diff --git a/module_usb_audio/endpoint0/descriptors.h b/module_usb_audio/endpoint0/descriptors.h
index da6cb44c..4848825b 100644
--- a/module_usb_audio/endpoint0/descriptors.h
+++ b/module_usb_audio/endpoint0/descriptors.h
@@ -2263,9 +2263,12 @@ const unsigned num_freqs_a1 = MAX(3, (0
 #define NUM_CONTROL_INTERFACES 0
 #endif
 
+/* Total number of bytes returned for the class-specific AudioControl interface descriptor. 
+ * Includes the combined length of this descriptor header and all Unit and Terminal descriptors 
+ * For us this is IT -> FU -> OT * 2 and a header */
 #define AC_TOTAL_LENGTH             (AC_LENGTH + \
-                                    (INPUT_INTERFACES_A1 *  (9 + (7* INPUT_VOLUME_CONTROL) + (NUM_USB_CHAN_IN_FS * INPUT_VOLUME_CONTROL)  + num_freqs_a1 * 3)) +\
-                                    (OUTPUT_INTERFACES_A1 * (9 + (7 * OUTPUT_VOLUME_CONTROL) + (NUM_USB_CHAN_OUT_FS * OUTPUT_VOLUME_CONTROL) + (num_freqs_a1 *3))))
+                                    (INPUT_INTERFACES_A1 *  (12 + ( (8 + NUM_USB_CHAN_IN_FS) * INPUT_VOLUME_CONTROL) + 9)) +\
+                                    (OUTPUT_INTERFACES_A1 * (12 + ( (8 + NUM_USB_CHAN_OUT_FS) * OUTPUT_VOLUME_CONTROL) + 9)))
 
 #define STREAMING_INTERFACES        (INPUT_INTERFACES_A1 + OUTPUT_INTERFACES_A1)
 
@@ -2274,9 +2277,9 @@ const unsigned num_freqs_a1 = MAX(3, (0
 #define NUM_INTERFACES_A1           (1+INPUT_INTERFACES_A1 + OUTPUT_INTERFACES_A1+NUM_CONTROL_INTERFACES)
 
 #if (NUM_USB_CHAN_IN == 0) || defined(UAC_FORCE_FEEDBACK_EP)
-#define CFG_TOTAL_LENGTH_A1         (18 + AC_TOTAL_LENGTH + (INPUT_INTERFACES_A1 * 61) + (OUTPUT_INTERFACES_A1 * 70) + CONTROL_INTERFACE_BYTES)
+#define CFG_TOTAL_LENGTH_A1         (18 + AC_TOTAL_LENGTH + (INPUT_INTERFACES_A1 * (49 + num_freqs_a1 * 3)) + (OUTPUT_INTERFACES_A1 * (58 + num_freqs_a1 * 3)) + CONTROL_INTERFACE_BYTES)
 #else
-#define CFG_TOTAL_LENGTH_A1         (18 + AC_TOTAL_LENGTH + (INPUT_INTERFACES_A1 * 61) + (OUTPUT_INTERFACES_A1 * 61) + CONTROL_INTERFACE_BYTES)
+#define CFG_TOTAL_LENGTH_A1         (18 + AC_TOTAL_LENGTH + (INPUT_INTERFACES_A1 * (49 + num_freqs_a1 * 3)) + (OUTPUT_INTERFACES_A1 * (49 + num_freqs_a1 * 3)) + CONTROL_INTERFACE_BYTES)
 #endif
 
 #define CHARIFY_SR(x) (x & 0xff),((x & 0xff00)>> 8),((x & 0xff0000)>> 16)