Power supply interferes receivers of my radio microphones!

Power supply interferes receivers of my radio microphones!

I have a case made where two Sennheiser microphones and an antenna converter are installed on the front of the Denon and below on 3U.

As soon as I turn on the Prime4, I get a full-swing interference signal on all two receivers.

When I lift the Prime4 high, the signal is gone.

How / Where do I have to do what to protect the Prime4’s (presumably) power supply?

The following things help:

  • Place aluminium foil under the Prime4
  • Turn antennas further down

The following things don’t work:

  • Change frequency at the receiver
  • Set Prime4 to another power outlet

I had a case made for 500 Euros to have the microphones in the case, it would be more than annoying if the Prime4 beamed so strongly that you can’t use Sennheiser G3 (A Band).

I am very grateful for any help!

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You forgot, that Prime 4 has also Wifi. You should keep wireless microphones away from any wifi devices. Check the info in the microphones manual.

Hi, it is not WIFI, it is the power Supply. I ve had the same problems with other equipment (DDJ-SX2/19" Player) Thomas

This should simply be enough to highlight that some equipment just isn’t supposed to be in close proximity to each other. I’ve no problem with having a mic receiver right on my prime but I have to use antenna extender cables to mount the antennas a couple of meters away

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I use a Sennheiser E945 system probably 0.5m away from my MCX8000 and get no interference from the PSU.

It is case, 10cm away :slight_smile:

Assuming you are using good quality wireless mics, the antenna’s should have a connection that you can use to take the antenna off and attach an external antenna (commonly referred to as “flag”, see picture).


So, undo the antenna’s from the units, use a high quality coaxial cable, set the flag (it can be easily screwed to the top of a microphone stand) somewhere off to the side and you should have no more interference and on top of that, as a bonus, larger range and better signal quality.

My three cents as usual

Thank you, i know that this a good solution but it is oversized for a mobile DJ :slight_smile: For the moment i gave up and put my receivers into a different case. Our music store here Thomann gave me the tip tzhat it is an EMI problem, electromagnetic radiation. There is a 1U power conditioner with an EMI filter, this COULD reduce the problem, here is a link:

I will tell you, if this solves the problem.

Further i have ordered better power supplys for the rack and new Sennheiser G4 Sets. My actual set is 5 years old, mybe the new receivers are less sensitive.

P.S. If its dont work than the case is easier to carry :slight_smile:

Since I already bring a bag with at least two speakerstands and my monitor speaker is also on a mic stand, bringing an extra one isn’t too much of a hassle. The flag fits in my DJ bag, so don’t find that too inconvenient. Especially now that, since my P4, I don’t have to bring my folding laptop stand anymore!

And as said, quality of the signal is now wonderful. I usually set it slightly behind and to the side so the cable is not in my way .

I do get that having it in a (flight)case works as well. Although that too you ideally want to place somewhere where the antennas face the crowd, preferably at ear height or above, with nothing between the antennas and the mics.

But do let us all know if the EMI filter solves your problem.