Unless you have a different HDMI switch than the ones commonly sold by Monoprice, this will not work in most cases. As I stated above, HDMI audio is heavily dependent on handshake, or EDID to be precise. When you connect such switch to a TV, the TV's EDID will be send back and hence limit to PCM 2.0 as most ppl who bought this kind of HDMI switch to TOS output found out. Monoprice have to put a disclaimer on its site. The only time it will successfully pass through DD 5.1 or DTS 5.1 is from a playback device that can force HDMI audio output regardless of EDID, e.g. PS3.
That's why you need a new HDMI AVR.