diff --git a/libraries/dsp/verify_pfb/tb_verify_pfb_wg.vhd b/libraries/dsp/verify_pfb/tb_verify_pfb_wg.vhd
index d8ea9478d0881cacbb03fcc97b2193437f169e54..41d547963654ac7de8b143a745b68ef723ab8ce2 100644
--- a/libraries/dsp/verify_pfb/tb_verify_pfb_wg.vhd
+++ b/libraries/dsp/verify_pfb/tb_verify_pfb_wg.vhd
@@ -146,7 +146,7 @@ ENTITY tb_verify_pfb_wg IS
     --g_fil_coefs_file_prefix : STRING := "data/run_pfir_coeff_m_fircls1_16taps_1024points_18b_1wb";   -- g_fil_coef_dat_w = 18 bit
     g_fil_coef_dat_w        : NATURAL := 16;   -- = 16, data width of the FIR coefficients
     --g_fil_coef_dat_w        : NATURAL := 18;   -- = 16, data width of the FIR coefficients
-    g_fil_backoff_w         : NATURAL := 0;    -- = 0, number of bits for input backoff to avoid output overflow
+    g_fil_backoff_w         : NATURAL := 1;    -- = 0, number of bits for input backoff to avoid output overflow
     g_fil_in_dat_w          : NATURAL := 14;   -- = W_adc, number of input bits
     
     g_internal_dat_w        : NATURAL := 0;   -- = number of bits between fil and fft, use 0 to use maximum default:
@@ -239,8 +239,9 @@ ARCHITECTURE tb OF tb_verify_pfb_wg IS
   CONSTANT c_nof_channels            : NATURAL := 2**c_wpfb.nof_chan;       -- = 2**0 = 1, so no time multiplexing of inputs
   CONSTANT c_nof_sync                : NATURAL := 5;                        -- nof sync intervals to simulate
   
-  CONSTANT c_pfb_sub_scaling         : REAL := 2.0**REAL(g_fft_out_dat_w + g_fft_out_gain_w - g_fil_in_dat_w - 1);  -- expected subband amplitude gain relative to input WG amplitude
-                                                                                                                    -- -1 for divide by 2 in two real input separate (Ampl --> Ampl/2)
+  -- Expected subband amplitude gain relative to input WG amplitude -1 for divide by 2 in two real input separate (Ampl --> Ampl/2)
+  CONSTANT c_pfb_sub_scaling         : REAL := 2.0**REAL((g_fft_out_dat_w + g_fft_out_gain_w) - (g_fil_in_dat_w + g_fil_backoff_w) - 1);
+
   -- Subband at WG frequency
   CONSTANT c_bin_a                   : NATURAL := NATURAL(FLOOR(g_subband_index_a));
   CONSTANT c_bin_a_frac_en           : BOOLEAN := g_subband_index_a > REAL(c_bin_a);