If you want to achieve the best surround sound effect, it is recommended to use it in an indoor space of 5m x 5m x 5m. For larger spaces, you can use more than two OPSIS II.

You can press twice the connection button, and the main machine will change to slave machine. The connection distance between 2 OPSIS II is 10m, and you don't need to download extra application to connect. User instruction:

As long as the sound source has more than two channels, it can have a certain surround sound effect. The higher the quality and more channels of the sound source,the better the surround sound effect will deliver. This is one of the demo video you can test with OPSIS II and normal speakers:

Your can check our return policy here: https://www.preteraudio.com/returns-warranty

Your can check warranty policy here: https://www.preteraudio.com/returns-warranty