diff --git a/src/science_signal/signal.py b/src/science_signal/signal.py
index 4c15847..069998b 100644
--- a/src/science_signal/signal.py
+++ b/src/science_signal/signal.py
@@ -126,7 +126,7 @@ class Signal:
         y = irfft(freq_y)
         return Signal(
             self.x[: len(y)],
-            y[: len(self.y)],
+            y[: len(self.x)],
         )
 
     def psd(self, fft_length: int = 10) -> "Signal":
@@ -146,19 +146,13 @@ class Signal:
         """
         Return the sinus of this signal
         """
-        return Signal(
-            self.x,
-            sin(self.y),
-        )
+        return Signal(self.x, sin(self.y))
 
     def sqrt(self) -> "Signal":
         """
         Return the root square of this signal
         """
-        return Signal(
-            self.x,
-            self.y ** (1 / 2),
-        )
+        return Signal(self.x, self.y ** (1 / 2))
 
     def operator_signal(
         self, other: "Signal", operator: str
@@ -174,22 +168,13 @@ class Signal:
         except ValueError:
             self, other = interpolate(self, other)
         if operator == "+":
-            return Signal(
-                self.x,
-                self.y + other.y,
-            )
+            return Signal(self.x, self.y + other.y)
         if operator == "-":
             return Signal(self.x, self.y - other.y)
         if operator == "*":
-            return Signal(
-                self.x,
-                self.y * other.y,
-            )
+            return Signal(self.x, self.y * other.y)
         if operator == "/":
-            return Signal(
-                self.x,
-                self.y / other.y,
-            )
+            return Signal(self.x, self.y / other.y)
 
         raise Exception(_("unknown operator {}").format(operator))
 
@@ -212,25 +197,13 @@ class Signal:
         except TypeError:
             pass
         if operator == "+":
-            return Signal(
-                self.x,
-                self.y + other,
-            )
+            return Signal(self.x, self.y + other)
         if operator == "-":
-            return Signal(
-                self.x,
-                self.y - other,
-            )
+            return Signal(self.x, self.y - other)
         if operator == "*":
-            return Signal(
-                self.x,
-                self.y * other,
-            )
+            return Signal(self.x, self.y * other)
         if operator == "/":
-            return Signal(
-                self.x,
-                self.y / other,
-            )
+            return Signal(self.x, self.y / other)
         raise Exception(_("unkown operator {}".format(operator)))
 
     def roperator_arraylike(
@@ -248,15 +221,9 @@ class Signal:
         except TypeError:
             pass
         if operator == "-":
-            return Signal(
-                self.x,
-                other - self.y,
-            )
+            return Signal(self.x, other - self.y)
         if operator == "/":
-            return Signal(
-                self.x,
-                other / self.y,
-            )
+            return Signal(self.x, other / self.y)
         raise Exception(_("unknown operator {}".format(operator)))
 
     def __add__(self, other: ArrayLike | "Signal") -> "Signal":
@@ -296,25 +263,16 @@ class Signal:
         return self.roperator_arraylike(other, "/")
 
     def __pow__(self, other: float | int) -> "Signal":
-        return Signal(
-            self.x,
-            self.y**other,
-        )
+        return Signal(self.x, self.y**other)
 
     def __array__(self) -> NDArray[float64]:
         return array([self.x, self.y])
 
     def __abs__(self) -> "Signal":
-        return Signal(
-            self.x,
-            abs(self.y),
-        )
+        return Signal(self.x, abs(self.y))
 
     def __neg__(self) -> "Signal":
-        return Signal(
-            self.x,
-            -self.y,
-        )
+        return Signal(self.x, -self.y)
 
     def __len__(self) -> int:
         return len(self.x)