A:Answer I don't know for sure about your RF headphones specifically, but I plugged my Home Theater Receiver into the "audio out" plug ( on the rear, on the side panel , under the HDMI port - Look for it on P36 of the manual). It disables the internal speakers and allows the volume control on the SonyTV to adjust the sound volume coming out of the Home Theater speakers.
I have to use a second remote to turn the Home Theater on, but from then on, the Channel and Volume are controlled by the Sony factory remote- which is 95% of my watching/listening needs.
You nay have to purchase an adapter to get the TV audio out to match to your RF headphone unit input. Ask a Best Buy technician if you have questions.