Recently, Amazon has focused more and more on audio quality. Using Echo devices as a wireless audio solution for your TV is therefore a smart move. Customers with the latest generation of Echo and Echo Plus can wirelessly stream Dolby audio, and customers with Echo Studio can stream Dolby Atmos sound. Of course, it only works with content you play on a compatible Fire TV device, and since this works in stereo configuration, it may not be the same as a home theater definition.
If you want to try this at home, connect your Fire TV and Echo devices to the same network and the same Amazon account. Use the Alexa app to select your audio settings, then follow the instructions on the screen.
You need a Fire TV Stick 4K, Fire TV (third generation), Fire TV Cube (first generation and US only) or Fire TV Cube (second generation). And at least one of the compatible echo devices: Echo Dot (third generation), Echo (second or third generation), Echo Plus (first or second generation), Echo Dot with clock, Echo Studio.