Touring RF engineer Marc Depratto was looking for some solutions for helping him deal with wireless interference and frequency coordination issues. He eventually turned to two Kaltman Creations Invisible Waves X RF products — the RF Command Center and CPAntenna. Here are some of his experiences. —ed.
I have been a user of Kaltman Creations’ products since 2010 and was looking to buy an RF spectrum analyzer that would offer more functionalities than just scanning and be cost effective. After a bit of research, I found the Invisible Waves X RF Command Center. I had been working with basic scanners and was a bit disappointed by their lack of flexibility and the fact that, aside from going from left to right on the screen, they couldn’t offer real-time level monitoring of my carriers and many other features I required.
When I started working on the Michael Bublé’s most recent Crazy Love tour, our RF count was pretty low, but shortly after starting rehearsal and the first tour legs in the U.S., production desired to upgrade the monitoring system from four stereo IEM’s/12-mic system to a system with 14 stereo IEM’s and 12-mics. That is where analyzer capabilities of the Invisible Waves X RF spectrum came in handy.
Its ability to provide real-time monitoring of multiple frequencies with dropout alerts and a comprehensive interface simply suited my needs. It gave me the ability to have a fixed RF interface setup that I could update everyday without having to retype all of my marker names. I could just punch in the frequencies I needed to monitor and — there it was.
I was later contracted to take care of the RF/Comms for Cirque du Soleil’s
Michael Jackson: The Immortal World Tour. This challenge was different — as we have around 65 channels of RF, comprised of 18 stereo IEM’s, 25 mics, 12 RTS BTR-80N intercom packs and four TX frequencies for these BTR-80N’s, along with spare frequencies.
Having stepped in after the beginning of the tour, I was on an already-built set. I thought I could bring my tricks of the trade to improve on what I could. The setup called for very solid radio links, especially for the comms, in that all calls for acrobatic flights, show calling and set piece movements require the coordination of more than 20 people on deck. If an emergency was to occur, this is the vital link. The shark fin antennas provided good sounding links, but with quite a bit of hissing, and occasionally some multipath dropouts, depending on the venue.
Enter the CPAntenna
When I saw that Mark Kaltman and his team had come up with a new CPAntenna — using circular polarization technology — I contacted them and got a few units to take on the road.
Typical rod and paddle antennas used for wireless mics are polarized along either a horizontal or vertical plane, so when an RF transmitter (handheld or bodypack) changes its orientation in reference to the receiving antenna, the phase relationship can change. This can result in greater drop outs, lowered RF signal-to-noise performance and increased interference.
The circular polarization approach used in the IWxCPA antenna addresses these issues, yielding transmitter/receiver operation that remains in phase. With that, I decided to use one of them as the RX antenna on my BTR system. The result was very impressive.
Although at first, the scanner reading was showing a bit lower strength on the carriers, the consistency of the reception coverage and the absence of residual noise were stunning. Additionally, the coverage distance went from backstage almost 100 feet to the end of our B stage.
Having met success with that, I decided to try them on the RX for our mics, and the result was consistently as good. As I mentioned, many of the production numbers take place on the B stage, and, as before, the coverage was very consistent.
Cirque du Soleil’s Michael Jackson: The Immortal world tour, which launched in Oct. 2011, logged 426 shows around the world before returning to North America this year. The production continues this year with the total performance count approaching the 500 mark.
For more information, visit Kaltman Creations at www.kaltmancreationsllc.com.
