Taking The Mystery Out Of Wireless Microphones

by Audio Technica, U.S.

Wireless microphone systems are probably among the greatest audio conveniences ever introduced! To have complete mic-mobility without the cumbersome cable is indeed a whole new experience to those used to traditional wired microphones. But while the successful purchase of a wired mic system is easily accomplished with a "listen to it, like it and buy it" approach, not so with wireless. Let’s address some of the more elusive disciplines required to ensure a successful wireless purchase and experience.

Diversity or Non-Diversity

One of the great enemies to the wireless user is a phenomenon called "multipath interference." It occurs when the transmitted signal of the wireless mic reflects off of walls, beams, metal objects, etc., presenting the wireless receiver (the box with the antenna) with delayed elements of the transmission, and thereby creating distorted by-products of the original audio signal. It’s not unlike the "fading’ or "modulating" that we sometimes hear on the AM radio band when we drive our car. Diversity wireless systems, like the Audio Technica 1100 Series, contain two receivers in one housing. A microprocessor decides which receiver has the more useable signal and switches the audio output to that receiver. The result is a cleaner, more consistent audio.

How do you know if you need a diversity wireless system?

Well, if the receiver can be placed to remain within, say 15 or 20 feet of the transmitter, with no obstacles between them, you probably have a pretty good shot at success with a non-diversity system, like the Audio Technica 300 Series. Likewise, if your system will be used outside wi5h no obvious obstacles. In most cases, however, if you are using the wireless inside, you will almost always benefit from a diversity wireless system.

Frequency Selection

Although very few people actually pay attention to the frequency of their wireless, it is perhaps the most important consideration after deciding which wireless system to purchase. The FCC has reserved frequencies in for wireless audio in the same bandwidth as VHF televisions. If you wireless frequency lands too close to a local television station, you audience may hear reruns. Of Mer. Ed in between you sentences. Consequently, it is important to work with you Lentine’s Sales Associate who will know ahead of time what frequencies are safe to use in your area, avoiding any problems in the future.

Proper Usage

Avoiding interference through purchasing the proper wireless for the environment in which you will be using it, and through thoughtful frequency selection, will send you well on your way to a successful wireless experience. But proper usage is equally important. Here are some good guidelines to get the most out of your wireless.

Position the antennas properly. They should be mounted at a 90-degree angle to one another. On the 300 Series, make sure one antenna is horizontal and one is vertical.

Extend fully the belt pack antenna. On lavalier system, clip the belt pack on you belt at the small of your back so the cable extends from you front, around you side to your back. This will minimize blockage of RF from you body. Keep the mic body pointed away from your body. With a hand held wireless system, pointing the base of the mic at about a 50-45 degree angle away from you chest will minimize blockage of RF from you body.

Use the same brand of battery. Unfortunately, the 9-volt battery is the standard size. As a consequence, the contacts can vary in size up to 1/16th of an inch. Using the same brand of battery ensures a secure battery contact every time.

Do not use rechargeable 9-volt batteries. Most only charge to 7.2 volts. Since wireless transmission will start to degrade substantially at around 7 volts, this would greatly reduce wireless time.