Generally speaking, a professional wireless microphone system consists of 3 main parts: an input source, a transmitter, and a receiver. The input source provides an audio signal to the transmitter. The transmitter converts the audio signal to a radio signal and transmits it to its surroundings. Then the receiver receives the radio signal and converts it back into an audio signal. This is a complete process that makes the said parts a microphone wireless system. Other system components possibly may include antennas and distribution systems.
The process and the basic components are functionally similar to radio communications. What differs is the component size and the physical system setups.
Basically, there are 4 wireless microphone system setups. They are about the mobility of the transmitter and receiver and are for different uses.
1. Standard “wireless microphone system” comprised of portable transmitter & stationary receiver: The transmitter is always held by the user who is free to walk around, while the receiver is settled in a certain position such as a camera. The input source in this setup is usually a microphone. The receiver output then is sent to a sound system or recording equipment. This is the arrangement widely suitable for live streaming, public speaking, and broadcasting.
2. “Wireless system” using stationary transmitter & portable receiver: Opposite to the standard configuration, the user carries the wireless microphone receiver, while the transmitter is fixed. The input source which is connected to the transmitter for this setup is often a sound system, playback system, or other installed source. The output of the receiver in this case is always monitored using headphones or loudspeakers. This wireless mic system is built for in-ear monitoring, simultaneous interpreting, and instructional uses.
3. “Wireless intercoms” system carrying portable transmitter & receiver: Each component user has the freedom to move about. In this setup, the input source again is usually a microphone and the output a headphone. Each user has both a transmitter and a receiver for two-way communication. It is also used to transmit audio from a professional wireless microphone to a portable camera/recorder for broadcasting, filming, and video making.
4. “Point-to-point” wireless system holding stationary transmitter & receiver: Typically, the input source would be a playback or mixer while the receiver output might be a sound system or broadcasting facility. Typical examples of this professional wireless microphone system may be commercial and non-commercial broadcasts from fixed transmitters to fixed receivers.
UHF that is the band of 400MHz at least has been the standard operation frequency for microphone wireless for years and has always provided the strongest and best performance. Though the FCC has issued policies to limit the frequencies of operation for UHF wireless microphone system, the wireless frequencies can still vary. The best combination of long transmission distance and clear frequencies is between 470-548Mhz bands.
The new 2.4 GHz band which is said to challenge the UHF band, is also seen in a number of best wireless microphone systems. You should be aware that the 2.4GHz frequency band is a kind of unlicensed band similar to the WiFi and is potentially subject to interference from microwave ovens. Its operating range is also much shorter. Please use a 2.4GHz digital wireless microphone in a smaller room with no obstructions between the transmitter and receiver antennas.
If you would like to find out more differences between UHF and 2.4 GHz wireless microphone system, see Wireless microphone systems: UHF or 2.4 GHz?
Professional wireless microphone system features
1. Separate “Mute” and “Power” switches
This is one of the top requests found in the wireless mic system reviews. It is the function to make sure that the receiver and transmitter are locked on the same frequency when they are talking to each other, and that nothing can get into that system, except another system on the same frequency.
The separate “Mute” switch allows a speaker to mute his/her audio signal if he/she does not want to be heard.
2. Low impedance, balanced line output
The best wireless microphones system have balanced outputs from the receiver to connect directly to the mixing console. Such connections cut down on or phase out noise and hum problems caused by audio signal.
3. Rechargeable batteries
Newer professional wireless microphone systems are launched to have long-working rechargeable batteries that last 8-10 hours on one charge. Additional functions such as selectable High/Low signal strength may be added to help save the battery power for the portable wireless microphone system, and accessories like quick charger would be accompanied to save your time in powering the device.