diff --git a/lib/filter/src/tb_fir_parallel.vhd b/lib/filter/src/tb_fir_parallel.vhd
index f50f411..511f9a0 100644
--- a/lib/filter/src/tb_fir_parallel.vhd
+++ b/lib/filter/src/tb_fir_parallel.vhd
@@ -96,7 +96,7 @@ ARCHITECTURE behavior OF tb_fir_parallel IS
 	SIGNAL fileout_enable   : std_logic := '1';
 	
 	-- Test coefficients
-	SIGNAL coeff_in : sfixed_array_t(0 to ntaps-1, shi(nbits_stages, nbits_stages_frac) downto slo(nbits_stages, nbits_stages_frac)) := to_sfixed_array(FilterCoef_Lowpass(ntaps, 0.125, 0.125), nbits_stages, nbits_stages_frac);
+	SIGNAL coeff_in : sfixed_array_t(0 to ntaps-1, shi(nbits_stages, nbits_stages_frac) downto slo(nbits_stages, nbits_stages_frac)) := to_sfixed_array(FilterCoef_Lowpass(ntaps, 0.125, 1.0), nbits_stages, nbits_stages_frac);
 	
 	SIGNAL xi, yo : real := 0.0;