Top 10 Frequently Asked Questions

1. Why do wireless mics drop out?

   After setting up your wireless microphone, there are a few reasons why a wireless mic may drop out.

   • Loss of range: There is too much competition from local interference, from things like TV stations, motors, LED lighting, anything with a computer chip, or cell phone service in the 600 MHz bands. This can be mitigated using directional antennas, bandpass filters, and high-quality coax cables.
   • Multipath interference: This is caused by reflections of the transmitter's signal, like metal objects in the venue. The reflections can flip polarity and cancel out the receiver's antennas.

   Our patented Diversity Fin antenna solves the distance problem by being co-located, while orthogonally mounted elements eliminate cross-polarization fades. Not only is it more convenient, it doesn't drop out!

   Further reading:

   Keeping Wireless on the Air

   Webinar – Why Mics Dropout

   Antenna Polarization Basics

   Bandpass Filter Basics

   Diversity Fin Whitepaper

2. What is the range of my system?

   Typically, the range for unlicensed wireless mics is about 300 ft. However, this range depends on if the signal is compromised by local interference. If you need a larger range, you can try switching to an antenna with more gain or a coax cable with less loss. Antenna booster amplifiers do not increase range, even if they are advertised to do so.

   RF Venue Performance Calculator

   Link Budget Basics
   
   Antenna Gain

   How to Do a Link Budget

3. Can I mix RF Venue products with other brands?

   Yes! Wireless microphone systems, distro systems, antennas, and coax cables from almost every brand and be used together so long as they operate in the same frequency range and within the rated power levels. You can easily add an RF Venue distro to an existing distro system from another manufacturer.

4. What frequencies are legal for unlicensed users as of July 2020?

   Since July 3, 2020, the 470-608 MHz and 614-616 MHz bands and a portion of the MHz duplex gap (657-663 MHz) are legal for unlicensed users. You can also use the 902-928 MHz ISM band, the 1920-1930 MHz band, and portions of the 2.4 GHz and 5 GHz ISM bands under specified power levels and rules for operation for each band. In addition, the VHF frequency range for wireless microphones of 168-216 MHz is available.

   If you have a wireless system that can tune outside of those frequencies, even if you do not tune your mic to them, they have been decertified for legal use in the USA. You can check with your wireless microphone manufacturer to see if your decertified systems can be updated.

   FCC Wireless Mic Rules:

5. Why do I get noise after the transmitter is turned off?

   Many wireless mics have a "squelch" system to aid in the reduction of unwanted noise when using an analog wireless microphone. When you turn off the transmitter, the squelch pilot tone stops transmitting to the receiver, making it increase its range to look for a new signal. Inevitably, the receiver will find interference, and since it is not being muted by the squelch tone, the noise is passed into your audio system.

   Squelch Basics  

   How to Adjust Squelch

6. How do I pick the best channels?

   One of the most important steps for ensuring reliable system performance is to select the best possible combination of channels for your wireless mics and IEMs. The number of available frequencies begins to drop as you add more devices to your system.

   Many wireless audio systems have automatic channel finders, but if you are using IEMs and mics together, these might not work. The gold standard is to use an RF scanner and insert the data collected from it into an RF coordination program — many manufacturers have a free version. These programs can often use wireless receivers as input, but receivers can only see the frequency range they can be tuned to.

   Scanning for Coordination

7. How should I aim my antenna?

   Proper antenna aiming can be highly beneficial to the quality of your audio. Omni antennas, such as the whips that are provided with a new wireless microphone, pick up in a 360° horizontal circle, so they cannot be aimed. They provide low gain and no rejection of local interference.

   Directional antennas (paddles and helical) provide additional range and typically reject 50% or more of local interference. The horizontal coverage angle of directional antennas is what you need to consider when aiming antennas. Visualize a triangle with the pattern of the antenna and lay that over the floor plan to include every position you need to fully cover your event.

   Antenna Placement Webinar 

   Scanning for Antenna Positioning

8. How far apart must I place the antennas?

   Except for our Diversity Fins, which can have co-located antennas, having the signal overlap in an area, antennas need to be a minimum of a quarter wavelength — six inches — away from each other, though they do better at two wavelengths, or 44 inches, apart. It may not seem intuitive, but some of the power received by your antenna gets reflected (VSWR or return loss) out from the receiver and back into the receiver's antenna, where it now becomes a transmitter. If one antenna is within about 6" of another antenna, their signals will imprint onto each other, causing interference.

   Keeping Wireless On The Air  

   Avoiding Antenna Farms

9. Will my system work?

   How will you know if your model wireless system connected to your antenna with your coax cable lengths will reliably perform in your venue? You can plug in some specs to our Link Budget Calculator to give you a pretty reliable answer. Basically, you add all the gains and subtract all the loss figures (in dB) and hopefully end up with a number that is at least 20 dB above the number (in dB) for your local noise floor.

   RF Venue Performance Calculator

   Link Budget How-to

10. What are the best practices for IEM systems?

    For the best performance and easiest setup, when using multiple channels of IEM they should be connected to a combiner and then retransmitted via a single helical antenna using the lowest gain setting that reliably works on your transmitters. The use of  multiple transmitting antennas on multiple transmitters almost always results in signal degradation. We recommend feeding no more than eight transmitters into a single combiner system as exceeding that number rapidly increases the probability of IM (intermodulation) interference and results in the likely reduction of possible open channels for both your mics and ears.

    Helical antennas are overwhelmingly the antenna of choice for IEM transmission because the circular motion of the RF field emitted distributes the signal through all possible polarization angles. This removes the greatest risk of dropouts, as most IEM belt packs are limited to a single whip antenna.

    Using Mics and Ears Together Strategy

    IEM Combiner