Sennheiser Set 860 Instruction Manual page 9

Putting the Set 860 into operation
Setting up the transmitter
b
Place the transmitter near your audio source.
b
Separate the transmitter from other wireless devices in the
room by at least 50 cm/20" to avoid interference.
b
Do not place the transmitter close to metal objects such as
shelf bars, reinforced concrete walls, etc. as this can
decrease the transmitter's range.
Putting the Set 860 into operation
Set 860 | 9