diff --git a/src/modules/module-filter-chain/dsp-ops-avx.c b/src/modules/module-filter-chain/dsp-ops-avx.c
index 3a771d567..15f2a1472 100644
--- a/src/modules/module-filter-chain/dsp-ops-avx.c
+++ b/src/modules/module-filter-chain/dsp-ops-avx.c
@@ -187,6 +187,7 @@ void dsp_fft_cmuladd_avx(struct dsp_ops *ops, void *fft,
 
 	if (SPA_IS_ALIGNED(a, 32) &&
 	    SPA_IS_ALIGNED(b, 32) &&
+	    SPA_IS_ALIGNED(src, 32) &&
 	    SPA_IS_ALIGNED(dst, 32))
 		unrolled = len & ~7;
 	else
@@ -201,16 +202,16 @@ void dsp_fft_cmuladd_avx(struct dsp_ops *ops, void *fft,
 		dd[1] = _mm256_mul_pz(aa[1], bb[1]);
 		dd[0] = _mm256_mul_ps(dd[0], s);
 		dd[1] = _mm256_mul_ps(dd[1], s);
-		t[0] = _mm256_load_ps(&dst[2*i]);
-		t[1] = _mm256_load_ps(&dst[2*i+8]);
+		t[0] = _mm256_load_ps(&src[2*i]);
+		t[1] = _mm256_load_ps(&src[2*i+8]);
 		t[0] = _mm256_add_ps(t[0], dd[0]);
 		t[1] = _mm256_add_ps(t[1], dd[1]);
 		_mm256_store_ps(&dst[2*i], t[0]);
 		_mm256_store_ps(&dst[2*i+8], t[1]);
 	}
 	for (; i < len; i++) {
-		dst[2*i  ] += (a[2*i] * b[2*i  ] - a[2*i+1] * b[2*i+1]) * scale;
-		dst[2*i+1] += (a[2*i] * b[2*i+1] + a[2*i+1] * b[2*i  ]) * scale;
+		dst[2*i  ] = src[2*i  ] + (a[2*i] * b[2*i  ] - a[2*i+1] * b[2*i+1]) * scale;
+		dst[2*i+1] = src[2*i+1] + (a[2*i] * b[2*i+1] + a[2*i+1] * b[2*i  ]) * scale;
 	}
 #else
 	pffft_zconvolve_accumulate(fft, a, b, src, dst, scale);
diff --git a/src/modules/module-filter-chain/dsp-ops-c.c b/src/modules/module-filter-chain/dsp-ops-c.c
index 59814d872..16170cb30 100644
--- a/src/modules/module-filter-chain/dsp-ops-c.c
+++ b/src/modules/module-filter-chain/dsp-ops-c.c
@@ -277,7 +277,7 @@ void dsp_fft_cmul_c(struct dsp_ops *ops, void *fft,
 	const float * SPA_RESTRICT b, uint32_t len, const float scale)
 {
 #ifdef HAVE_FFTW
-	for (uint32_t i = 0; i <= len; i++) {
+	for (uint32_t i = 0; i < len; i++) {
 		dst[2*i  ] = (a[2*i] * b[2*i  ] - a[2*i+1] * b[2*i+1]) * scale;
 		dst[2*i+1] = (a[2*i] * b[2*i+1] + a[2*i+1] * b[2*i  ]) * scale;
 	}
@@ -292,9 +292,9 @@ void dsp_fft_cmuladd_c(struct dsp_ops *ops, void *fft,
 	uint32_t len, const float scale)
 {
 #ifdef HAVE_FFTW
-	for (uint32_t i = 0; i <= len; i++) {
-		dst[2*i  ] += (a[2*i] * b[2*i  ] - a[2*i+1] * b[2*i+1]) * scale;
-		dst[2*i+1] += (a[2*i] * b[2*i+1] + a[2*i+1] * b[2*i  ]) * scale;
+	for (uint32_t i = 0; i < len; i++) {
+		dst[2*i  ] = src[2*i  ] + (a[2*i] * b[2*i  ] - a[2*i+1] * b[2*i+1]) * scale;
+		dst[2*i+1] = src[2*i+1] + (a[2*i] * b[2*i+1] + a[2*i+1] * b[2*i  ]) * scale;
 	}
 #else
 	pffft_zconvolve_accumulate(fft, a, b, src, dst, scale);
diff --git a/src/modules/module-filter-chain/dsp-ops-sse.c b/src/modules/module-filter-chain/dsp-ops-sse.c
index 0f4dea9e2..9e7d7b753 100644
--- a/src/modules/module-filter-chain/dsp-ops-sse.c
+++ b/src/modules/module-filter-chain/dsp-ops-sse.c
@@ -608,6 +608,7 @@ void dsp_fft_cmuladd_sse(struct dsp_ops *ops, void *fft,
 
 	if (SPA_IS_ALIGNED(a, 16) &&
 	    SPA_IS_ALIGNED(b, 16) &&
+	    SPA_IS_ALIGNED(src, 16) &&
 	    SPA_IS_ALIGNED(dst, 16))
 		unrolled = len & ~3;
 	else
@@ -621,16 +622,16 @@ void dsp_fft_cmuladd_sse(struct dsp_ops *ops, void *fft,
 		_mm_mul_pz(aa, bb, dd);
 		dd[0] = _mm_mul_ps(dd[0], s);
 		dd[1] = _mm_mul_ps(dd[1], s);
-		t[0] = _mm_load_ps(&dst[2*i]);
-		t[1] = _mm_load_ps(&dst[2*i+4]);
+		t[0] = _mm_load_ps(&src[2*i]);
+		t[1] = _mm_load_ps(&src[2*i+4]);
 		t[0] = _mm_add_ps(t[0], dd[0]);
 		t[1] = _mm_add_ps(t[1], dd[1]);
 		_mm_store_ps(&dst[2*i], t[0]);
 		_mm_store_ps(&dst[2*i+4], t[1]);
 	}
 	for (; i < len; i++) {
-		dst[2*i  ] += (a[2*i] * b[2*i  ] - a[2*i+1] * b[2*i+1]) * scale;
-		dst[2*i+1] += (a[2*i] * b[2*i+1] + a[2*i+1] * b[2*i  ]) * scale;
+		dst[2*i  ] = src[2*i  ] + (a[2*i] * b[2*i  ] - a[2*i+1] * b[2*i+1]) * scale;
+		dst[2*i+1] = src[2*i+1] + (a[2*i] * b[2*i+1] + a[2*i+1] * b[2*i  ]) * scale;
 	}
 #else
 	pffft_zconvolve_accumulate(fft, a, b, src, dst, scale);