diff --git a/software/sys_controller/ossc/av_controller.c b/software/sys_controller/ossc/av_controller.c
index 1d75403..b207ac3 100644
--- a/software/sys_controller/ossc/av_controller.c
+++ b/software/sys_controller/ossc/av_controller.c
@@ -154,17 +154,17 @@ void set_lpf(alt_u8 lpf)
             break;
         case VIDEO_HDTV:
             tvp_set_lpf(0);
-            ths_set_lpf(THS_LPF_BYPASS);
+            ths_set_lpf((pclk < 80000000) ? THS_LPF_35MHZ : THS_LPF_BYPASS);
             break;
         case VIDEO_EDTV:
             tvp_set_lpf(0);
-            ths_set_lpf(1);
+            ths_set_lpf(THS_LPF_16MHZ);
             break;
         case VIDEO_SDTV:
         case VIDEO_LDTV:
         default:
             tvp_set_lpf(0);
-            ths_set_lpf(0);
+            ths_set_lpf(THS_LPF_9MHZ);
             break;
         }
     } else {
diff --git a/software/sys_controller/ths7353/ths7353.h b/software/sys_controller/ths7353/ths7353.h
index 2204ee3..7df6ce6 100644
--- a/software/sys_controller/ths7353/ths7353.h
+++ b/software/sys_controller/ths7353/ths7353.h
@@ -34,6 +34,10 @@ typedef enum {
     THS_STANDBY = 2
 } ths_input_t;
 
+#define THS_LPF_9MHZ 0x00
+#define THS_LPF_16MHZ 0x01
+#define THS_LPF_35MHZ 0x02
+#define THS_LPF_BYPASS 0x03
 #define THS_LPF_DEFAULT 0x3
 #define THS_LPF_MASK 0x18
 #define THS_LPF_OFFS 3
@@ -49,8 +53,6 @@ typedef enum {
 #define THS_MODE_AC_BIAS    4
 #define THS_MODE_STC        6   //mid bias
 
-#define THS_LPF_BYPASS 0x03
-
 int ths_init();
 
 void ths_set_lpf(alt_u8 val);