diff --git a/lib_com/options.h b/lib_com/options.h
index 34293516096cdbcceb2ca12f1009f982e6834203..f372904f4f7d161f51bc018d5d6bd16b51edb8f2 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -155,6 +155,8 @@
 
 #define REFACTOR_REVERB_INIT_ADD_CFG_CHECKS             /* Simplify and improve reverb initialization + add range checks on config parameter values */ 
 
+#define FIX_I54_LS_CONVERSION                           /* FhG: fix incorrect downmix matrix for 5_1_4 to 5_1_2 and upmix matrix for 7_1 to 7_1_4 */
+
 /* ################## End DEVELOPMENT switches ######################### */
 /* clang-format on */
 #endif
diff --git a/lib_dec/ivas_rom_dec.c b/lib_dec/ivas_rom_dec.c
index 84a0db9765371b500f4347ceaa283a3e457deb98..c442da1c75725ff54e36aadae62fa08b8f26d509 100644
--- a/lib_dec/ivas_rom_dec.c
+++ b/lib_dec/ivas_rom_dec.c
@@ -580,6 +580,23 @@ const LS_CONVERSION_MATRIX ls_conversion_cicp14_cicp6[] =
     {43, 0.849999964f}
 };
 
+#ifdef FIX_I54_LS_CONVERSION
+const LS_CONVERSION_MATRIX ls_conversion_cicp14_cicp12[] =
+{
+    /* First row indicates the number of non-zero elements */
+    {8, 0.0f},
+    /* Index of non-zero element, value of non-zero element*/
+    {0,  1.000000000f},
+    {9,  1.000000000f},
+    {18, 1.000000000f},
+    {27, 1.000000000f},
+    {36, 1.000000000f},
+    {45, 1.000000000f},
+    {48, 0.849999964f},
+    {57, 0.849999964f}
+};
+#endif
+
 const LS_CONVERSION_MATRIX ls_conversion_cicp16_cicp6[] =
 {
     /* First row indicates the number of non-zero elements */
@@ -620,6 +637,18 @@ const LS_CONVERSION_MATRIX ls_conversion_cicp16_cicp14[] =
     /* First row indicates the number of non-zero elements */
     {10, 0.0f},
     /* Index of non-zero element, value of non-zero element*/
+#ifdef FIX_I54_LS_CONVERSION
+    {0,  1.000000000f},
+    {9,  1.000000000f},
+    {18, 1.000000000f},
+    {27, 1.000000000f},
+    {36, 1.000000000f},
+    {45, 1.000000000f},
+    {54, 1.000000000f},
+    {63, 1.000000000f},
+    {68, 0.849999964f},
+    {77, 0.849999964f},
+#else
     {0,  1.000000000f},
     {11, 1.000000000f},
     {22, 1.000000000f},
@@ -630,6 +659,7 @@ const LS_CONVERSION_MATRIX ls_conversion_cicp16_cicp14[] =
     {59, 0.849999964f},
     {66, 1.000000000f},
     {77, 1.000000000f},
+#endif
 };
 
 const LS_CONVERSION_MATRIX ls_conversion_cicp19_cicp6[] =
@@ -747,6 +777,23 @@ const LS_CONVERSION_MATRIX ls_conversion_cicp12_cicp16[] =
     {75, 1.0f}
 };
 
+#ifdef FIX_I54_LS_CONVERSION
+const LS_CONVERSION_MATRIX ls_conversion_cicp12_cicp19[] =
+{
+    /* First row indicates the number of non-zero elements */
+    {8,  0.0f},
+    /* Index of non-zero element, value of non-zero element*/
+    {0,  1.0f},
+    {13, 1.0f},
+    {26, 1.0f},
+    {39, 1.0f},
+    {54, 1.0f},
+    {67, 1.0f},
+    {76, 1.0f},
+    {89, 1.0f}
+};
+#endif
+
 const LS_CONVERSION_MATRIX ls_conversion_cicp14_cicp19[] =
 {
     /* First row indicates the number of non-zero elements */
@@ -802,7 +849,11 @@ const LS_CONVERSION_MAPPING ls_conversion_mapping[LS_SETUP_CONVERSION_NUM_MAPPIN
     {AUDIO_CONFIG_7_1,   AUDIO_CONFIG_5_1,   ls_conversion_cicp12_cicp6},
 
     {AUDIO_CONFIG_5_1_2, AUDIO_CONFIG_5_1,   ls_conversion_cicp14_cicp6},
+#ifdef FIX_I54_LS_CONVERSION
+    {AUDIO_CONFIG_5_1_2, AUDIO_CONFIG_7_1,   ls_conversion_cicp14_cicp12},
+#else
     {AUDIO_CONFIG_5_1_2, AUDIO_CONFIG_7_1,   ls_conversion_cicp14_cicp6},
+#endif
 
     {AUDIO_CONFIG_5_1_4, AUDIO_CONFIG_5_1,   ls_conversion_cicp16_cicp6},
     {AUDIO_CONFIG_5_1_4, AUDIO_CONFIG_7_1,   ls_conversion_cicp16_cicp12},
@@ -827,7 +878,11 @@ const LS_CONVERSION_MAPPING ls_conversion_mapping[LS_SETUP_CONVERSION_NUM_MAPPIN
 
     {AUDIO_CONFIG_7_1, AUDIO_CONFIG_5_1_2, ls_conversion_cicp12_cicp14},
     {AUDIO_CONFIG_7_1, AUDIO_CONFIG_5_1_4, ls_conversion_cicp12_cicp16},
+#ifdef FIX_I54_LS_CONVERSION
+    {AUDIO_CONFIG_7_1, AUDIO_CONFIG_7_1_4, ls_conversion_cicp12_cicp19},
+#else
     {AUDIO_CONFIG_7_1, AUDIO_CONFIG_7_1_4, NULL},
+#endif
 
     {AUDIO_CONFIG_5_1_2, AUDIO_CONFIG_5_1_4, NULL},
     {AUDIO_CONFIG_5_1_2, AUDIO_CONFIG_7_1_4, ls_conversion_cicp14_cicp19},
diff --git a/lib_dec/ivas_rom_dec.h b/lib_dec/ivas_rom_dec.h
index 5979d8d64bcd367305c41f84a45a0bb65e0c1da8..a445f1e2cfae4a63f76f4709d162155fe2e4d7d6 100644
--- a/lib_dec/ivas_rom_dec.h
+++ b/lib_dec/ivas_rom_dec.h
@@ -120,6 +120,9 @@ extern const float ls_conversion_cicpX_stereo[12][2];
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp12_cicp6[];
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp12_cicp6[];
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp14_cicp6[];
+#ifdef FIX_I54_LS_CONVERSION
+extern const LS_CONVERSION_MATRIX ls_conversion_cicp14_cicp12[];
+#endif
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp16_cicp6[];
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp16_cicp14[];
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp19_cicp6[];
@@ -130,6 +133,9 @@ extern const LS_CONVERSION_MATRIX ls_conversion_cicp19_cicp16[];
 /* Upmix matrices */
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp12_cicp14[];
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp12_cicp16[];
+#ifdef FIX_I54_LS_CONVERSION
+extern const LS_CONVERSION_MATRIX ls_conversion_cicp12_cicp19[];
+#endif
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp14_cicp19[];
 extern const LS_CONVERSION_MATRIX ls_conversion_cicp16_cicp19[];
 
diff --git a/scripts/pyaudio3dtools/constants.py b/scripts/pyaudio3dtools/constants.py
index 7a6872545143e311369e81cd306563dd0371d29e..24c8b7aaba76b9da7ff113db7d481eb491469126 100644
--- a/scripts/pyaudio3dtools/constants.py
+++ b/scripts/pyaudio3dtools/constants.py
@@ -78,17 +78,17 @@ IVAS_CICP14_TO_6 = IVAS_CICP14_TO_6.reshape(8, 6)
 
 IVAS_CICP16_TO_6 = np.zeros(10 * 6)
 IVAS_CICP16_TO_6[[0, 7, 14, 21, 28, 35]] = 1
-IVAS_CICP16_TO_6[[36, 43, 52, 59]] = 0.89999964
+IVAS_CICP16_TO_6[[36, 43, 52, 59]] = 0.849999964
 IVAS_CICP16_TO_6 = IVAS_CICP16_TO_6.reshape(10, 6)
 
 IVAS_CICP16_TO_12 = np.zeros(10 * 8)
 IVAS_CICP16_TO_12[[0, 9, 18, 27, 36, 45]] = 1
-IVAS_CICP16_TO_12[[48, 57, 68, 77]] = 0.89999964
+IVAS_CICP16_TO_12[[48, 57, 68, 77]] = 0.849999964
 IVAS_CICP16_TO_12 = IVAS_CICP16_TO_12.reshape(10, 8)
 
 IVAS_CICP16_TO_14 = np.zeros(10 * 8)
 IVAS_CICP16_TO_14[[0, 9, 18, 27, 36, 45, 54, 63]] = 1
-IVAS_CICP16_TO_14[[68, 77]] = 0.899999964
+IVAS_CICP16_TO_14[[68, 77]] = 0.849999964
 IVAS_CICP16_TO_14 = IVAS_CICP16_TO_14.reshape(10, 8)
 
 IVAS_CICP19_TO_6 = np.zeros(12 * 6)
@@ -134,6 +134,10 @@ IVAS_CICP12_TO_16 = np.zeros(8 * 10)
 IVAS_CICP12_TO_16[[0, 11, 22, 33, 44, 55, 64, 75]] = 1
 IVAS_CICP12_TO_16 = IVAS_CICP12_TO_16.reshape(8, 10)
 
+IVAS_CICP12_TO_19 = np.zeros(8 * 12)
+IVAS_CICP12_TO_19[[0, 13, 26, 39, 54, 67, 76, 89]] = 1
+IVAS_CICP12_TO_19 = IVAS_CICP12_TO_19.reshape(8, 12)
+
 IVAS_CICP14_TO_19 = np.zeros(8 * 12)
 IVAS_CICP14_TO_19[[0, 13, 26, 39, 52, 65, 80, 93]] = 1
 IVAS_CICP14_TO_19 = IVAS_CICP14_TO_19.reshape(8, 12)
@@ -178,7 +182,7 @@ IVAS_MC_CONVERSION = {
         # upmix
         "5_1_2": IVAS_CICP12_TO_14,
         "5_1_4": IVAS_CICP12_TO_16,
-        "7_1_4": np.pad(np.eye(8), [[0, 0], [0, 4]]),
+        "7_1_4": IVAS_CICP12_TO_19,
     },
     "5_1_2": {
         # downmix