Question Question about sound bar and home theater audio output


May 26, 2019
My Home Theater Setup:
TV: LG 55SM8600PUA
4K Disc Player: Sony UBP-X700
Sound System: LG SJ4R Sound bar
Streaming System: Roku Ultra (2019 Model)

Recently, I troubleshooted my home theater setup. Initially, my setup consisted of the components listed above, but at one point I switched my LG SJ4R 4.1 sound bar system with a Samsung HW-N650 sound bar and its optional wireless rear speaker kit, since it was being unused. However, I noticed that while watching 4K Blu Ray discs that occasionally the audio briefly cuts out. The troubleshooting steps that I followed included switching out all of the 4K HDMI Cables with backwards compatible 8K HDMI cables, and switching out the Sony UBP-X700 player with a Samsung UBD-M8500 4K disc player, and doing factory resets of all of my home theater equipment. Even after those steps were carried out, the audio was still cutting out. I then narrowed my suspicion that the problem was the Samsung sound bar. My suspicion was further fueled when I could not update the sound bar's firmware. After that, I re-attached the Sony 4K disc player and LG sound bar to my home theater setup and went a head and did another factory reset of all of the equipment and re-applied the recommended custom video settings for smoother playback. I had tested the setup on four 4K movie discs. On three of the discs, I did not notice any audio drop outs. But on one disc, I noticed the audio cut out at approximately the same point as it did when I was using the Samsung sound bar, which lead me to conclude that the disc was defective.

While watching 4K discs with the LG sound bar providing audio, again I did not notice any audio dropouts. But there were times where scenes in the movie were noticeably quieter. I did several rewinds and replays of those noticeably quieter scenes and as far as I could tell, virtually all of those scenes were still quieter. This lead me to the conclusion that that was how the audio was setup during either the making of the movies or their disc manufacturing processes. Before I forget to mention, my sound sound bar, 4K disc player, and streaming system are all connected to my TV with HDMI cables.

I have heard of the saying that perfection is the enemy of good enough. I know that just like people, machines such as computers and electronics such as those for video and audio are not perfect. Competing brands of a specific product such as a TV or speaker system may have their pros and cons when compared to each other. For example, one TV may do a better job with brights and darks while the competing TV may do a better job with color variations or details and both may have differing image processing capabilities and speeds. Or, one speaker may do a better job with treble while the competing speaker may do a better job with bass. Ultimately, the customer decides which product best meets his/her needs based on tastes, wishes, and budget. The mentioned home theater setup was intended to be put in my bedroom with the TV in front of my bed and the surround sound system around my bed. I was not looking at anything super fancy, but I wanted a good and reliable basic or standard home theater setup for my room.

My question about home theater audio output from audio systems such as sound bars and other types of 5.1/7.1 systems is out of curiosity. Like I said, machines are not perfect. So my question is: Even if everything with my home theater setup including the sound bar, TV, 4K disc player, streaming device and the HDMI cables connecting them are working properly or within their manufacturers' designed specifications and I set all of the audio settings properly such as bass, surround mode, and EQ, and kept the volume level at a reasonable number, such as 10, could the audio output still fluctuate up or down a little during playback [which may or may not be noticeable depending on the viewer's hearing capability (e.g. average listener vs audiophile)] due to reasons such as the quality of the components that make up the devices, the quality of the devices' circuitry that handle audio transmissions, the quality of the HDMI or audio cables, or fluctuations of the electrical current from the wall power outlet or, if applicable, the surge protector?

Also, as a side note I did notice audio dropouts or what appeared to be reductions in volume while streaming content on streaming services such as HBO Max and Disney+ even after completing the mentioned troubleshooting process. Could these audio issues be due to issues with either the streaming app or the streaming service itself (e.g. high traffic at the source location of the streaming content or an internet connection issue anywhere between my house and where the content is being streamed from?