diff --git a/DMRTX.cpp b/DMRTX.cpp
index e6238dd..69fa3eb 100644
--- a/DMRTX.cpp
+++ b/DMRTX.cpp
@@ -27,6 +27,7 @@
 #define USE8
 // #define USE6
 // #define USE4
+// #define USE2
 
 #if defined(USE8)
 // Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
@@ -45,8 +46,12 @@ const uint16_t DMR_C4FSK_FILTER_LEN = 32U;
 static q15_t DMR_C4FSK_FILTER[] = {688, -680, -2158, -3060, -2724, -775, 2684, 7041, 11310, 14425, 15565, 14425,
                                    11310, 7041, 2684, -775, -2724, -3060, -2158, -680, 688, 0};
 const uint16_t DMR_C4FSK_FILTER_LEN = 22U;
+#elif defined(USE2)
+// Generated using rcosdesign(0.2, 2, 5, 'sqrt') in MATLAB
+static q15_t DMR_C4FSK_FILTER[] = {-792, 2742, 7192, 11553, 14735, 15900, 14735, 11553, 7192, 2742, -792, 0};
+const uint16_t DMR_C4FSK_FILTER_LEN = 12U;
 #else
-#error "Must define one of USE8, USE6, or USE4."
+#error "Must define one of USE8, USE6, USE4, or USE2."
 #endif
 
 const q15_t DMR_LEVELA[] = { 640,  640 , 640,  640,  640};
diff --git a/IO.cpp b/IO.cpp
index 3540f10..836c04c 100644
--- a/IO.cpp
+++ b/IO.cpp
@@ -24,11 +24,36 @@
 #include "Globals.h"
 #include "IO.h"
 
+// Uncomment one of the following to change the filter
+#define USE8
+// #define USE6
+// #define USE4
+// #define USE2
+
+#if defined(USE8)
 // Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
-static q15_t   C4FSK_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
+static q15_t C4FSK_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
                                    11237, 14331, 15464, 14331, 11237, 6995, 2667, -770, -2706, -3040, -2144, -675, 683, 1450, 1472, 909, 112,
                                    -553, -847, -731, -340, 104, 401, 0};
 const uint16_t C4FSK_FILTER_LEN = 42U;
+#elif defined(USE6)
+// Generated using rcosdesign(0.2, 6, 5, 'sqrt') in MATLAB
+static q15_t C4FSK_FILTER[] = {-554, 112, 911, 1474, 1452, 684, -676, -2147, -3045, -2710, -772,  2671, 7005,
+                                   11253, 14352, 15486, 14352, 11253, 7005, 2671, -772, -2710, -3045, -2147, -676,
+                                   684, 1452, 1474, 911, 112, -554, 0};
+const uint16_t C4FSK_FILTER_LEN = 32U;
+#elif defined(USE4)
+// Generated using rcosdesign(0.2, 4, 5, 'sqrt') in MATLAB
+static q15_t C4FSK_FILTER[] = {688, -680, -2158, -3060, -2724, -775, 2684, 7041, 11310, 14425, 15565, 14425,
+                                   11310, 7041, 2684, -775, -2724, -3060, -2158, -680, 688, 0};
+const uint16_t C4FSK_FILTER_LEN = 22U;
+#elif defined(USE2)
+// Generated using rcosdesign(0.2, 2, 5, 'sqrt') in MATLAB
+static q15_t C4FSK_FILTER[] = {-792, 2742, 7192, 11553, 14735, 15900, 14735, 11553, 7192, 2742, -792, 0};
+const uint16_t C4FSK_FILTER_LEN = 12U;
+#else
+#error "Must define one of USE8, USE6, USE4, or USE2."
+#endif
 
 // Generated using gaussfir(0.5, 4, 5) in MATLAB
 static q15_t   GMSK_FILTER[] = {8, 104, 760, 3158, 7421, 9866, 7421, 3158, 760, 104, 8, 0};
diff --git a/YSFTX.cpp b/YSFTX.cpp
index 0457b65..df230e6 100644
--- a/YSFTX.cpp
+++ b/YSFTX.cpp
@@ -24,11 +24,36 @@
 
 #include "YSFDefines.h"
 
+// Uncomment one of the following to change the filter
+#define USE8
+// #define USE6
+// #define USE4
+// #define USE2
+
+#if defined(USE8)
 // Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
 static q15_t YSF_C4FSK_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
                                    11237, 14331, 15464, 14331, 11237, 6995, 2667, -770, -2706, -3040, -2144, -675, 683, 1450, 1472, 909, 112,
                                    -553, -847, -731, -340, 104, 401, 0};
 const uint16_t YSF_C4FSK_FILTER_LEN = 42U;
+#elif defined(USE6)
+// Generated using rcosdesign(0.2, 6, 5, 'sqrt') in MATLAB
+static q15_t YSF_C4FSK_FILTER[] = {-554, 112, 911, 1474, 1452, 684, -676, -2147, -3045, -2710, -772,  2671, 7005,
+                                   11253, 14352, 15486, 14352, 11253, 7005, 2671, -772, -2710, -3045, -2147, -676,
+                                   684, 1452, 1474, 911, 112, -554, 0};
+const uint16_t YSF_C4FSK_FILTER_LEN = 32U;
+#elif defined(USE4)
+// Generated using rcosdesign(0.2, 4, 5, 'sqrt') in MATLAB
+static q15_t YSF_C4FSK_FILTER[] = {688, -680, -2158, -3060, -2724, -775, 2684, 7041, 11310, 14425, 15565, 14425,
+                                   11310, 7041, 2684, -775, -2724, -3060, -2158, -680, 688, 0};
+const uint16_t YSF_C4FSK_FILTER_LEN = 22U;
+#elif defined(USE2)
+// Generated using rcosdesign(0.2, 2, 5, 'sqrt') in MATLAB
+static q15_t YSF_C4FSK_FILTER[] = {-792, 2742, 7192, 11553, 14735, 15900, 14735, 11553, 7192, 2742, -792, 0};
+const uint16_t YSF_C4FSK_FILTER_LEN = 12U;
+#else
+#error "Must define one of USE8, USE6, USE4, or USE2."
+#endif
 
 const q15_t YSF_LEVELA[] = { 809,  809,  809,  809,  809};
 const q15_t YSF_LEVELB[] = { 269,  269,  269,  269,  269};