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.

[PCFan]

I found an application called Speaker Check in the App Store on my iPhone and I downloaded and tried that application through my iPhone airplayed to my Apple TV 4k,. The full Dolby Digital 5.1 signal bitstreaming from the Apple TV 4k is being sent to my soundbar via Apple TV 4k (HDMI ) to TV (optical) to soundbar. However, when I set my Apple TV 4k's surround mode to Stereo or Best Quality, no sound comes out of the LFE during the speaker test just like no sound came out of the LFE during the speaker test in Windows in my PC when using optical to the soundbar from the TV. Is this because optical only supports stereo PCM and Stereo and Best Quality in the Apple TV 4k is PCM? Also this is not a true 5.1 soundbar but it accepts a Dolby Digital 5.1 signal and downmixes the signal to Dolby Digital 2.1 (if the built-in subwoofers are considered the .1 channel).

[Vor4]

I have a friend that bought the same soundbar as you about three weeks ago. He returned it due to the optical cable input pushing out the optical cable on a weekly basis. He ended up buying a really nice JBL soundbar system. This is the model he bought, https://www.bestbuy.com/site/jbl-cin...?skuId=5706009.