diff --git a/LowPass.hs b/LowPass.hs
index 7ef88e1..08d712e 100644
--- a/LowPass.hs
+++ b/LowPass.hs
@@ -50,6 +50,10 @@ bandPassKernel :: Double -> (Double, Double) -> Int -> Vector Double
 bandPassKernel sr (lfc, hfc) ksize =
    invertSpectrum $ bandRejectKernel sr (lfc, hfc) ksize
 
+bandPassKernel' :: Double -> (Double, Double) -> Int -> Vector Double
+bandPassKernel' sr (lfc, hfc) ksize =
+   lowPassKernel sr hfc ksize - lowPassKernel sr lfc ksize
+
 -- convolution = integral(kernel(t-tau)*input(tau),tau)
 -- t is output vector index (j); products and summation are done with dot product (<.>)
 convolve :: Vector Double -> Vector Double -> Vector Double