Iconic rock star Peter Gabriel is currently performing his 1986 album, "So", on the road. With those live performances comes the the constant threat of disruption caused by frequency interruption. How are those concerns resolved?
Those responsibilities are in the capable hands of tour engineer Jimmy Nicholson, and Broadcast Engineering caught up with him to find out what steps he takes to keep his signal flow in order and keep Gabriel sounding great.
BE: You use the Kallman Creations Invisible Waves X RF Command Center. What advantages does this package have over its competitors?
JN: To be honest, it's a fairly unique product. I find most hand held scanners, whilst having the advantage of letting you walk around the venue with them, are unable to display the wide range of information in such a user-friendly way as the RF Command Center, likewise with hardware-based traditional spectrum analyzers. The click-to-listen,audible alarm for dropped frequencies or rogue new ones, the ease of placing markers on your spectrum graph and excellent visual feedback for monitoring your key frequencies are features pretty much only available with the RF Command Center.
BE: You executed intermodulation calculations using the Professional Wireless IAS software. Again, what advantages does this product have over the competition?
JN: Again, until recently, there hasn't really been any competition. Software provided by manufacturers has been heavily focused on their own products, and has required some extra legwork when dealing with a mixed selection of products from different manufacturers. The IAS software has been by far the quickest way to get these calculations done in that situation.
However, I'm now looking forward to trying out the new RF-intermodPRO software from Kaltmann Creations. It's designed to do everything that the IAS software does, and also integrate into the RF Command Center software, allowing you to easily take into account your scan of the local RF conditions when performing intermod calculations.
BE: Is there any “real world” advantage to having the ability scan frequencies as high as 3.5GHz?
JN: On the Peter Gabriel "Back To Front" Tour, we have five or six wifi networks running on stage/FOH for audio, video, lighting and backline control. In addition, there are 3 wireless MIDI systems in use on stage that transmit using the '2.4GHz' band that all consumer wifi devices share. Obviously, these wireless systems are key to the smooth running of the show, particularly the wireless MIDI transmitters. Being able to scan in this region can be key to troubleshooting this critical aspect of the production.
BE: You mention that many venues in the UK have multiple acts performing in the same building, often without regard for the regulations that govern audio frequencies. Once you dial in your frequencies, prior to a show, how concerned are you that bandwidth will be compromised during a show?
JN: Concerned enough to have spare microphone and IEM systems on alternative frequencies available at a moments notice! I consider this to be prudent anyway, regardless of the local RF conditions. Possibly the simplest way to minimize this issue is to load-in early, set your frequencies and then leave them transmitting all day. I usually leave all IEM systems on, but microphones off. This way, if someone in a nearby venue turns on their systems and discovers interference (from your transmitters), they'll most likely retune their systems to avoid yours. There are generally less mics than IEM systems on most tours, so retuning a couple of mic frequencies before a show is not a big deal, fetching IEM packs back from dressing rooms for a last minute retune is significantly more disruptive.
Of course, if you have an RF Command Center at your disposal, you can leave it scanning the relevant area of the spectrum all day, take snapshots of the spectrum graph as the day progresses, and have the audible alarm warn you of newly-appearing rogue frequencies if you wish!
There is obviously no substitute for careful planning, being prepared and communicating with other RF users in the local area. The Invisible Waves tools, and indeed tools from any other manufacturer are exactly that — tools. They will not setup your RF systems for you (and they certainly won't help you get them out of the truck!), but used in combination with proper planning and preparation, they can make things a lot easier and quicker when the pressure is on!
Overall, Nicholson has been a working audio engineer for over a decade. Check out his website for details.