A TE30 does not generate noises when it is connected
to an external audio mixer. After the TE30 joins the conference, background
noise and current noise are generated.
1. Connect the microphone directly to the TE30 to
check whether there is background noise or current noise. If there is no noise,
the problem is caused by the cable or audio mixer.
2. Check whether the TE30, audio mixer, and microphone
are grounded together.
If devices are not grounded together, the common-mode
interference cannot be effectively eliminated.
Make sure that the microphone, audio mixer, and TE30
are grounded together. After the change of grounding, noises disappear.