What causes the interference?
Digital Radio Microphone transmitters can produce some RF noise which can be picked up by the connected microphone and heard within the audio signal.
Usually this occurs when an older microphone is used. Older microphones were designed with adequate screening in their design to prevent interference sources at the time. Since Digital radio-microphone transmission wasn't a concept at time older microphones were produced, shielding against these signals was not necessary.
How can I avoid such interference?
- Using newer designs of microphones usually means they are not susceptible to such interference. For example:
- The older MKH 50 may suffer this type of interference in some scenarios, whereas the newer MKH 8050 does not.
Older lapel microphones like the MKE 2 with a black serial number tag may suffer from such interference, but newer MKE microphones with a blue serial number tag are not likely to suffer interference.
2. When using classic microphones with a plug on transmitter, try to get a small amount of physical separation between the microphone and the transmitter (so putting a short cable ~50cm / 20in long and mounting the transmitter a little away from the microphone)
3. Ensure all interconnecting cables are of high quality and well shielded