Wireless microphones have become very popular in the last few years. Not just with musical performers but with business conferences, television news, church services, and other venues.
The main reason is it eliminates the microphone cable connection. This frees up the speaker to walk across the stage, among the audience, or even out the door. Sometimes. Greater mobility and flexibility for the presenter gives him the ability to talk with his hands.
A wireless microphones system is great to have but can be a bit challenging to use. There are legal issues as well as system quirks. Here are a few things you should know before the purchase and installation of a wireless microphones system.
We know a microphone needs a PA(Public Address) system to plug into. An amplifier needs a speaker to make sound. Different sound systems fit different applications.
Sounds simple but without any guidance, getting a good or even functional sounding microphone system can be a confusing task. Let’s look at some of the most common sources of confusion that non-engineers encounter.
There are three discreet components in a functional wireless microphones systems:
1. A Microphone 2. A Transmitter 3. A Receiver
The microphone is the component the user speaks or sings into. The sound waves are converted into electrical impulses. These impulses are amplified so listeners can hear them.
The transmitter is usually built into the body of a handheld microphone. With a hands-free microphone like a headset or lavaliere, the transmitter is usually a pack the user wears on his belt.
The receiver takes the broadcasts from the transmitter and changes the radio waves back into an electrical signal. It is then passed to the sound system.
A wireless microphones system will not work without any one of these components.
The Total Package
There is a very good reason a wireless microphones system is sold in a package. Different manufacturers of microphones, receivers, and transmitters are often not compatible. Sometimes even a different receiver from the same manufacturer will not be compatible.
The receiver and transmitter broadcast on a specific frequency. A receiver operating on one frequency won’t work with a transmitter operating on another. Frequencies are often not adjustable by the user.
Finding compatible transmitters and receivers from different manufacturers is a tricky endeavor. This is best left to professional sound engineers. So the easiest way to insure compatibility is to stick with the receiver that is recommended for the transmitter. In other words, just buy the complete package.
One Mic – One Receiver – One Transmitter
The audio novice may think that once he has a receiver and compatible components, he can just buy a bunch of microphones and use them at the same time. This will not work.
Each microphone needs a dedicated transmitter. Each transmitter must broadcast at a different frequency in order to work alongside others. You will need a different receiver, tuned correctly, to use each microphone. So, the more microphones you have the more expensive your system will be.
Fortunately, many manufacturers have multi-microphone systems that are affordable for beginners.
What’s My Frequency?
Another Important piece of information to know about a wireless microphones system is the use of the correct frequency. You want to make sure you are using the appropriate frequency to not break any FCC(Federal Communications Commission) laws.
The entire 698-806 MHz UHF(Ultra High Frequency) was reallocated by the FCC in 2010. This frequency range is for emergency responders and wireless devices such smart phones.
Any wireless microphones system that operated in this bandwidth was forced to vacate the frequencies. This was in compliance with the law, Many microphone system users had to reinvest in new equipment. To add to the problem the lower UHF frequencies were now being overcrowded.
Now users want to know: What frequencies can I legally use?
Intercom systems, monitoring, and unlicensed wireless microphones are allowed to use any VHF(Very High Frequency) or UHF band not in the restricted bandwidth. The frequency cannot already be claimed by a local TV station or public safety agency.
The geo-location database should be checked by wireless operators who need to deploy numerous systems. This is to make sure that they don’t interfere with existing systems when planning large events.
If your microphone system operates on the VHF bandwidth or UHF outside of 698-806 MHz then you are fine. Operating in forbidden frequency range could garner a penalty of equipment confiscation. You could also be looking at a large fine in the $10000 range.
Chances of getting caught are actually slim, but the potential financial liability had users getting rid of their old mic systems. Better to just spend money on FCC compliant systems, than to run the risk of a heavy fine.
The government has proposed an additional spectrum reallocation. This would free up an additional 500 MHz of bandwidth to be auctioned off by the FCC to the highest bidder.
Time to Get That System
So, lots of things to think about. You may have just wanted to get a wireless microphones system for a small project. Now you may need multiple systems for multiple microphones, and have to worry about being on forbidden frequencies.
Dealing with a wireless microphones system is not as easy as you may have first thought. But after a little education you will realize it’s not that hard either. Just shop around for the best valued system. The system should tell you what frequency range to use. Check your geo-location database to make sure you are not using an illegal frequency.
Now, go have some fun with the freedom of a wireless microphones system!