diff --git a/src/source/blt.rs b/src/source/blt.rs
index c5068686..d32b6310 100644
--- a/src/source/blt.rs
+++ b/src/source/blt.rs
@@ -6,7 +6,37 @@ use crate::Source;
 // Implemented following http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
 
 /// Internal function that builds a `BltFilter` object.
-pub fn low_pass<I>(input: I, freq: u32, q: f32) -> BltFilter<I>
+pub fn low_pass<I>(input: I, freq: u32) -> BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    BltFilter {
+        input,
+        formula: BltFormula::LowPass { freq, q: 0.5 },
+        applier: None,
+        x_n1: 0.0,
+        x_n2: 0.0,
+        y_n1: 0.0,
+        y_n2: 0.0,
+    }
+}
+
+pub fn high_pass<I>(input: I, freq: u32) -> BltFilter<I>
+where
+    I: Source<Item = f32>,
+{
+    BltFilter {
+        input,
+        formula: BltFormula::HighPass { freq, q: 0.5 },
+        applier: None,
+        x_n1: 0.0,
+        x_n2: 0.0,
+        y_n1: 0.0,
+        y_n2: 0.0,
+    }
+}
+
+pub fn low_pass_with_q<I>(input: I, freq: u32, q: f32) -> BltFilter<I>
 where
     I: Source<Item = f32>,
 {
@@ -21,7 +51,7 @@ where
     }
 }
 
-pub fn high_pass<I>(input: I, freq: u32, q: f32) -> BltFilter<I>
+pub fn high_pass_with_q<I>(input: I, freq: u32, q: f32) -> BltFilter<I>
 where
     I: Source<Item = f32>,
 {
@@ -49,13 +79,24 @@ pub struct BltFilter<I> {
 
 impl<I> BltFilter<I> {
     /// Modifies this filter so that it becomes a low-pass filter.
-    pub fn to_low_pass(&mut self, freq: u32, q: f32) {
+    pub fn to_low_pass(&mut self, freq: u32) {
+        self.formula = BltFormula::LowPass { freq, q: 0.5 };
+        self.applier = None;
+    }
+
+    /// Modifies this filter so that it becomes a high-pass filter
+    pub fn to_high_pass(&mut self, freq: u32) {
+        self.formula = BltFormula::HighPass { freq, q: 0.5 };
+        self.applier = None;
+    }
+
+    pub fn to_low_pass_with_q(&mut self, freq: u32, q: f32) {
         self.formula = BltFormula::LowPass { freq, q };
         self.applier = None;
     }
 
     /// Modifies this filter so that it becomes a high-pass filter
-    pub fn to_high_pass(&mut self, freq: u32, q: f32) {
+    pub fn to_high_pass_with_q(&mut self, freq: u32, q: f32) {
         self.formula = BltFormula::HighPass { freq, q };
         self.applier = None;
     }
diff --git a/src/source/mod.rs b/src/source/mod.rs
index dccd4fd5..318cf767 100644
--- a/src/source/mod.rs
+++ b/src/source/mod.rs
@@ -335,21 +335,38 @@ where
     /// Applies a low-pass filter to the source.
     /// **Warning**: Probably buggy.
     #[inline]
-    fn low_pass(self, freq: u32, q: f32) -> BltFilter<Self>
+    fn low_pass(self, freq: u32) -> BltFilter<Self>
     where
         Self: Sized,
         Self: Source<Item = f32>,
     {
-        blt::low_pass(self, freq, q)
+        blt::low_pass(self, freq)
     }
 
     #[inline]
-    fn high_pass(self, freq: u32, q: f32) -> BltFilter<Self>
+    fn high_pass(self, freq: u32) -> BltFilter<Self>
     where
         Self: Sized,
         Self: Source<Item = f32>,
     {
-        blt::high_pass(self, freq, q)
+        blt::high_pass(self, freq)
+    }
+
+    fn low_pass_with_q(self, freq: u32, q: f32) -> BltFilter<Self>
+    where
+        Self: Sized,
+        Self: Source<Item = f32>,
+    {
+        blt::low_pass_with_q(self, freq, q)
+    }
+
+    #[inline]
+    fn high_pass_with_q(self, freq: u32, q: f32) -> BltFilter<Self>
+    where
+        Self: Sized,
+        Self: Source<Item = f32>,
+    {
+        blt::high_pass_with_q(self, freq, q)
     }
 }