Sennheiser ew 300 IEM, Instruction Manual

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9 Overview
Wireless transmission systems
With the evolution wireless series, Sennheiser puts an end to cable tangles
and enables complete freedom of movement at an affordable price.
The systems operate exclusively in the UHF band. UHF transmission is
extremely reliable and is far less prone to interference than the overcrowded
VHF band – harmonics from mains units, fluorescent tubes, refrigerators,
computers, etc. are virtually eliminated. Also indoor propagation of UHF
radio waves is better than VHF so that the RF power can be kept low – this
is also an advantage when using multi-channel systems. Finally, UHF
frequency ranges are being approved all over the world for radiomicrophone
usage – in some countries licence-free.
Fresh batteries ensure good reception during operation. Always use alkaline
batteries for best operation – a 9 V PP3 battery has a much longer operating
time than a NiCd rechargeable battery (approx. 4 to 6 hours with a 9 V PP3
or 1 hour with a rechargeable).
Correct adjustment of transmitter sensitivity is vital. Too high and you get
overmodulation and distortion, too low and you get undermodulation and a
noisy signal. Please set the sensitivity correctly for the microphone/usage
and check it before every performance to ensure best operation.
Interference such as distortion, hissing or “birdying” may occur if several
transmitters are used together and the frequencies have not been correctly
chosen. Sennheiser standard frequencies (as supplied) are all intermodulation-
free. For other frequency sets please contact your local Sennheiser agent,
who will be able to provide you with information on correct frequency choice
and/or be able to calculate special frequency sets for you.