Classroom audio can improve the attention of students. There are three main types of wireless microphone frequencies, you should look into: 2.4 GHz, infrared, and UHF (ultra high frequency). All three have both positive and negative aspects. If you are looking to purchase, we suggest you do your research.
About 2.4 GHz
First, let’s talk about 2.4 GHz. 2.4 GHz band wireless audio gear includes Line 6 microphones, the Sennheiser EW-D1, the AKG DMS-Tetrad, the Shure GLX-D, Tempest 2.4 GHz intercoms, and a few others. Recently, 2.4 GHz microphones have grown in popularity because they require very little frequency coordination, and are legal and unlicensed in every international region.
2.4 GHz microphones are simple and easy to operate. They are also great at self-coordinating and communicating with other microphones. One or two channel 2.4 GHz microphone systems usually perform well. However, 2.4 GHz is a crowded band. Most technology does not require real-time uninterrupted operation, like wireless microphones do. Because of this, WiFi can interfere with wireless microphone systems.
About WiFi Interference
Interference may become problematic on multi-channel systems, or where WiFi utilization is intense. Since WiFi is such a prominent feature on smartphones, the 2.4 GHz band does not perform at it’s best anywhere there are lots of people and WAPs that offer up connectivity. Smartphones do not only use WiFi for internet access. Phones make calls through dedicated “voice over WiFi” apps or through what is known as WiFi offloading.
Controlling interference from the WiFi is difficult for two reasons. First, WiFi sends out rapid bursts of RF (radio frequency) that constantly hops frequencies, unlike analog transmitters which stay on a single frequency. You cannot coordinate around a WiFi device because it does not stay put. Second, WiFi is used by everyone yet controlled by few. You cannot ask IT departments and cell phone owners to stop transmitting. Even if you did, short of completely powering them down, smartphones and other consumer WiFi radios operate automatically and out of direct control.
Next, let’s talk about infrared microphone systems. Infrared microphone systems use an infrared light to transmit the signal between the microphone and the receiver. This microphone system is best used for short and medium range communications. Infrared will likely cost you the least amount of money and can produce fair sound quality, however, there are limitations.
If you operate under Windows, you will probably not want to use infrared because this system is notoriously bad with Windows. Unlike RF wireless links, infrared wireless cannot pass through walls. Infrared communications are not possible between different rooms. With this technology, a direct line between the transmitter and the receiver is critical because without a direct line, the sound will drop out.
About Ultra High Frequency (UHF)
Lastly, let’s talk about UHF wireless microphone systems. UHF mic systems will give you clear reception with less dropout zones.While the operating range between UHF and 2.4 GHz is not all that different, the UHF band has longer range and transmits better through solid objects. You will also be able to use more wireless channels with UHF.
Even though UHF mic systems can do more, they also cost more. Because 2.4 GHz operates on a smaller wavelengths, you will get more features in comparison to a UHF at a similar price point. Bands can become more crowded with UHF in comparison to the other two systems, which brings back up the point of WiFi interference. As we explained, interference is pretty much out of your control.
As you can see, there are pros and cons to all three of the wireless microphone systems previewed above. We suggest that you do your homework on all of the options before making a commitment.