I’d connect the Beam through the optical connection on the back of your TV, connected to the adapter that came with the Beam, and then use the HDMI-ARC for the headphones. That will keep the Beam from interfering with any of that HDMI-ARC stuff.

Thanks for the response, Bruce!

I initially had the Beam set up with optical, but it resulted in a slight audio lag. Is that not normal?

I think I would prefer no lag to headphones, if given the choice. I understand these are real first world problems though... 

Not normal at all…. that implies an issue with your TV set sending the optical signal. Double check all the audio settings on the YV, and make sure the audio signal is untouched/unmodified as possible. Also check to be sure it’s set to fixed, rather than variable. I seem to recall one of my older Sony’s had such a setting. Worth checking the TV for software updates, too, some manufacturers have changed their software to deal with pass through more effectively. Oh, while you’re poking around in settings, double check that all devices connected to your TV are set to send a Dolby Digital signal. 

Light is, as you know, pretty speedy And the processing done by Sonos is small enough that it doesn’t add enough delay to be noticeable, probably less than a couple of milliseconds, way too small to effectively measure with your ears and eyes. This points to a delay in you TV somewhere.

If you’re willing to spend $50, I can prove the delay is in the TV set ;) 

Thanks again, Bruce!! I will try and troubleshoot this this weekend if I am feeling patient. 

I’ve yet to meet a Bluetooth transmitter that can be fed using HDMI-ARC. I’d recommend leaving the Beam wired via HDMI and adding an optical-Bluetooth transmitter, preferably aptX Low Latency (which would require the headphones to also support it).

Most TVs wouldn’t need any fiddling in the settings after initial setup, as the optical output should be live all the time. The optical must be configured to send PCM Stereo.

Never looked at bluetooth transmitters at any length, but keeping the two methods of connection separate is, I think, key to not having any issues. If the Bluetooth transmitter only has RCA inputs, then I’d look for RCA outputs on the back of the TV set, and leave the Beam connected via HDMI, as ratty suggests.

Since the OP is talking about purchasing a BT transmitter I’d strongly recommend getting one with an optical input (plus aptX-LL). Why pass the signal through an indifferent quality DAC and ADC when one doesn’t have to?