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With all the recent discussion about how difficult it may become for our industry to use wireless audio devices, it’s comforting to know that at least one manufacturer has been hard at work on something that makes using wireless audio easier. Professional Wireless Systems (a Masque Sound Company) has developed a product called Intermodulation Analysis Software (IAS). The purpose of IAS is to facilitate coordination of wireless audio frequencies in any locale, minimizing the chance for interference with local television and radio stations.

When You Arrive
We’ve all faced the problem of trying to use our wireless gear in different parts of the country: When you arrive at a certain area, you have to do a bunch of detective work (or trial and error) to find out how to set the frequencies on your wireless units to avoid interference. IAS automates a large part of this process. Upon arrival at a location where you intend to use wireless audio, you load the local TV channels into IAS. If you know what these channels are, simply enter them into a list. If you are unfamiliar with the area, the software provides a frequency “wizard” that helps you identify local broadcasters.

IAS includes a database of FCC-registered television stations that is periodically updated for accuracy. In addition to the name and physical loca-tion of the station, the database provides the call letters of the station, the operational status and the broadcast strength of the signal. Analog (NTSC) and digital (ATSC) TV stations are included in the database as are PAL and DVB. If you enter the latitude and longitude of your locale, IAS also can search for these local stations. For those who are geographically challenged, the program will accept any of 40,000 zip codes and then calculate latitude and longitude for that zip code.

Once the active stations in the area have been identified, they are imported into a list and shown on a color-coded display at the bottom of the screen. This list will be compared and tested against the frequencies of your wireless system(s). IAS also maintains a database of wireless products organized by manufacturer, model and frequency agility of the unit, so if you select (for example) a Shure UR system, the software knows the fre-quencies on which the UR can operate. Running the test compares the possible operating frequencies of the UR system to the frequencies of the active TV stations in the area. Then, IAS displays the frequencies of the UR system that are least likely to conflict with the active broadcasts in the area.

Here is where the similarity to previous wireless spectrum analysis software ends: Intermodulation Analysis Software can import the data regarding the Shure wireless system into the “active” window, appending the list of active frequencies for the locale. When you add the next wireless system — say a Sennheiser personal monitor system — the test process is repeated, but this time the Sennheiser system’s possible frequencies are com-pared to the entire active list, including TV stations and the Shure wireless system(s). As wireless activity for an event gets more complicated, the software keeps track of the frequencies you already have earmarked for use with other wireless audio systems. Intermodulation Analysis Software works with systems from Audio-Technica, Electro-Voice, Lectrosonics, Sennheiser, Shure, Sony, Telex and others. Of course, once IAS has indi-cated the optimum channel set up for your wireless devices, it is up to you to actually set the wireless transmitters and receivers to the appropriate channels.

This is Cool Because…

So what’s the big deal? Well, Intermodulation Analysis Software really isn’t going to shine in a situation where you are running one or two chan-nels of wireless gear with a touring band. You have to envision Intermodulation Analysis Software in use on a large-scale event. Take the Super Bowl, for example, an event at which there may be a thousand wireless audio channels in use simultaneously. There are three problems with coor-dinating wireless frequencies for such a huge event. The first is identifying local broadcasters and finding a sufficient number of open channels in the area. The second is assigning these open frequencies to their respective equipment and users while making sure they don’t step on each other. Third, multiple frequencies operating in the same region can interact to form new harmonic frequencies that interfere with other channels (this is called Intermodulation). In the past, this job was a full-time day gig where a human being had to search FCC data for active channels in the loca-tion, log these frequencies into some sort of database, search frequency charts for various models of wireless audio gear and compare them to the local broadcasts, making sure that no one frequency would be assigned to multiple users!

It appears that IAS has taken a time-consuming, high-brain-damage process and turned it into an easily managed task. Intermodulation Analysis Software runs under Microsoft Windows 2000 and XP. For more information, check out the link at www.professionalwireless.com/ias/index.aspx     

Steve “Woody” La Cerra is out on a never-ending tour mixing front-of-house for Blue Öyster Cult. He can be reached via e-mail at Woody@fohonline.com.