VHF vs. UHF: What Wireless FM System Is Ideal for You?
If you’re in the market for a wireless microphone (or assisted hearing system), chances are you’ve checked out both VHF and UHF models.
And you’ve probably noticed some key differences, especially when it comes to price.
What’s the difference between VHF and UHF wireless systems, and which is the ideal choice for you?
What’s the Difference Between the VHF & UHF Bands?
All FM wireless microphones, transmitter and receiver systems operate using radio waves, which (in modern times at least) are measured in cycles per second. These waves are measured in megahertz (mHz, or millions of hertz).
VHF (Very High Frequency) transmissions occupy the frequency bands from 30 to 225 mHz. Some of this bandwidth was once taken up by the pre-digital TV channels 2-13, but now almost all of it is used by low-power wireless devices, FM radio and other communications, emergency providers and some digital TV stations.
UHF (Ultra High Frequency) transmissions start where VHF ends, ranging from 226 mHz all the way up to 3 gigahertz (gHz), where microwaves take over.
Should You Choose a VHF or UHF device?
The big difference for wireless devices using these bands is power: UHF requires much more power to generate higher-energy waves.
The amount of power used by UHF devices means that it can operate at a higher frequency. However, this also has drawbacks: more power means UHF devices have a shorter battery life.
UHF devices are also better suited to areas with a high potential for interference. Because VHF bands are not frequency agile, they only work on one channel. Some UHF systems are also single channel, but many are available as multi-frequency units, ranging from 16 to 100 available channels. The ability to change frequencies (thereby avoiding interference) is the main reason why UHF systems are typically more expensive.
Additionally, VHF bands escaped 2010 FCC regulations re-allocating radio frequencies, which means it’s still possible to use an older VHF microphone system, while UHF systems of a similar vintage may use a prohibited frequency (specifically, the 700 mHz band).
It’s important that you choose the right product, especially if you’re using wireless mics. UHF wireless microphone systems tend to be the choice for live music venues and other operators for whom sound quality and interference-free performance is key.
To sum it up: If you’re on a budget, operating in a small space, and don’t need to provide audiophile sound, a VHF system is your best choice.
If music-quality sound is important to you — or if you’re operating in a large venue, or a location with a high chance or interference — consider a higher quality, multi-channel UHF wireless system.
A Word on Assistive Listening Systems
What about FM assistive listening devices, like tour guide and other personal transmitter/receiver systems? Most of these operate in the VHF frequency ranges of 72-76 mHz and 216-217 mHz.
These frequencies were allocated by the FCC to minimize interference with other devices, although of these two ranges, 216-217 offers better reception.
Recently, devices like the Williams Sound DigiWave system have edged their way into the higher reaches of the UHF band. Users can likely expect to see more UHF listening systems offering improved reception and sound quality in the not-too-distant future.
Do you have experiences with UHF or VHF wireless microphone or hearing systems? Tell us about them in the comments!