Best answer by AjTrek1
The port labeled for HDMI_CEC is Samsung's version of HDMI_ARC. I have a Samsung Plasma circa 2013 with a Beam connected to the HDMI_CEC port that supports the Alexa assistant in the Beam to turn TV on but not off.
As I previously had the Beam connected to a Sony circa 2012 all features of the Beam with Alexa worked perfectly. I've come to the conclusion that HDMI_ARC functionally may vary by TV manufacturer.
Alternatively, the Beam can also be connected via optical with the included adapter. However, when configured in that manner Alexa voice control for your TV is not available. Other Alexa features are not affected.
Two of the Play 1's can be bonded to the Beam as surrounds. Also know that your set may or may not pass DD5.1 over optical. If you no longer have the manual (or can't locate it) search online to answer that question by typing "Samsung UN46C6300SF Manual" and you should get a hit.