Rooms suitable for a perimeter loop, but where there is a requirement to limit spill in one direction (e.g. back to back lecture halls).
A carefully designed smaller loop segment correctly wired and of the correct size will cancel spill from the loop in one direction, driven by the same amplifier as the main loop.
True cancellation requires design with simulation tools or a lot of trial and error. Ampetronic can check designs for you or do a design for your application. Cancellation loops require higher voltage headroom in the amplifier than a perimeter loop. A zero signal line will exist between the cancellation loop and the main loop – it is important to ensure that no users will be in the vicinity of this zero line.