sennheiser wireless microphone interference with EX1

[Joe Spitzer]

posted this in the audio forum, but thought ex1 owners might have some insight in case it does have something to do with the camera setup

Hello, I searched the forums and couldn't find what I was looking for, so i'm posting here. Basically, I'm having issues with my Sennheiser ew100 wireless microphone system. My range is super limited, like 10 feet, and even within that range I get little bursts of static a fair amount of the time (although not always). I actually have access to two ew100 systems, and I get this with both of them, so I'm thinking it has something to do with my setup, or perhaps some settings. Anyway, this is how I have my EX1 set up usually -

Channel 1, set to mic input, the wireless receiver plugged in, mounted on a hot shoe near the back of the camera.

Channel 2, set to mic + 48hz (or whatever the measurement unit is), with my Rode NTG-1 shotgun plugged into that, taking power from the camera.


I've tried changing frequencies, but that hasn't helped. Movement seems to exacerbate the problem, and I could be imagining that. I believe the 5 reception bars usually drop to 4 on the receiver whenever there's one of the static bursts. Thanks for any help anyone might be able to provide. This problem has been haunting me!

[Dave Morrison]

What frequency block is your EW100 using? A, B, or C?

[Barry J. Anwender]

So when you say two EW100 systems, does that mean two different receivers and two different transmitters? If that is the case, then it sounds like a case of interference from an external source, especially when it varies as you move around. Some of the frequency options that Sennheiser provides are in the Off-Air Television frequency bands, so there could be overlap from a local TV station.

The RF interference could also be intermodulation and/or spurious harmonics from two nearby transmitters that are close in frequency. External sources of RF interference are not always very easy to pin-point.

As suggested above, try setting your wireless frequency to completely different bands i.e. A, B, C. That should allow you to rule out external sources of RF interference. Good luck.

[Dave Morrison]

Actually, my question about the frequency blocks has more to do with what else might be interfering with his signal in his area. I can't tell from his description whether this is a new Senn set or whether it's a new problem with an older set. When analog TV stations went off the air, some of the frequencies were reallocated and some older wireless systems may not work properly. My Senns are on the "B" block of frequencies (626 MHz to 662 MHz) so luckily I didn't have any issues after the changeover. Here's a link to the FCC page: Operation of Wireless Mics in 700 MHz Band

Of course, this might be a worthless discussion if it's just a defective wireless set, but it sounds like it's acting up across a couple xmitters.