diff --git a/dsp/src/lockin.rs b/dsp/src/lockin.rs
index d78c01b..75c7b97 100644
--- a/dsp/src/lockin.rs
+++ b/dsp/src/lockin.rs
@@ -12,7 +12,7 @@ impl Lockin {
     pub fn new(k: u8) -> Self {
         let lp = Lowpass::default();
         Self {
-            state: [lp.clone(), lp.clone()],
+            state: [lp.clone(), lp],
             k,
         }
     }
diff --git a/dsp/src/lowpass.rs b/dsp/src/lowpass.rs
index e3a1353..b85e2ed 100644
--- a/dsp/src/lowpass.rs
+++ b/dsp/src/lowpass.rs
@@ -27,7 +27,7 @@ impl<N: ArrayLength<i32>> Lowpass<N> {
         let mut x1 = self.xy[0];
         self.xy[0] = x;
         for y1 in self.xy[1..].iter_mut() {
-            x0 = *y1 + (((x0 >> 1) + (x1 >> 1) - *y1 + (1 << k - 1)) >> k);
+            x0 = *y1 + (((x0 >> 1) + (x1 >> 1) - *y1 + (1 << (k - 1))) >> k);
             x1 = *y1;
             *y1 = x0;
         }