diff --git a/lib_com/options.h b/lib_com/options.h
index 6579999f28044ff0135600ea87d9cabd47d8fc8a..89b802e7203be877620f77f053047a1abe85eedc 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -151,6 +151,8 @@
 #define FIX_BASOP_2517_CLICK_IN_OMASA_LTV               /* FhG: BASOP #2517: preserve precision by removing one-bit headroom from Q_min and allowing saturation during buffer scaling */
 #define FIX_BASOP_2559_Q_SYNTH_HISTORY_RESET            /* FhG: BASOP issue 2559: reset hTcxDec->q_synth_history_fx in allocate_CoreCoder_TCX_fx() */
 #define FIX_FLOAT_1578_OMASA_REND_SPIKES                /* Nokia: Float issue 1578: Fix spikes and collapsed perception in OMASA/MASA rendering to FOA/HOA */
+#define FIX_1521_SBA_LOUDNESS_STEREO                    /* FhG: issue 1521: Fix loudness for SBA to stereo rendering */
+#define FIX_1521_SBA_LOUDNESS_BINAURAL                  /* FhG: issue 1521: Fix loudness for SBA to binaural rendering */
 
 /* ##################### End NON-BE switches ########################### */
 
diff --git a/lib_dec/ivas_dec_render_fx.c b/lib_dec/ivas_dec_render_fx.c
index ee5105fdebb2c9d9ac44912ada0df77aec7fa0fb..71dec56297e026028391202071b77d1d8baae828 100644
--- a/lib_dec/ivas_dec_render_fx.c
+++ b/lib_dec/ivas_dec_render_fx.c
@@ -440,6 +440,24 @@ ivas_error ivas_dec_render_fx(
                 return error;
             }
         }
+#ifdef FIX_1521_SBA_LOUDNESS_BINAURAL
+        test();
+        test();
+        test();
+        IF( EQ_32( st_ivas->ivas_format, SBA_FORMAT ) &&
+            ( EQ_32( st_ivas->renderer_type, RENDERER_BINAURAL_PARAMETRIC ) ||
+              EQ_32( st_ivas->renderer_type, RENDERER_BINAURAL_PARAMETRIC_ROOM ) ||
+              EQ_32( st_ivas->renderer_type, RENDERER_BINAURAL_FASTCONV ) ) )
+        {
+            /* loudness correction for SBA binaural rendering */
+            nchan_out_syn_output = ( st_ivas->hSplitBinRend != NULL ) ? st_ivas->hSplitBinRend->splitrend.multiBinPoseData.num_poses * BINAURAL_CHANNELS : BINAURAL_CHANNELS;
+            move16();
+            FOR( n = 0; n < nchan_out_syn_output; n++ )
+            {
+                v_multc_fx( p_output_fx[n], INV_SQRT2_FX, p_output_fx[n], *nSamplesRendered );
+            }
+        }
+#endif
     }
     ELSE IF( EQ_32( st_ivas->ivas_format, MASA_ISM_FORMAT ) )
     {
diff --git a/lib_dec/ivas_sba_dirac_stereo_dec_fx.c b/lib_dec/ivas_sba_dirac_stereo_dec_fx.c
index 905d62d3cfa776ef1651cd4825ba680fe29e2d1e..1d15b3d291a517dabde3e8f20323db25bf0ca526 100644
--- a/lib_dec/ivas_sba_dirac_stereo_dec_fx.c
+++ b/lib_dec/ivas_sba_dirac_stereo_dec_fx.c
@@ -1566,11 +1566,33 @@ void ivas_sba_dirac_stereo_dec_fx(
     synchro_synthesis_fx( st_ivas->hDecoderConfig->ivas_total_brate, hCPE, output, output_frame, 1 /*st_ivas->sba_dirac_stereo_flag*/, q_dft[0] );
 
     /* output scaling */
+#ifdef FIX_1521_SBA_LOUDNESS_STEREO
+    IF( !sba_mono_flag )
+#else
     test();
     IF( !sba_mono_flag && !( EQ_16( st_ivas->ivas_format, SBA_ISM_FORMAT ) && EQ_16( st_ivas->ism_mode, ISM_MODE_NONE ) ) )
+#endif
     {
+#ifdef FIX_1521_SBA_LOUDNESS_STEREO
+        test();
+        IF( EQ_16( st_ivas->ivas_format, SBA_ISM_FORMAT ) && EQ_16( st_ivas->ism_mode, ISM_MODE_NONE ) )
+        {
+            /* low bitrate OSBA needs a makeup gain of 2.f to compensate for the encoder side
+                INV_SQRT2 * 2 = SQRT2  */
+            v_multc_fx( output[0], SQRT2_FX, output[0], output_frame );
+            v_multc_fx( output[1], SQRT2_FX, output[1], output_frame );
+            v_shr( output[0], -1, output[0], output_frame ); /* q_dft */
+            v_shr( output[1], -1, output[1], output_frame ); /* q_dft */
+        }
+        ELSE
+        {
+            v_multc_fx( output[0], INV_SQRT2_FX, output[0], output_frame );
+            v_multc_fx( output[1], INV_SQRT2_FX, output[1], output_frame );
+        }
+#else
         v_shr( output[0], 1, output[0], output_frame ); /*0.5f*/
         v_shr( output[1], 1, output[1], output_frame ); /*0.5f*/
+#endif
     }
 
     /* delay HB synth */
diff --git a/lib_rend/ivas_allrad_dec_fx.c b/lib_rend/ivas_allrad_dec_fx.c
index 2c5c40b9c30c0eabcc2a43a01b21999c0ffeba84..18793c211a65cdc8858b99a381ff10af200bbc57 100644
--- a/lib_rend/ivas_allrad_dec_fx.c
+++ b/lib_rend/ivas_allrad_dec_fx.c
@@ -98,10 +98,17 @@ ivas_error ivas_sba_get_hoa_dec_matrix_fx(
     }
     ELSE IF( EQ_32( hOutSetup.output_config, IVAS_AUDIO_CONFIG_STEREO ) )
     {
+#ifdef FIX_1521_SBA_LOUDNESS_STEREO
+        ( *hoa_dec_mtx )[0] = INV_SQRT2_FX >> 2;
+        ( *hoa_dec_mtx )[1] = INV_SQRT2_FX >> 2;
+        ( *hoa_dec_mtx )[SBA_NHARM_HOA3] = INV_SQRT2_FX >> 2;
+        ( *hoa_dec_mtx )[SBA_NHARM_HOA3 + 1] = -( INV_SQRT2_FX >> 2 );
+#else
         ( *hoa_dec_mtx )[0] = ONE_IN_Q28;                   // 0.5f in Q29
         ( *hoa_dec_mtx )[1] = ONE_IN_Q28;                   // 0.5f in Q29
         ( *hoa_dec_mtx )[SBA_NHARM_HOA3] = ONE_IN_Q28;      // 0.5f in Q29
         ( *hoa_dec_mtx )[SBA_NHARM_HOA3 + 1] = -ONE_IN_Q28; // 0.5f in Q29
+#endif
         move32();
         move32();
         move32();
diff --git a/lib_rend/ivas_crend_fx.c b/lib_rend/ivas_crend_fx.c
index 5e41928918a7834cfefc0d26adc519e431ca8740..e1981b91fb6686c57a954df3d829ea766ee3a566 100644
--- a/lib_rend/ivas_crend_fx.c
+++ b/lib_rend/ivas_crend_fx.c
@@ -2230,7 +2230,20 @@ ivas_error ivas_rend_crendProcessSubframe_fx(
         FOR( ch = 0; ch < BINAURAL_CHANNELS; ch++ )
         {
             /* move to output */
-            Copy32( pcm_tmp_fx[ch], p_output_fx[ch], subframe_len );
+#ifdef FIX_1521_SBA_LOUDNESS_BINAURAL
+            test();
+            IF( EQ_32( inConfigType, IVAS_REND_AUDIO_CONFIG_TYPE_AMBISONICS ) && NE_32( outConfig, IVAS_AUDIO_CONFIG_BINAURAL_ROOM_IR ) )
+            {
+                /* loudness correction for SBA binaural rendering */
+                v_multc_fx( pcm_tmp_fx[ch], INV_SQRT2_FX, p_output_fx[ch], subframe_len );
+            }
+            ELSE
+            {
+#endif
+                Copy32( pcm_tmp_fx[ch], p_output_fx[ch], subframe_len );
+#ifdef FIX_1521_SBA_LOUDNESS_BINAURAL
+            }
+#endif
 
             p_output_fx[ch] += subframe_len;
         }