Anyone know what frequency the HR-21's IR is set to? Reason I ask is I'm using an audio authority matrix switcher to control multiple devices. I recently just got the LCD proof IR receivers from xantech but seem to be having problems getting the HR-21 to respond to any signal. My other devices work fine but not the HR-21. On the back of the Xantech IR receiver you can adjust the frequency. So far nothings working. Anyone else using the xantech 291-80 IR receivers?