Samsung UN75ES9000F E-Manual page 677

Precautions for Using an IR Blaster
N
To use an IR Blaster, the IR Blaster
must be located nearby with external
devices connected to the TV.
N
Note that it should be no obstacle
between the external device's IR
receiver and an IR Blaster.
N
Install the IR Blaster within 50 cm
and 45 degrees of the up, down, left
and right directions of the IR sensor
of the external device.