# Help choosing frequencies to use for wireless mic’s



## amonthofsundays (Feb 7, 2009)

I've got to be honest I've been using wireless mic's at my high school for four years with a lot of luck but knowing really nothing about the frequencies they were operating on. Now that I’m moving to another theater and have to expand my system and the more I try to learn about them the more confused I get. I understand the whole DTV transition puts the 700mhz band off limits but I don’t know where to go from there. As a recall, my eight channel sennheiser g2 setup had frequencies operating in both the 300mhz and 500mhz range. I'm located in Los Angeles and I know it varies by market but I have no idea what the whole A block C block thing is about and how you would find out which would be best. I already checked out the sticky wireless mic FAQ and I couldn’t discern a clear answer to this. A link to a tutorial or a simple explanation would be greatly appreciated. Thanks.


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## rwhealey (Feb 7, 2009)

Both Sennheieser and Shure have frequency finders on thier websites:

Sennheiser USA - Frequency Finder

and 

Shure - Wireless Frequency Finder

You select the type of wireless that you're using and it'll show you what frequencies are recommended and where the TV stations are that you should avoid.

I just discovered, through the Shure finder, that some of our mics that had been giving us bad performance were on frequencies that intersected with a local TV station.


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## ScottT (Feb 7, 2009)

I would look at this:
Shure - Wireless Frequency Finder
It will tell you what groups and channels you should use. I know that it does not explain why but it will help you decide which channels to use. Also, introduce yourself over on the New Members Board.

EDIT: Dang rwhealey you beat me to it.


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## amonthofsundays (Feb 7, 2009)

Thanks for the speedy reply. That is a good resource I overlooked on the sennheiser website. Another possibly stupid question though. Why do none of these charts list the lower channels 2-13?

EDIT: does that mean the lower channels are operating in VHF?


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## waynehoskins (Feb 7, 2009)

Yep, channels 2 through 13 are in VHF spectrum. VHF is 30-300 MHz, UHF is 300 MHz - 3 GHz.


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## mbenonis (Feb 8, 2009)

amonthofsundays said:


> I've got to be honest I've been using wireless mic's at my high school for four years with a lot of luck but knowing really nothing about the frequencies they were operating on. Now that I’m moving to another theater and have to expand my system and the more I try to learn about them the more confused I get. I understand the whole DTV transition puts the 700mhz band off limits but I don’t know where to go from there. As a recall, my eight channel sennheiser g2 setup had frequencies operating in both the 300mhz and 500mhz range. I'm located in Los Angeles and I know it varies by market but I have no idea what the whole A block C block thing is about and how you would find out which would be best. I already checked out the sticky wireless mic FAQ and I couldn’t discern a clear answer to this. A link to a tutorial or a simple explanation would be greatly appreciated. Thanks.



Welcome to CB!

Read over my wireless FAQ (sticky thread in the Sound forum) if you haven't already. 

As far as block designations, it varies from manufacturer to manufacturer. You want to find whatever block has less TV stations in it. Now, since you're in/near LA you're probably not going to have too much luck with it to begin with (sorry!). But that doesn't mean you can't be creative.

So, what to do. Determine what frequency range each system operates in (it should be printed on the back of each transmitter or receiver). Then, go to the frequency finder pages above and see if you can find enough frequencies that are clear to use. If not - come back here and let us know. There are more creative ways of making it work.

Mike


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## Anonymous067 (Feb 12, 2009)

See my posts in this forum.

http://www.controlbooth.com/forums/sound/11190-frequency-evaluation.html


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