Tuesday, 23 October 2012

FreqFinder - The Must Have App for Location Recordists?

Google App Store
As we all know the "App" market place - be it on Apple, Android or any other operating system - has changed our lives and the way we use (and abuse) our smart phones / tablets. There are a vast number of music related apps - especially for the Apple market, but there are not that many that are designed for the location sound recordist; which, to be fair, is not that surprising as we are a fairly niche group to say the least.

So last night I was completely taken by surprise when the forum members of the Institute of Professional Sound highlighted a absolute "Must Have" App for location sound recordists and anyone who uses radio mics on location.

Freq Finder

FreqFinder (written by New Endian) is a nicely simple app that allows the user to enter the frequencies of radio channels and check for intermodulation interference across the channels. It comes pre programmed with the pre-set frequencies of the major radio mic manufacturers (both for the US and the UK - so lectrosonics, comtek, sennheiser, Audio and Micron) and allows the user to build up their own specific list of radios and check for intermodulation across the channels.

Ch38 Micron Explorer 100
In the UK an application like this is such a power tool, as Ch38 no longer has the pre defined channel list that the JFMG had set up in CH69, so it's much more of a free for all - as each manufacturer is trying to design their kit to make the best of the limited band width (for more rantings on that particular topic have a look at one of my previous blog pages).

Frequency Tables

Using FreqFinder with my fairly modest set up of Micron and Sennheiser radio microphone channels, was really straight forward. Freqfinder has preprogrammed into it (some of) the manufactures preset frequencies, so for the Micron explorer range it has the 16 channels that are standard for the Micron Explorer 100 series.

As I have the LCD range of microns, I'm not tied into this preset frequency set, so I have my radios pre programmed to number of inter mod free frequencies - but I can programme in an equivalent table  into FreqFinder to match how I'm working - and it should make it much easier check frequencies when working with equipment from different manufacturers and other recordists.

JFMG Shared
Practical use of the app.

This is very much a "first look" at this app and I've not had time yet to use it in in the field with my radios or in difficult RF environments. But something has made me query the accuracy of the app.  The JMFG have suggested a number of frequencies for shared use in CH38 that should be intermodulation free. Putting these frequencies into FreqFinder showed that there were intermodulation 'hits' on most of the frequencies - but practically I'm not sure yet what this means. When I get chance (probably later this week) I'll try and actually use the app in conjunction with my radio mics and see exactly what the practical implications of the information that it presents.

For those of us in the UK, be aware though that the TV channel number refer to the USA frequencies...so it can be a little confusing! The App costs £18.99, and may seem expensive, but I think the capabilities of a tool like this make it a price certainly worth paying.

23rd October 2012



  1. Hi Grant,
    Thank you for reviewing my app. I can explain the difference between FreqFinder's calculations and the JMFG 10-channel plan.

    The JMFG list actually does show what FreqFinder calls "Hits". The "25k0", "50k0", "100k0" numbers are the count of intermod products that are near the transmitting frequency.

    The only intermod products that the JMFG list accounts for are 3rd Order products. FreqFinder by default calculates up to 7th order products for 2 transmitter combinations.

    Also in FreqFinder, the higher the product's order and the more transmitters involved in the product, the closer it has to be to the transmitter frequency to be considered a hit. Which is why some of the "100k0" hits are not shown in FreqFinder.

    All in all, FreqFinder's results tend to be safer than most lists. But that does come at the cost of compatible channels per block.

    Please feel free to contact me about any comments, questions, or suggestions you have about the app.


    1. James,

      Thanks for your comments and explanation - that make more sense; It's certainly a great app.. I'm still in the process of writing up a fuller review - but I've been very busy work wise at the moment. Would it be okay for me to email my thoughts....but then I know you are busy updating at the moment, as I've had about 2 updates in 2 weeks.



    2. By all means: newendian@gmail.com