The ins and outs of wireless microphone systems have caused many amateur (and more than a few professional) sound engineers to scratch their heads in confusion.
Reception, interference, operating frequencies — not to mention price — can make choosing a wireless mic a daunting business.
Wireless microphones operating in the UHF frequency band are often cited as the optimum choice for pro sound, given their stronger power output and lower susceptibility to ‘dropouts’.
But they’re not the only choice.
VHF wireless microphones can be an inexpensive option for churches, conference rooms and other venues where sound quality isn’t a prime consideration.
What’s the difference between UHF & VHF wireless microphone systems — and which one is right for you?
UHF & VHF Wireless Spectrum: What’s the Difference?
“UHF” (Ultra High Frequency) and “VHF” (Very High Frequency) have different names because they operate in different bands of the FM spectrum.
UHF wireless systems operate in the 470 mHz to 698 mHz bands. The so-called 700 mHz band — between 698 and 806 mHz — is off-limits due to FCC regulations issued in 2010.
Although some digital wireless systems use frequencies between 902 and 928 mHz, the crowding of this range by household wireless devices make it a poor choice for analog wireless mics.
The VHF band spans 150 – 216 mHz, roughly the same frequencies old timers may remember as containing the broadcast TV channels from 7 to 13.
VHF vs. UHF Wireless Mic Systems
There are advantages and disadvantages to wireless systems in both the UHF and VHF bands.
UHF wireless mic systems generally boast clearer reception with fewer ‘dropout zones’ (areas where your mic won’t work) than VHF wireless mic systems.
On the other hand, UHF systems draw more power — meaning your batteries will run out faster than in a VHF system. And if you have an old system that operates in the 700 mHz band, using your UHF wireless system is now illegal and may make you liable for stiff penalties.
The main advantage of VHF wireless systems is that they’re far more inexpensive to build — and therefore carry a much lower price tag than UHF systems.
As mentioned above, VHF wireless mic systems also have the advantage of a longer battery life.
With their lower power, however, VHF wireless mic systems are more open to interference.
On top of that, they have larger dropout zones, meaning you’ll need to move the transmitter long distances to adjust to interference-free operation.
What Wireless Mic System Is Best For You?
One final consideration — especially if you’re working with an existing sound system — is compatibility.
A UHF receiver won’t recognize transmitters operating in the VHF bandwidth, and vice versa. If your PA system has a built-in wireless receiver, be sure and check which frequency range it uses BEFORE you reach for your wallet.
After you’ve examined your existing system, consider whether or not you’ll be using your mics for music. In general, VHF mics are recommended for speech (and other less fidelity-critical applications).
Have any questions about choosing a VHF or UHF wireless microphone? Give us a call at 407-757-3326 or send our trained staff an email!