diff --git a/lib_com/options.h b/lib_com/options.h
index 4a5a53c9875ce1551eab189919b257c3f28c64e9..5257a5d6a276d9489f951ea7a5dbbf28aa138ef1 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -166,6 +166,7 @@
 #define FIX_1741_REVERB_TIMES_Q_FORMAT                  /* Philips: reverberation times in Q26 format instead of Q31 */
 #define FIX_1831_REVERB_REGRESSION                      /* Philips: fixes reverb regression issues  */
 
+#define FIX_1835_REVERB_ACTIVATION                      /* FhG: Modified reverberation activation logic and corrected factEQ calculation */
 /* #################### End BASOP porting switches ############################ */
 
 #endif
diff --git a/lib_dec/ivas_binRenderer_internal_fx.c b/lib_dec/ivas_binRenderer_internal_fx.c
index 68886c1baac85e6bed86c46fd0b0df026c325b63..d241cd145d313fe5c5ba8794c4dfc6e7406daa37 100644
--- a/lib_dec/ivas_binRenderer_internal_fx.c
+++ b/lib_dec/ivas_binRenderer_internal_fx.c
@@ -1012,7 +1012,6 @@ static void ivas_binaural_obtain_DMX_fx(
                         move32();
                         imagDMX[chOutIdx][k][bandIdx] = L_add( imagDMX[chOutIdx][k][bandIdx], temp2_fx ); // Q_in
                         move32();
-
                         P_in_fx[bandIdx] = L_add( P_in_fx[bandIdx], L_add( Mpy_32_32( temp1_fx, temp1_fx ), Mpy_32_32( temp2_fx, temp2_fx ) ) ); // Q31-2*Q_in
                         move32();
                     }
@@ -1040,7 +1039,11 @@ static void ivas_binaural_obtain_DMX_fx(
                 ELSE
                 {
                     Word16 div = divide3232( P_in_fx[bandIdx], P_out_fx );
+#ifdef FIX_1835_REVERB_ACTIVATION
+                    Word16 exp = 0; // divide3232 returns Q15 + following Q16 shift
+#else
                     Word16 exp = norm_l( div );
+#endif
                     factEQ_fx = Sqrt32( L_shl( div, Q16 ), &exp );
                     factEQ_fx = L_shl( factEQ_fx, sub( exp, 1 ) ); // Q30
                 }
@@ -1405,7 +1408,11 @@ ivas_error ivas_binRenderer_open_fx(
 
     /* Allocate memories needed for reverb module */
     test();
+#ifdef FIX_1835_REVERB_ACTIVATION
+    IF( EQ_32( st_ivas->renderer_type, RENDERER_BINAURAL_FASTCONV_ROOM ) || ( EQ_32( st_ivas->renderer_type, RENDERER_BINAURAL_FASTCONV ) && EQ_32( st_ivas->hOutSetup.output_config, IVAS_AUDIO_CONFIG_BINAURAL_ROOM_REVERB ) ) )
+#else
     IF( ( EQ_32( st_ivas->renderer_type, RENDERER_BINAURAL_FASTCONV_ROOM ) || EQ_32( st_ivas->renderer_type, RENDERER_BINAURAL_FASTCONV ) ) && EQ_32( st_ivas->hOutSetup.output_config, IVAS_AUDIO_CONFIG_BINAURAL_ROOM_REVERB ) )
+#endif
     {
         IF( NE_32( ( error = ivas_binaural_reverb_init( &( hBinRenderer->hReverb ), st_ivas->hHrtfStatistics, hBinRenderer->conv_band, hBinRenderer->timeSlots, &( st_ivas->hRenderConfig->roomAcoustics ), st_ivas->hDecoderConfig->output_Fs, st_ivas->hHrtfFastConv->fastconvReverberationTimes_fx, st_ivas->hHrtfFastConv->fastconvReverberationEneCorrections_fx ) ), IVAS_ERR_OK ) )
         {
diff --git a/lib_rend/ivas_rotation_fx.c b/lib_rend/ivas_rotation_fx.c
index 92ad8d36f4f55496349855e354687c3a25a0a9b3..5d2f393bb7649b330e267aed27db447c4ef5b3d8 100644
--- a/lib_rend/ivas_rotation_fx.c
+++ b/lib_rend/ivas_rotation_fx.c
@@ -1173,6 +1173,9 @@ void rotateFrame_sd_cldfb_fixed(
         IF( hEFAPdata != NULL && ( NE_16( extract_l( L_shr( hOutputSetup->ls_azimuth_fx[n], Q22 ) ), azimuth ) || NE_16( extract_l( L_shr( hOutputSetup->ls_elevation_fx[n], Q22 ) ), elevation ) ) )
         {
             efap_determine_gains_fx( hEFAPdata, gains_fx[n], L_shl( azimuth, Q22 ), L_shl( elevation, Q22 ), EFAP_MODE_EFAP );
+#ifdef FIX_1835_REVERB_ACTIVATION
+            scale_sig32( gains_fx[n], hEFAPdata->numSpk, Q1 ); // gains_fx: Q31
+#endif
         }
         ELSE
         {