View Full Version : Mic Interference


Gary Randall
April 28th, 2009, 11:58 AM
I am using the Senn ew100 G2 mic system to shoot weddings. The last 2 weddings I have shot have been awful. I have been getting a lot of interference and noise. The last wedding was outside in the back of a hotel. Nothing else around. I have tried changing Feq’s, but it did not help. I am also running the receiver through a small 3 channel mixer. But I don’t think that is a problem. I was using my Sony VX2100 to shoot the wedding. I have the mic on the groom
Can someone tell me if there is something else I can check and maybe some good settings for this mic? I use the mic only for weddings

Thanks
Gary

Don Bloom
April 28th, 2009, 12:30 PM
you must eliminate the possible causes 1 at a time. First eliminate the mixer, go straight into the camera, then try different settings on the camera then the wireless system. Different levels, different freqs,etc. Anything you can think of that might cause interference but remember what you did and where the settings were before so you can go back to the last one just in case. Lastly add the mixer back in and start from scratch with that.
You might want to write everything down as you go, take your time and try every combination you can until you either eliminate the problem OR you find you can't get it gone at all. Then we'll try something else.
Good luck

Gary Randall
April 28th, 2009, 12:51 PM
Thanks Don, Another quick question. I used the same mic's about 2 years ago (My churches) and the Feq's were in the 600 range and I never had any problems. Now I have the new set (my own) and my freq's only go up 500 range. Right now it is set at 520.950 does this matter at all?

Mark Boyer
April 28th, 2009, 01:20 PM
You are getting RF interference, CB radio, TV/Radio broadcast tower, cell phones, wireless internet, digital broadcasts, Nintendo DS... the possibilities are endless. The UHF band used to be the clearer frequency but now VHF is cleaner. My only suggestion is a hidden Shotgun mic hidden near where the couple will take the vows. I mount one on a boom mic stand and run a long XLR cord to the mixer. Also go to the Lectrosonics web site, search for the TV broadcasts for your area.

http://www.lectrosonics.com/service/tvlookup/tvstationlookup.htm

Jay Massengill
April 28th, 2009, 02:14 PM
How are you connecting between the mini mixer and the camera? Another possibility of interference is the Sony "Plug-In" Power that's on the mini-jack mic input of the camera.
Wireless receivers like the Sennheiser are designed to be immune to this if connected directly to the camera, but other devices (like the mini mixer) with simple adapter cables often have noise because of this voltage on the camera input.
Another possibility is the cable between the lav element and the transmitter. They receive a lot of abuse just in normal situations and can become noisy.

Don Palomaki
April 29th, 2009, 04:39 AM
can you post a sample of the sound you are getting the shows the interference?

Greg Bellotte
April 29th, 2009, 10:39 AM
Right now it is set at 520.950 does this matter at all?

Yes, frequency selection is THE thing with wireless. First research what is legally in the air. Try this website-http://74.205.3.123/ff/. Putting in Hampton, VA finds that CH22 (518-524) is an occupied station. CH26 (542-548) is listed as vacant so I would stay in that window for starters. Next thing to do is check for open channels while your transmitter is turned off. You are checking for open channels, why? Just because the FCC says there isn't anything in the air on a certain frequency doesn't mean that someone isn't using it, illegally or otherwise. And TV stations can broadcast up to 70 miles from their antenna, interference can come from a LONG way away. An open channel will show ZERO bars of RF, and the green "RF" LED should not be on. If you get any bars or a light, then something is on that frequency and will interfere with your transmitter when you turn it on.

An open channel makes all the difference in the world. After finding one, fire up your transmitter and try listening to the receiver right from the output jack-plug your iPod earbuds in here and listen in the left earbud (adjust the AF out menu up to +12 if you cant hear anything). If you hear interference noises here, try yet another channel until you get clean audio. If the audio is clean you can look elsewhere for your problem.

Also make sure you have a good level set on the transmitter. When speaking into the mic occurs, you should have about four or five bars lit on the AF meter of both transmitter and receiver. If you only have one (or none) then the level will be too low and quality suffers. If you light all seven bars and the Peak LED you will get distortion.

Hope this helps...