5
Adjustments when used with loop amplifier
Please note that the difference in sensitivity for handheld microphones (EJ-701TM Plus)
and pocket transmitters. The handheld microphone is set to a lower level to avoid feedback
when used in front of speakers. Due to this the adjustments have to be made in the
following order:
1. Set the sensitivity of the handheld microphone to ”HI”.
2. Set the volume control of the corresponding diversity receiver module to maximum.
3. Adjust the input level of the loop amplifier by turning the corresponding potentiometer
until the IN led lights up distinctively at the peaks of the program signal source (AGC
knee). Do not turn it up more than necessary as this will increase the risk of distorsion.
4. Increase the loop current trimmer to reach correct level in accordance with
IEC-60118-4 (0dB at peaks of the program signal source).
5. The steps above secures a correct adjustment of the handheld microphone.
6. Adjust the sensitivity of the pocket transmitter to ”LOW”.
7. Set the volume control of the corresponding diversity receiver module to approximately
“12 o’clock”.
8. If user experiences the level of the pocket transmitter to be too low: Start to adjust the
volume level of the corresponding diversity receiver module. If still too low, adjust the
sensitivity of the pocket transmitter to “MID”.
Acoustic amplification with an active speaker
In rooms without a loudspeaker system, it may be advisable to use a portable, active
speaker with built-in wireless receivers to also acoustically enhance the sound. A slight
acoustic amplification is often welcomed even in smaller rooms, especially when listening
for a long period of time, and it is perceived to be more natural by both lecturers and
listeners that the sound is acoustically amplified when speaking in microphones.
The Okayo GPA-670BD1 is a small, light-weight and flexible active speaker (with built-in
amplifier) especially suitable for enhanced speech intelligibility. The GPA-670BD1 has
rechargeable lithium ion batteries that provide 4-6 hours of operation, but can also be used
connected to a wall outlet. The speaker has the same type of dual wireless receiver module
that is built-in to the diversity receiver in the P-Loop case. This means that the sound from
the wireless microphones is transmitted simultaneously to the loop and the loudspeaker.
No cable or connection is necessary.
