seperate room?

I bought three pairs and use all three transmitters but only one receiver - works great.

is this correct. You can set on in front of the screen and the other across from the equipment rack and that unit has a IR emmiter on it and controls the equipment? Is this correct?

they receive IR transmit RF unit to unit and output IR.

The receiver outputs IR from the front of the unit or you can use a mini-blaster which plugs in to the receiver and can be placed, for example, on the inside of the glass facing your equipment as I've done.