diff --git a/src/fm_mpx.c b/src/fm_mpx.c
index 011b484..44bf32f 100644
--- a/src/fm_mpx.c
+++ b/src/fm_mpx.c
@@ -66,11 +66,7 @@ float fir_buffer_stereo[FIR_SIZE] = {0};
 int fir_index = 0;
 int channels;
 
-//3.185kHz for Europe, 2.120kHz for US
-const float PREEMPHASIS_US = 2120;
-const float PREEMPHASIS_EU = 3185;
 float *last_buffer_val;
-float preemphasis_corner_freq;
 float preemphasis_prewarp;
 float preemphasis_coefficient;
 
@@ -88,7 +84,7 @@ float *alloc_empty_buffer(size_t length) {
 }
 
 
-int fm_mpx_open(char *filename, size_t len) {
+int fm_mpx_open(char *filename, size_t len, float preemphasis_corner_freq) {
     length = len;
 
     if(filename != NULL) {
@@ -128,10 +124,9 @@ int fm_mpx_open(char *filename, size_t len) {
         last_buffer_val = (float*) malloc(sizeof(float)*channels);
         for(int i=0;i<channels;i++) last_buffer_val[i] = 0;
         
-        preemphasis_corner_freq = PREEMPHASIS_EU;
         preemphasis_prewarp = tan(PI*preemphasis_corner_freq/in_samplerate);
         preemphasis_coefficient = (1.0 + (1.0 - preemphasis_prewarp)/(1.0 + preemphasis_prewarp))/2.0;
-        printf("Created preemphasis with with cutoff at %.1f Hz\n", preemphasis_corner_freq);
+        printf("Created preemphasis with cutoff at %.1f Hz\n", preemphasis_corner_freq);
         
     
         // Create the low-pass FIR filter
diff --git a/src/fm_mpx.h b/src/fm_mpx.h
index 81b61be..bd07e4e 100644
--- a/src/fm_mpx.h
+++ b/src/fm_mpx.h
@@ -21,6 +21,6 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-extern int fm_mpx_open(char *filename, size_t len);
+extern int fm_mpx_open(char *filename, size_t len, float preemphasis_corner_freq);
 extern int fm_mpx_get_samples(float *mpx_buffer);
 extern int fm_mpx_close();
\ No newline at end of file
diff --git a/src/pi_fm_rds.c b/src/pi_fm_rds.c
index b8e91b8..da8765e 100644
--- a/src/pi_fm_rds.c
+++ b/src/pi_fm_rds.c
@@ -191,7 +191,6 @@
 // (broadcast radio) and about 3.5 for NBFM (walkie-talkie style radio)
 #define DEVIATION        25.0
 
-
 typedef struct {
     uint32_t info, src, dst, length,
          stride, next, pad[2];
@@ -311,7 +310,7 @@ map_peripheral(uint32_t base, uint32_t len)
 #define DATA_SIZE 5000
 
 
-int tx(uint32_t carrier_freq, char *audio_file, uint16_t pi, char *ps, char *rt, float ppm, char *control_pipe) {
+int tx(uint32_t carrier_freq, char *audio_file, uint16_t pi, char *ps, char *rt, float ppm, char *control_pipe, float preemphasis_cutoff) {
     // Catch all signals possible - it is vital we kill the DMA engine
     // on process exit!
     for (int i = 0; i < 64; i++) {
@@ -446,7 +445,7 @@ int tx(uint32_t carrier_freq, char *audio_file, uint16_t pi, char *ps, char *rt,
     int data_index = 0;
 
     // Initialize the baseband generator
-    if(fm_mpx_open(audio_file, DATA_SIZE) < 0) return 1;
+    if(fm_mpx_open(audio_file, DATA_SIZE, preemphasis_cutoff) < 0) return 1;
     
     // Initialize the RDS modulator
     char myps[9] = {0};
@@ -537,6 +536,8 @@ int tx(uint32_t carrier_freq, char *audio_file, uint16_t pi, char *ps, char *rt,
     return 0;
 }
 
+#define PREEMPHASIS_EU 3185
+#define PREEMPHASIS_US 2120
 
 int main(int argc, char **argv) {
     char *audio_file = NULL;
@@ -546,6 +547,7 @@ int main(int argc, char **argv) {
     char *rt = "PiFmRds: live FM-RDS transmission from the RaspberryPi";
     uint16_t pi = 0x1234;
     float ppm = 0;
+	float preemphasis_cutoff = PREEMPHASIS_US;
     
     
     // Parse command-line arguments
@@ -578,6 +580,16 @@ int main(int argc, char **argv) {
         } else if(strcmp("-ctl", arg)==0 && param != NULL) {
             i++;
             control_pipe = param;
+		} else if(strcmp("-preemph", arg)==0 && param != NULL) {
+			i++;
+			if(strcmp("eu", param)==0) {
+				preemphasis_cutoff = PREEMPHASIS_EU;
+			} else if(strcmp("us", param)==0) {
+				preemphasis_cutoff = PREEMPHASIS_US;
+			}
+			else {
+				preemphasis_cutoff = atof(param);
+			}
         } else {
             fatal("Unrecognised argument: %s.\n"
             "Syntax: pi_fm_rds [-freq freq] [-audio file] [-ppm ppm_error] [-pi pi_code]\n"
@@ -585,7 +597,7 @@ int main(int argc, char **argv) {
         }
     }
     
-    int errcode = tx(carrier_freq, audio_file, pi, ps, rt, ppm, control_pipe);
+    int errcode = tx(carrier_freq, audio_file, pi, ps, rt, ppm, control_pipe, preemphasis_cutoff);
     
     terminate(errcode);
 }