Apple TV 4k and Dolby Digital 5.1 Speaker Testing

[PCFan]

I have a Yamaha YAS-107 soundbar and I have my Apple TV 4k connected to my TV through HDMI and my TV connected to my soundbar through optical. Is the full Dolby Digital 5.1 audio signal still going to my soundbar during watching 5.1 content in Netflix and iTunes on my Apple TV 4k or is my TV dropping the .1 channel and only sending a 5.0 signal to my soundbar? Is there a program for the Apple TV that does audio channel testing so that I know that I'm getting the full 5.1 audio signal to my soundbar? My soundbar has 2 integrated subwoofers and a subwoofer output connector but it does not come with a real subwoofer. My TV is the Sony KDL40W600B and the specs for my TV from the manufacturer's website say it does support Dolby Digital audio and 5.1 audio. My soundbar does not show how many audio channels are in the audio signal that's going to the soundbar, just the Dolby Digital LED lights up when receiving a 5.1 Dolby Digital signal.