diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h b/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h
index 9ea3184053..74f1338dec 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h
@@ -7,87 +7,45 @@
 
 namespace DSP::HLE
 {
+struct VolumeData
+{
+  u16 volume;
+  u16 volume_delta;
+};
+
 struct PBMixer
 {
-  u16 main_left;
-  u16 main_left_delta;
-  u16 main_right;
-  u16 main_right_delta;
-
-  u16 auxA_left;
-  u16 auxA_left_delta;
-  u16 auxA_right;
-  u16 auxA_right_delta;
-
-  u16 auxB_left;
-  u16 auxB_left_delta;
-  u16 auxB_right;
-  u16 auxB_right_delta;
-
-  u16 auxB_surround;
-  u16 auxB_surround_delta;
-  u16 main_surround;
-  u16 main_surround_delta;
-  u16 auxA_surround;
-  u16 auxA_surround_delta;
+  VolumeData main_left, main_right;
+  VolumeData auxA_left, auxA_right;
+  VolumeData auxB_left, auxB_right;
+  // This somewhat strange-looking order of surround channels
+  // allows the ucode to use the 2-channel IROM function mix_two_add()
+  // when mixing (auxb_s and main_s) or (main_s and auxa_s).
+  VolumeData auxB_surround;
+  VolumeData main_surround;
+  VolumeData auxA_surround;
 };
 
 struct PBMixerWii
 {
-  // volume mixing values in .15, 0x8000 = ca. 1.0
-  u16 main_left;
-  u16 main_left_delta;
-  u16 main_right;
-  u16 main_right_delta;
-
-  u16 auxA_left;
-  u16 auxA_left_delta;
-  u16 auxA_right;
-  u16 auxA_right_delta;
-
-  u16 auxB_left;
-  u16 auxB_left_delta;
-  u16 auxB_right;
-  u16 auxB_right_delta;
-
+  VolumeData main_left, main_right;
+  VolumeData auxA_left, auxA_right;
+  VolumeData auxB_left, auxB_right;
   // Note: the following elements usage changes a little in DPL2 mode
   // TODO: implement and comment it in the mixer
-  u16 auxC_left;
-  u16 auxC_left_delta;
-  u16 auxC_right;
-  u16 auxC_right_delta;
-
-  u16 main_surround;
-  u16 main_surround_delta;
-  u16 auxA_surround;
-  u16 auxA_surround_delta;
-  u16 auxB_surround;
-  u16 auxB_surround_delta;
-  u16 auxC_surround;
-  u16 auxC_surround_delta;
+  VolumeData auxC_left, auxC_right;
+  VolumeData main_surround;
+  VolumeData auxA_surround;
+  VolumeData auxB_surround;
+  VolumeData auxC_surround;
 };
 
 struct PBMixerWM
 {
-  u16 main0;
-  u16 main0_delta;
-  u16 aux0;
-  u16 aux0_delta;
-
-  u16 main1;
-  u16 main1_delta;
-  u16 aux1;
-  u16 aux1_delta;
-
-  u16 main2;
-  u16 main2_delta;
-  u16 aux2;
-  u16 aux2_delta;
-
-  u16 main3;
-  u16 main3_delta;
-  u16 aux3;
-  u16 aux3_delta;
+  VolumeData main0, aux0;
+  VolumeData main1, aux1;
+  VolumeData main2, aux2;
+  VolumeData main3, aux3;
 };
 
 struct PBInitialTimeDelay
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h b/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h
index 298adc440e..a5fa30f165 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h
@@ -361,10 +361,10 @@ void GetInputSamples(PB_TYPE& pb, s16* samples, u16 count, const s16* coeffs)
 }
 
 // Add samples to an output buffer, with optional volume ramping.
-void MixAdd(int* out, const s16* input, u32 count, u16* pvol, s16* dpop, bool ramp)
+void MixAdd(int* out, const s16* input, u32 count, VolumeData* vd, s16* dpop, bool ramp)
 {
-  u16& volume = pvol[0];
-  u16 volume_delta = pvol[1];
+  u16& volume = vd->volume;
+  u16 volume_delta = vd->volume_delta;
 
   // If volume ramping is disabled, set volume_delta to 0. That way, the
   // mixing loop can avoid testing if volume ramping is enabled at each step,
@@ -411,8 +411,8 @@ void ProcessVoice(PB_TYPE& pb, const AXBuffers& buffers, u16 count, AXMixControl
   // Apply a global volume ramp using the volume envelope parameters.
   for (u32 i = 0; i < count; ++i)
   {
-    samples[i] = std::clamp(((s32)samples[i] * pb.vol_env.cur_volume) >> 15, -32767,
-                            32767);  // -32768 ?
+    const s32 sample = ((s32)samples[i] * pb.vol_env.cur_volume) >> 15;
+    samples[i] = std::clamp(sample, -32767, 32767);  // -32768 ?
     pb.vol_env.cur_volume += pb.vol_env.cur_volume_delta;
   }