I watch Netflix, Amazon, etc on my PC with a pair of good quality stereo headphones which I've had for years.

'Old' shows are fine (I'm thinking anything prior to around 2005 - 2010), no problems at all with the audio, I can make out everything that the characters say, the mixing is good, etc. However, everything after that is a variable mess and I often need to rewind and briefly turn on the subtitles to hear some dialog that I couldn't make out. This applies to movies as well.