diff --git a/hardware/AFSK.c b/hardware/AFSK.c
index a4866ba..c8c5f90 100644
--- a/hardware/AFSK.c
+++ b/hardware/AFSK.c
@@ -340,8 +340,16 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
         afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 2;
         // The above is a simplification of:
         // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 2.899043379;
+    #elif FILTER_CUTOFF == 1200
+        afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 1;
+        // The above is a simplification of:
+        // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 2.228465666;
+    #elif FILTER_CUTOFF == 1600
+        afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 1;
+        // The above is a simplification of:
+        // afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 1.881349100;
     #else
-        #error Unsupported bitrate!
+        #error Unsupported filter cutoff!
     #endif
 
     afsk->iirY[0] = afsk->iirY[1];
@@ -354,8 +362,16 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
         afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 3);
         // The above is a simplification of a first-order 800Hz chebyshev filter:
         // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.3101172565);
+    #elif FILTER_CUTOFF == 1200
+        afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 10);
+        // The above is a simplification of a first-order 800Hz chebyshev filter:
+        // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.1025215106);
+    #elif FILTER_CUTOFF == 1600
+        afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + -1*(afsk->iirY[0] / 17);
+        // The above is a simplification of a first-order 800Hz chebyshev filter:
+        // afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * -0.0630669239);
     #else
-        #error Unsupported bitrate!
+        #error Unsupported filter cutoff!
     #endif
 
 
diff --git a/hardware/AFSK.h b/hardware/AFSK.h
index aab4823..aecce47 100644
--- a/hardware/AFSK.h
+++ b/hardware/AFSK.h
@@ -44,15 +44,20 @@ inline static uint8_t sinSample(uint16_t i) {
 #define CONFIG_AFSK_RXTIMEOUT 0
 #define CONFIG_AFSK_PREAMBLE_LEN 150UL
 #define CONFIG_AFSK_TRAILER_LEN 50UL
+#define BIT_STUFF_LEN 5
+
 #define SAMPLERATE 9600
-#define BITRATE    1600
+#define BITRATE    1200
+
+#define SAMPLESPERBIT (SAMPLERATE / BITRATE)
+#define PHASE_INC    1                              // Nudge by an eigth of a sample each adjustment
 
 #if BITRATE == 960
     #define FILTER_CUTOFF 600
-    #define MARK_FREQ  1300
-    #define SPACE_FREQ 2100
-    #define PHASE_BITS   8                          // How much to increment phase counter each sample
-#if BITRATE == 1200
+    #define MARK_FREQ  960
+    #define SPACE_FREQ 1600
+    #define PHASE_BITS   10                         // How much to increment phase counter each sample
+#elif BITRATE == 1200
     #define FILTER_CUTOFF 600
     #define MARK_FREQ  1200
     #define SPACE_FREQ 2200
@@ -60,15 +65,17 @@ inline static uint8_t sinSample(uint16_t i) {
 #elif BITRATE == 1600
     #define FILTER_CUTOFF 800
     #define MARK_FREQ  1600
-    #define SPACE_FREQ 2800
-    #define PHASE_BITS   6
+    #define SPACE_FREQ 2600
+    #define PHASE_BITS   8
+#elif BITRATE == 2400
+    #define FILTER_CUTOFF 1600
+    #define MARK_FREQ  2400
+    #define SPACE_FREQ 4200
+    #define PHASE_BITS   4
 #else
     #error Unsupported bitrate!
 #endif
 
-#define SAMPLESPERBIT (SAMPLERATE / BITRATE)
-#define BIT_STUFF_LEN 5
-#define PHASE_INC    1                              // Nudge by an eigth of a sample each adjustment
 #define PHASE_MAX    (SAMPLESPERBIT * PHASE_BITS)   // Resolution of our phase counter = 64
 #define PHASE_THRESHOLD  (PHASE_MAX / 2)            // Target transition point of our phase window