diff --git a/module_usb_audio/audio.xc b/module_usb_audio/audio.xc
index 744b8f70..dd82c037 100755
--- a/module_usb_audio/audio.xc
+++ b/module_usb_audio/audio.xc
@@ -29,12 +29,6 @@ static unsigned samplesOut[NUM_USB_CHAN_OUT];
 static unsigned samplesIn_0[NUM_USB_CHAN_IN];
 static unsigned samplesIn_1[I2S_CHANS_ADC];
 
-#ifdef I2S_MODE_TDM
-#define I2S_CHANS_PER_FRAME 8
-#else
-#define I2S_CHANS_PER_FRAME 2
-#endif
-
 #if (DSD_CHANS_DAC != 0)
 extern buffered out port:32 p_dsd_dac[DSD_CHANS_DAC];
 extern buffered out port:32 p_dsd_clk;
@@ -42,7 +36,6 @@ extern buffered out port:32 p_dsd_clk;
 
 unsigned g_adcVal = 0;
 
-
 #ifdef XTA_TIMING_AUDIO
 #pragma xta command "add exclusion received_command"
 #pragma xta command "analyse path i2s_output_l i2s_output_r"
diff --git a/module_usb_audio/devicedefines.h b/module_usb_audio/devicedefines.h
index 7ca77aff..08012067 100644
--- a/module_usb_audio/devicedefines.h
+++ b/module_usb_audio/devicedefines.h
@@ -101,6 +101,20 @@
 #endif
 #endif
 
+/**
+ * @brief Channels per I2S frame. *
+ *
+ * Default: 2 i.e standard stereo I2S (8 if using TDM i.e. I2S_MODE_TDM). 
+ *
+ **/
+#ifndef I2S_CHANS_PER_FRAME
+#ifdef I2S_MODE_TDM
+#define I2S_CHANS_PER_FRAME 8
+#else
+#define I2S_CHANS_PER_FRAME 2
+#endif
+#endif
+
 /**
  * @brief Max supported sample frequency for device (Hz). Default: 192000
  */