Wireless Microphones Wireless mic systems give you the freedom of movement, and the ability to be away from the stage that obviously is not achievable using a traditional wired microphone.
The average wireless system will come with a receiver unit of single or twin channel, and be packaged with standard dynamic microphones in either normal handheld or a headset design. The main differences between wireless systems are their operating frequencies and the design features of the receiver unit, which vary with the price and quality level of the system. All digital systems are available, but are generally a much higher cost, so the standard setups still use an analogue signal, which is then digitally locked to a specific frequency. Many of the systems also offer a choice of these locked frequency channels to select from, either for avoidance of interference, or for multiple simultaneous mic use
These standard systems are offered in either traditional VHF (Very High Frequency) bands, or the newer UHF (Ultra High Frequency) range, which offers better transmission length and less noise from interference caused from other signals in that band such as radio and television, computers and digital devices. Technically, the systems will be no different, and under general conditions will perform no differently either, with the UHF equipment only really coming into its own at longer distances, or when used in situations where a lot of other equipment is present. It's more an evolution to avoid future issues rather than a replacement, and is also to cater for certain world markets where the VHF bands have been taken away from public access.
An important feature of modern wireless systems is a twin aerial ‘diversity’ receiver, which uses its two separate channels and aerials to continuously select from the strongest incoming signal and avoid the dropouts of older systems, which are due to the transmission being deflected off objects and blocked by nearby electrical equipment, an effect which is known as multipath. It also increases available range, and allows for a more trouble free operation. Microphones are battery powered, and will usually give a good 8 to 10 hours usage from standard batteries, most of which require two AA types. The receivers are usually low voltage dc with a mains adapter, and will feature balanced mic level and unbalanced line level outputs for versatility in connection.