Wireless mics, and their close relatives, wireless IEMs (in Ear Monitors) are complex, interdependent, location-sensitive, self-contained little radio stations. They transmit on RF (Radio Frequencies) through the air with weak carrier signals beset by gaggles of stronger, more numerous competitors vying for airwave space. Getting them to work consistently is difficult at best, but, since singers and speakers demand their inclusion, let’s look at how we can give our wireless a fighting chance in the wild.
Most wireless mic and IEM systems work in the UHF range, typically between 470 and 608 MHz after the latest FCC auction sold away most of 608-698 MHz and we had already lost 698-806 MHz previously. Unfortunately, as the space for wireless mics has shrunk, we have seen a dynamic increase in the demand for wireless systems. There is no cheap solution to packing dozens of mics into a crowded RF arena. In other words, high quality wireless systems are the only choice, and they cost real money. So, the “Four wireless for $199” deals are guaranteed not to work in any situation outside a corn field in Nebraska. What, then, is the best way to allocate limited resources for wireless? Here are some ideas.
Use wireless only when required. If the worship leader is at a grand piano and does not get up and move around, use a wired mic. Despite the “clean stage” theory, a mic cable is drastically less noticeable than a wireless mic reproducing interference at full level. Each wireless not used means more space for those in use, since every wireless produces not only its fundamental frequency, but several harmonic frequencies based on that fundamental. Just as striking A440 on a piano creates multiple harmonics within the instrument, so too, wireless mics have spikes all along the RF spectrum. When several mics are in simultaneous use, these harmonics can interfere with one another and cause havoc. This is why manufacturers pre-select groups of compatible frequencies within each band.
Purchase the best wireless the church can afford for the pastor. The one non-negotiable wireless is the pastor’s. This unit should be the best available with the highest reliability, such as Shure UHF-R on the analog side and Sennheiser 6000 Series in the digital realm. As part of the package, select a high-quality ear-set mic, such as the DPA d:fine 4066 series. The reliability and sound quality difference versus a low-cost mic is significant, and replacement parts are readily available.
Obtain a distribution system. Antenna farms are an invitation for poor RF performance. RF Venue makes excellent, reasonably priced units like the Distro4-Bundle, which handles four diversity receivers from one paddle antenna and includes all the necessary cabling. Their Combine4-Bundle does the same thing for inherently more complex wireless IEM systems. RF Venue products are designed to work with any manufacturer’s systems.
Budget for maintenance. Wireless mics are fragile and cannot be dropped or abused without damage. Figure on sending transmitters in for factory service once every two years on average, based on typical usage. Buy good batteries such as Duracell Pro Cells and change them out after two hours use. It is a small price to pay for reliable performance. Keep a spare head, such as an SM58 on-hand in case someone drops a mic during sound check. Finally, use Micro-Phome sanitizer on all mic elements on a regular basis to prevent the spread of germs.
Wireless mic and IEM systems provide freedom of movement, but at a price. If the price is worthwhile, the results can be solid, repeatable performance for years to come.