“Our band runs all wireless on stage, which up until now has worked pretty well. I recently purchased an additional wireless for a flute mic we’re adding to the show and it interferes with other channels of our system, even though it’s on a unique channel. After going through several different channels I’ve figured out that there are no more channels available on the system I use that don’t have problems. Why do so few of the channels work?”
There are two common things that interfere with most wireless systems we use: TV stations and other wireless systems. Assuming you don’t travel around much you can pretty well nail down the problem frequencies due to TV stations. Interference from other wireless systems, however, is a much more difficult problem.
This problem stems from the fact that even though your wireless system may be set to a particular frequency it still radiates energy at other frequencies. These additional “sideband” frequencies can interact with other sideband frequencies from other wireless units to produce new spurious frequencies that can potentially interfere with a third wireless device, which may be compatible with any one of the others by themselves. This type of transmission interference can be very complex to figure out, but it is all predictable. Before placing more than three or four wireless units in the same environment you should contact the manufacturer to go over these details and make sure you are getting into a system you really will be able to grow with. They can often work out a plan for you of each specific frequency you should buy to best minimize problems.
So long as you stay within the same brand and type of wireless they are generally set up so all of their “channels” can be used together in an environment, but it’s still a good idea to check and make sure. Two elements that can throw a monkey wrench into this are: the introduction of other brands or types of wireless systems (or RF transmission in general), and unpredictable behavior due to “dirty” transmitters. Yes, some wireless systems have cleaner RF outputs than others. Generally the more expensive the system the more governed they are in terms of spurious output, and this is specifically so they work better in setups where many are used.
Some of the more modern and sophisticated wireless systems can automatically set themselves up with good frequencies, which greatly minimizes these types of problems and allows the system to travel to different areas where different frequencies may be optimal. If you’re thinking about setting up a multiple wireless system contact your Sweetwater Sales Engineer. He or she can help you do it right the first time.