Wireless RS-170 Through a TX-NR808

Ok I can not figure out how to do this the way I want. I have the TX-NR808 and I just got a set of Sennheiser RS170. All of my components are hooked up via HDMI except my computer connects it's audio via an optical cable. The only way I can conceive to hook these up is to the pre-outs of the receiver. The only problem is, these are directly correlated to the speaker output, so I have to turn the sound up on my system to increase the pre-out levels high enough for the headphones to be used. I tried mute and that mutes the pre-out signal too. I don't want to use the headphone jack on the front because I believe the only way to get sound through your speakers is to unplug the cable from the front of the receiver. Is there a way to set the pre-out levels to XXdB and tell them to only run 2-CH processing? I also have a harmony 880 so if someone has an idea for me to program each activity for headphones then I could do that too. Anyone have any ideas or am I missing something really simple here? My other idea was to just hook these up to my TV but I'm not sure if the HDMI out on the receiver sends an audio signal to the TV or not. If it does then I could hook my headphones to the audio out on the TV and that should solve my problems. I have a home theater rack so I was trying to solve the problem through my receiver first before I tried the TV route. Thanks for any help or ideas!

Haha good point thanks. This thing actually switches the speakers to off automatically when you plug in the headphones! If I could manually turn the speakers on and off and adjust the headphone output independently that would be a solution!