Wireless microphone systems: UHF or 2.4 GHz?

The basic components of wireless microphone systems are essentially the same: the microphone, the transmitter/transmitters that is/are built into a handheld mic or a separate bodypack unit, and the receiver with one or more antennas. The receiver’s output is always connected to the mixer.

UHF (= ultra-high frequency, 470-698 MHz TV-band) and the new-generation digital 2.4GHz are two typical types of wireless signal transmission that are applied by many microphone manufacturers to the microphone manufacturing.

Which wireless microphone system is better: UHF or 2.4 GHz?

The new 2.4 GHz wireless mic systems are supposed to challenge UHF. In fact, they are totally different and play their roles in different applications. 2.4GHz Wireless microphone systems operate in 83 MHz of spectrum between 2.400GHz and 2.483GHz, while most traditional UHF wireless microphones in use today operate at lower UHF frequencies between 470MHz and 698MHz.

2.4 GHz Digital wireless microphone is highlighted because of its commonly used 2.4G type signal transmission which is not restricted by frequency band. Wireless mic at 2.4GHz can be used in the same frequency range in nearly every country in the world, though the rules for wireless mics vary from country to country. Mostly, the 2.4 GHz wireless microphone system gives users a free pass.

However, its downsides are obvious. One is the channel limitation. Such mics are not able to offer as many channels as expected because 2.4 GHz chips operate on less spectrum, and because 2.4 GHz is so crowded with Bluetooth and Wi-Fi devices. Hence, there would be dropouts or noises when 2.4 gigahertz wireless mic is used in the recording. By contrast, the UHF wireless microphone system designed for broadcast-quality recording is somehow professional. It is recommended for longer wavelength, a farther distance of signal transmission, fewer devices within the same frequency, and less interference. Of course, it also has disadvantages. It consumes much more energy because it needs greater power.

For users seeking a wireless mic system, the general rule is to choose a 2.4 wireless mic system if you only need a few channels, work relatively short distances, want operational simplicity, and make sure that your device will not be phased out depending on the future FCC changes. Mostly it is personal vlogging and entertainment.

For users needing lots of channels, ultra-low latency, and are capturing critical sound at a large stage, sports, or podcasting events, premium-marketed UHF systems remain the best choice for ultimate audio quality.

Tips about UHF and 2.4 GHz band

Here are some national policies we need to know against 2.4G and UHF bands.

National restriction on power: wireless microphone at 2.4 GHz is always restricted to use power within 10mW, while UHF wireless mic within 50mW. The transmission power has an impact on the range of sound pickup. Therefore, the 2.4G band has a shorter sound pickup distance than the UHF band.
National protection of the UHF frequency band: Some countries charge UHF bands. It’s suggested that each UHF wireless mic should first use the receiver to scan frequencies and find a frequency of stability once started. This would take about 1-2 minutes. A signal detector can be adopted to make sure that the signal is stable.