Wireless microphones let performers move freely onstage, unrestricted by cables. Musicians, teachers, corporate meeting spaces, and houses of worship can all benefit from the freedom of a wireless microphone system. If you're thinking about adding a wireless system to your school, theatre, or karaoke bar, this wireless microphone buying guide can help you find the system that's right for you.
The Basics -- Transmitters and Receivers:
Every wireless mic system has two components: a transmitter, typically worn or held by the performer -- and a receiver, which collects the radio signal from the transmitter, converts it to audio, and sends the audio through a cable to your mixer or power amp. We've organized this buying guide by type of transmitter: handheld microphones, lavalier/clip-on microphones, and headset microphones.
Running Multiple Simultaneous Wireless Mics:
If you plan to use several wireless microphones at the same time, each microphone must operate on a different radio frequency so their signals don't interfere. Look for frequency-agile systems, which allow you to choose from a range of frequencies to find an open channel. For two-mic setups, it's a good idea to choose a "Dual" system that's designed to run both microphones simultaneously.
VHF vs. UHF Bands:
The majority of wireless microphone systems operate in the Ultra High Frequency band, and some operate in the Very High Frequency band. While VHF systems are typically more affordable, they have fewer available channels, and must use very long antennas. UHF systems are the professional standard. Diversity receivers -- which use two independent antennas to improve reception -- are very effective in the UHF range, and UHF systems can use shorter antennas due to their shorter wavelengths (typically 400 - 698 MHz). However, the UHF spectrum has potential for interference from TV stations, and it's worth noting that the FCC plans to repurpose at least part of the 600 MHz band,
and within a few years, those frequencies may no longer be available to wireless microphones, so to be on the safe side, look for UHF systems that operate below 598 MHz. Wireless microphone manufacturers offer Frequency Finder tools to help you find clear frequencies in your local area, so use those tools before buying a UHF system to avoid UHF-TV interference.
900 MHz and 2.4 GHz Bands:
Many digital wireless microphone systems run on the 2.4 GHz ISM band (2.400 - 2.483 GHz), which offers worldwide license-free operation, and very short antennas. However, don't expect to run more than 4 to 8 digital wireless channels simultaneously -- this part of the spectrum is crowded with Wi-Fi devices, and in many corporate settings and venues where Wi-Fi is the priority, you're better off sticking with the UHF band. The 900 MHz range -- specially 902 - 928 MHz offers more channels outside of the UHF range. However, while 900 MHz wireless microphones are legal in the United States, they're not necessarily legal in all parts of the world.
Analog vs. Digital Wireless Microphones:
Digital wireless systems convert audio to a digital signal before sending it through the air. High-quality 24-bit digital wireless systems deliver extremely clear audio, with a wider dynamic range than traditional analog systems. However, since most entry-level digital systems run on the 2.4 GHz band, they offer potentially fewer simultaneous compatible channels. Analog wireless systems are still the most cost-effective choice if your channel count is in the double digits. High-end, expensive digital wireless systems, which typically run on the 900 MHz or UHF band, offer the best of both worlds -- superb audio quality, plus high channel counts.
Fixed-Frequency versus Frequency-Agile:
Fixed-frequency wireless systems are just that: they always run on one predetermined frequency band. Frequency-agile systems can hunt around for an open channel. If you're installing a wireless system in a venue, a fixed-frequency system may do the trick. But if you're planning on bringing your wireless system on the road to use in multiple venues, a frequency-agile system is more likely to work in more places.