diff --git a/lib_enc/ivas_stereo_mdct_core_enc_fx.c b/lib_enc/ivas_stereo_mdct_core_enc_fx.c
index 804bcff5c19bed490ed68746d8282f39a68e2127..3becb30d93c7b13147a5f01ab923ff9f58bc708c 100644
--- a/lib_enc/ivas_stereo_mdct_core_enc_fx.c
+++ b/lib_enc/ivas_stereo_mdct_core_enc_fx.c
@@ -363,26 +363,24 @@ void stereo_mdct_core_enc_fx(
         move16();
         FOR( ch = 0; ch < CPE_CHANNELS; ch++ )
         {
-            IF( EQ_16( sts[ch]->hTcxEnc->tcxMode, TCX_20 ) )
-            {
-                length = sts[ch]->hTcxEnc->L_frameTCX;
-                move16();
-            }
-            ELSE
+            length = sts[ch]->hTcxEnc->L_frameTCX;
+            move16();
+            if ( NE_16( sts[ch]->hTcxEnc->tcxMode, TCX_20 ) )
             {
                 length = shr( sts[ch]->hTcxEnc->L_frameTCX, 1 );
             }
-            FOR( k = 0; k <= ( ( sts[ch]->core == TCX_20_CORE ) ? 1 : NB_DIV ) - 1; k++ )
+
+            hdrm_min = s_min( hdrm_min, L_norm_arr( sts[ch]->hTcxEnc->spectrum_fx[0], length ) );
+            hdrm_min = s_min( hdrm_min, L_norm_arr( mdst_spectrum_fx[ch][0], length ) );
+
+            IF( NE_16( sts[ch]->hTcxEnc->tcxMode, TCX_20 ) )
             {
-                hdrm_min = s_min( hdrm_min, L_norm_arr( sts[ch]->hTcxEnc->spectrum_fx[k], length ) );
-                hdrm_min = s_min( hdrm_min, L_norm_arr( mdst_spectrum_fx[ch][k], length ) );
+                hdrm_min = s_min( hdrm_min, L_norm_arr( sts[ch]->hTcxEnc->spectrum_fx[1], length ) );
+                hdrm_min = s_min( hdrm_min, L_norm_arr( mdst_spectrum_fx[ch][1], length ) );
             }
         }
 
-        IF( hdrm_min != 0 )
-        {
-            q_spec = sub( add( hdrm_min, q_spec ), 1 ); /*1 guard bit to avoid over-flows*/
-        }
+        q_spec = sub( add( hdrm_min, q_spec ), 2 ); /* 2 guard bits to avoid over-flows (1 for stereo_coder_tcx_fx and other for power spectrum calculation )*/
 
         FOR( ch = 0; ch < CPE_CHANNELS; ch++ )
         {