Use an HDMI cable rather than an Optical (Toslink) cable if you plan to move up to uncompressed formats like Dolby Atmos in the future. Conclusion

While it is tempting to click on the first "Free Download" link you see, there are several reasons to be cautious:

If you just want to test your system, sites like or Demo-World offer free, legal downloads of movie trailers and Dolby/DTS tech demos in full 5.1 and 7.1 surround sound. How to Ensure You Are Actually Hearing 5.1

Once you have your movie file or stream, ensure your setup is configured correctly:

Left and Right rear speakers (for ambient noise and directional effects).

Set your media player (VLC, Plex, or Smart TV) to "Bitstream" or "Passthrough." This allows your Receiver to do the heavy lifting of decoding the Dolby signal.

In VLC, you can go to Tools > Codec Information to verify if the audio stream actually contains 6 channels (5.1).

Dolby Digital 5.1 is the industry standard for surround sound. The "5.1" refers to the channel configuration:

When you download a movie with a dedicated 5.1 track, you aren't just hearing loud noise; you are hearing a soundstage designed by professional engineers to make you feel like you're inside the film. Why You Should Avoid Shady "Free Download" Links