When placing vertical stacks, they will be in close proximity to the main speakers, not generally placed in corners, but immediately outside of and slightly behind the main speakers. They should be turned inward toward the center of the room to a position that points directly or almost directly at the prime listening location. A REL specialist trained in vertical stack set-up should be retained for tuning, which is why reference-level product is never sold over the Internet.
* These are recommended best practices for positioning a REL Subwoofer, always refine placement and angle by ear.
** To obtain optimal performance from a REL subwoofer and extend the performance of your speakers, your main speakers must be setup properly. Always follow the setup instructions from your speaker manufacturer first, before setting up your REL.