Wireless System Interference

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Related to Sennheiser Pro products

It is likely that the noise/static/interference you’re experiencing is being caused by a background RF signal from an external source (i.e., broadcast TV or radio stations, other wireless microphones, etc.) on the same frequency as your wireless system.

This can be confirmed by turning off the transmitter and checking the receiver’s display. If there is an RF signal showing on the receiver's display when the transmitter is off, that indicates that the receiver is picking up an RF signal from an external source and the receiver is trying to tune this external RF signal which will sound like a broad white noise.

One of the most important steps for proper setup is turning on the receiver first and checking what it sees in the absence of your microphone signal. If the receiver sees an RF signal being generated by an outside source (i.e., noise), then you need to retune the system. Depending on which system is being used, the exact steps on how to change frequencies will vary. NOTE: When using multiple wireless systems, the frequencies need to be coordinated together to ensure that they do not interfere with each other.

Once a new frequency is selected, get back to the receiver's main display. If there is no RF registering, then this new frequency is a "clean" frequency on which to operate.

Keep in mind the RF environment changes from location to location, so it is important to always check the receiver for RF levels before turning on the transmitter. It is best practice to always do a frequency scan when using equipment in a new location.

The RF environment is often constantly changing, so a frequency scan is really only completely accurate for the exact time the frequency scan is done (i.e., a frequency scan done on Wednesday night could yield different results to a frequency scan done on Sunday morning). Ultimately to ensure a frequency scan is still valid, you want to turn on the receivers and leave the microphones off. In this state, the receivers should be showing no RF signal to indicate that they are on a clean, usable frequency. If you turn on the receivers (with the microphones off) and you see a lot of RF activity, that indicates that something in the RF environment has changed. Now the frequency which was previously "clean" (and hence usable) is now "dirty" (i.e. there is an external RF signal on it), and you will need to set the receiver to use a different frequency.

PERFORM AN EASY SETUP SCAN ·Turn on your receiver (please leave the transmitter turned off). ·Hit the SET button on your receiver to enter the menus. ·Use the arrows to find SQUELCH. Hit SET and adjust Squelch to LOW. Hit the SET button to store this setting. ·Use the arrow buttons to scroll down to EASY SETUP. Hit SET, which brings you into the Easy Setup menu. ·Use the arrow keys to scroll down to SCAN NEW LIST. Hit the SET button to start the scan. You'll now see a progress bar on your screen as your receiver scans through all possible frequencies and looks for those with low background noise.

·When the scan completes, hit SET two times to accept its recommended bank # and channel #. Your display will say “Stored.”

·Turn on your mic or body pack transmitter unit and set it to the same bank # and channel # as your receiver by using the "Frequency presets" menu.

·If you own "G3" wireless equipment, you could also create the link by holding your transmitter about 3 or 4 inches away from the faceplate of your receiver and then hitting the "SYNC" button. If done correctly, the receiver screen will show a checkmark, and the 2 units will then reflect the same bank, channel, and MHz numbers. The receiver will suddenly show full reception since it now detects your transmitter.

·If you are in a challenging RF environment and your system reports 0 frequencies free, bump the Squelch setting back up to Medium and rescan.   ·If you have multiple systems to set up, make sure that you select whatever "bank" had the most "free frequencies" available after completing your scan.

·Most Sennheiser systems are sold in either the "A", "G", or "B" frequency groups so if all of your systems are in the same band/group, then you will only need to perform a scan once and set all systems into the same bank but on different frequencies in that bank.

· Let's say you have 2 systems in the "A" band and 2 more systems in the "B" band. You will need to perform a scan on one of the "A" units and then set both units onto the same open bank while then performing a new scan for the "B" equipment and setting those 2 units into their own open bank.

·Try to keep equipment of the same frequency "band" all in the same frequency "bank" for the best results. We have spaced out all of the frequencies inside each bank perfectly so that multiple systems won't interfere with each other. ·It is ideal for you to perform a new scan whenever you change venues or locations, as each spot on the globe could have different RF conditions.


  • This check can only be performed before your transmitter (body pack or wireless mic) has been synched to your receiver. Once your transmitter has been synched properly, the RF meter on the receiver will be full to the top which indicates that you have a good connection between your mic/body pack and your receiving unit.

- If you have not yet synced your transmitter to your receiver, then you may briefly tap the ON/OFF button on your receiver. Tapping the ON/OFF will function as an "escape" and bring you back to the receiver's main display. If your unit says "Mute" and you see little to no RF on the meters, you've found a clean frequency on which to operate and may now proceed with synching your transmitter.

FOR MULTIPLE SYSTEMS Use the FREQUENCY PRESET menu to set any additional systems into the same bank #, but to different channel #'s. The banks are sets of coordinated frequencies that we have calculated to work well together. All systems in the same frequency range should be operating in the same bank of preset frequencies to ensure the best performance. - Keep in mind, background noise changes as you move to new locations, so always check your receiver before turning on the transmitter. You may need to perform a fresh scan at each new location to make sure you're using the most reliable frequency for your wireless mics.

- Return the squelch setting to medium on all receivers once your scanning and setup is done.