	const int volLeft = (uint16_t)(waveformEffect.leftVol << 3);
+	const int volRight = (uint16_t)(waveformEffect.rightVol << 3);
+
+	if (reverb_.GetPreset() == -1) {
+		// With no reverb selected, the ME runs a separate loop at the full 44.1khz, so the send
+		// goes straight through (tests/audio/reverb/upsample: a 22.05khz tone survives).
+		for (int i = 0; i < grainSize * 2; i += 2) {
+			sendBufferProcessed[i + 0] = clamp_s16(clamp_s16(sendBuffer[i + 0]) * volLeft >> 15);
+			sendBufferProcessed[i + 1] = clamp_s16(clamp_s16(sendBuffer[i + 1]) * volRight >> 15);
+		}
+		return;
+	}
+
+	// First, downsample the send buffer to 22khz. The ME keeps one frame of each pair, with no
+	// filter (tests/audio/reverb/upsample: a 22.05khz tone reaches the reverb as DC). It keeps the
+	// second frame; we keep the first.
 	for (int i = 0; i < grainSize / 2; i++) {
 		sendBufferDownsampled[i * 2] = clamp_s16(sendBuffer[i * 4]);
 		sendBufferDownsampled[i * 2 + 1] = clamp_s16(sendBuffer[i * 4 + 1]);
 	}
 
-	// Volume max is 0x1000, while our factor is up to 0x8000. Shifting left by 3 fixes that.
-	reverb_.ProcessReverb(sendBufferProcessed, sendBufferDownsampled, grainSize / 2, (uint16_t)(waveformEffect.leftVol << 3), (uint16_t)(waveformEffect.rightVol << 3));
+	reverb_.ProcessReverb(sendBufferProcessed, sendBufferDownsampled, grainSize / 2, volLeft, volRight);
 }
 
 void SasInstance::DoState(PointerWrap &p) {
diff --git a/Core/HW/SasReverb.cpp b/Core/HW/SasReverb.cpp
index e6ebd4011a..d3543a4f23 100644
--- a/Core/HW/SasReverb.cpp
+++ b/Core/HW/SasReverb.cpp
@@ -272,7 +272,8 @@ private:
 	int size_;
 };
 
-// The hardware upsamples the reverb's 22khz output by zero-stuffing, with no filter after it. That
+// The hardware upsamples the reverb's 22khz output by zero-stuffing, with no filter after it
+// (tests/audio/reverb/upsample: with dry off, every odd frame is exactly zero). That
 // leaves a mirror image of the whole wet signal just below 22khz, at full amplitude: it is barely
 // audible itself, but it eats the headroom of the final mix, so loud scenes clip much more (Outrun
 // 2006 while racing). We deliberately replace that with a proper interpolation filter.
@@ -330,16 +331,9 @@ void SasReverb::UpsampleWet(int16_t *out, int count) {
 }
 
 void SasReverb::ProcessReverb(int16_t *output, const int16_t *input, size_t inputSize, int volLeft, int volRight) {
-	// This means replicate the input signal in the processed buffer.
-	// Can also be used to verify that the error is in here...
+	// "Off" runs at the full rate and never gets here (see SasInstance::ApplyWaveformEffect).
 	if (preset_ == -1) {
-		// Strangely, OFF is not filled with zeroes every other.  Seems special cased.
-		for (size_t i = 0; i < inputSize; ++i) {
-			output[i * 4 + 0] = clamp_s16((int)input[i * 2 + 0] * volLeft >> 15);
-			output[i * 4 + 1] = clamp_s16((int)input[i * 2 + 1] * volRight >> 15);
-			output[i * 4 + 2] = clamp_s16((int)input[i * 2 + 0] * volLeft >> 15);
-			output[i * 4 + 3] = clamp_s16((int)input[i * 2 + 1] * volRight >> 15);
-		}
+		memset(output, 0, inputSize * 4 * sizeof(int16_t));
 		return;
 	}