diff --git a/core/src/backend/audio.rs b/core/src/backend/audio.rs
index 883fa2ad7..aca7ad192 100644
--- a/core/src/backend/audio.rs
+++ b/core/src/backend/audio.rs
@@ -580,21 +580,12 @@ impl From<display_object::SoundTransform> for SoundTransform {
     fn from(other: display_object::SoundTransform) -> Self {
         const SCALE: f32 = display_object::SoundTransform::MAX_VOLUME.pow(2) as f32;
 
-        // It seems like Flash stores sound transform values in 30-bit unsigned integers:
-        // * Negative values are equivalent to their absolute value.
-        // * Specifically, 0x40000000, -0x40000000 and -0x80000000 are equivalent to zero.
-        // * The volume multiplication wraps around at `u32::MAX`.
-        let left_to_left = (other.left_to_left << 2) >> 2;
-        let left_to_right = (other.left_to_right << 2) >> 2;
-        let right_to_left = (other.right_to_left << 2) >> 2;
-        let right_to_right = (other.right_to_right << 2) >> 2;
-        let volume = (other.volume << 2) >> 2;
-
+        // The volume multiplication wraps around at `u32::MAX`.
         Self {
-            left_to_left: left_to_left.wrapping_mul(volume) as f32 / SCALE,
-            left_to_right: left_to_right.wrapping_mul(volume) as f32 / SCALE,
-            right_to_left: right_to_left.wrapping_mul(volume) as f32 / SCALE,
-            right_to_right: right_to_right.wrapping_mul(volume) as f32 / SCALE,
+            left_to_left: other.left_to_left.wrapping_mul(other.volume) as f32 / SCALE,
+            left_to_right: other.left_to_right.wrapping_mul(other.volume) as f32 / SCALE,
+            right_to_left: other.right_to_left.wrapping_mul(other.volume) as f32 / SCALE,
+            right_to_right: other.right_to_right.wrapping_mul(other.volume) as f32 / SCALE,
         }
     }
 }
diff --git a/core/src/display_object.rs b/core/src/display_object.rs
index e1a0d5d99..052c757a1 100644
--- a/core/src/display_object.rs
+++ b/core/src/display_object.rs
@@ -1554,11 +1554,17 @@ impl SoundTransform {
 
     /// Applies another SoundTransform on top of this SoundTransform.
     pub fn concat(&mut self, other: &SoundTransform) {
+        const MAX_VOLUME: i64 = SoundTransform::MAX_VOLUME as i64;
+
+        // It seems like Flash masks the results below to 30-bit integers:
+        // * Negative values are equivalent to their absolute value (their sign bit is unset).
+        // * Specifically, 0x40000000, -0x40000000 and -0x80000000 are equivalent to zero.
+        const MASK: i32 = (1 << 30) - 1;
+
+        self.volume = (i64::from(self.volume) * i64::from(other.volume) / MAX_VOLUME) as i32 & MASK;
+
         // This is a 2x2 matrix multiply between the transforms.
         // Done with integer math to match Flash behavior.
-        const MAX_VOLUME: i64 = SoundTransform::MAX_VOLUME as i64;
-        self.volume = (i64::from(self.volume) * i64::from(other.volume) / MAX_VOLUME) as i32;
-
         let ll0: i64 = self.left_to_left.into();
         let lr0: i64 = self.left_to_right.into();
         let rl0: i64 = self.right_to_left.into();
@@ -1567,10 +1573,10 @@ impl SoundTransform {
         let lr1: i64 = other.left_to_right.into();
         let rl1: i64 = other.right_to_left.into();
         let rr1: i64 = other.right_to_right.into();
-        self.left_to_left = ((ll0 * ll1 + rl0 * lr1) / MAX_VOLUME) as i32;
-        self.left_to_right = ((lr0 * ll1 + rr0 * lr1) / MAX_VOLUME) as i32;
-        self.right_to_left = ((ll0 * rl1 + rl0 * rr1) / MAX_VOLUME) as i32;
-        self.right_to_right = ((lr0 * rl1 + rr0 * rr1) / MAX_VOLUME) as i32;
+        self.left_to_left = ((ll0 * ll1 + rl0 * lr1) / MAX_VOLUME) as i32 & MASK;
+        self.left_to_right = ((lr0 * ll1 + rr0 * lr1) / MAX_VOLUME) as i32 & MASK;
+        self.right_to_left = ((ll0 * rl1 + rl0 * rr1) / MAX_VOLUME) as i32 & MASK;
+        self.right_to_right = ((lr0 * rl1 + rr0 * rr1) / MAX_VOLUME) as i32 & MASK;
     }
 
     /// Returns the pan of this transform.