German rocker Udo Lindenberg recently started his Keine Panik! (Don’t Panic!) German tour. More than half a million people have attended his concerts in the past three years, and he’s packing stadiums and arenas again in 2016. Satis&fy, an international provider of event, media technology and scenic design solutions based in Karben, Germany (near Frankfurt), is responsible for the tour sound. The company’s 500+ people, its large fleet of vehicles and up-to-date gear make it one of Germany’s largest live event firms.
Enter the Xirium Pro
Recently, satis&fy and freelance sound engineer Arnd Wagner tested Neutrik’s new Xirium Pro wireless solution for sending stereo audio pairs from the FOH console to main or delay speakers. The test took place during two concerts at Hannover’s 14,000-seat TUI Arena.
Based on Neutrik’s DiWA (Digital Wireless Audio) technology, Xirium Pro offer sample-accurate operation in the license-free 5 GHz frequency range. That band offers ample bandwidth for DiWA to transmit uncompressed 24-bit/48 kHz audio on a par with hardwired cable over distances of greater than 500 meters from one transmitter to an unlimited number of receivers (point-to-multiple-point), even in high-RF areas.
The Xirium Pro system expands its flexibility by offering two different base units (TX and RX) that accommodate a various audio input and output modules. These include line-level analog, AES/EBU digital and Dante signals. Additionally, a repeater module for the RX base stations can extend range almost indefinitely. The modules can be combined, transparently and automatically converting amongst the various audio signal types, so for example, analog signals could be transmitted from the console and be output as analog, AES/EBU or Dante at the amp racks or delay tower.
Since 2008, engineer Arnd Wagner and satis&fy have accompanied Lindenberg on his tours, which have grown in scale over the years. The 2016 outing requiring 22 trailers — three with staging; two with P.A. Designed to accommodate the largest venues such as Stuttgart and Gelsenkirchen, the touring production makes use of an L-Acoustic system including as many as 56 K1 and 110 K2 speakers. In Hannover, the setup consisted of 40 K1 and 36 K2 speakers. Wirelessly connecting this via a bandwidth-limited UHF system was not an acceptable option. The Xirium Pro’s 24-bit/ 48 kHz cable-like response became the clear choice.
The Sports Venue Dilemma
A common issue with audio in sporting facilities is achieving maximum sound impact and quality to the upper tiers and, for indoor shows, the use of very tall speaker towers is inevitably limited by the venue’s roof. Meanwhile, stadium ceilings are designed to transfer the cheering and screams of the upper tiers down to the sports team and to fans at the lower levels.
Of course, such acoustic transfer is counterproductive for concerts. In order to achieve proper sound absorption in the upper tiers, the speakers have to “reach” into the upper tier area as far as possible, with maximum focus, in order to reduce slapback. That’s why satis&fy uses, in addition to three line arrays on each of both longitudinal sides, two additional line arrays aimed specifically at the upper tiers.
To control these amps, Ethernet cables are installed. Using IP tunneling integrated into Riedel RockNet, the control data is transferred to the amps. The IP tunneling offers only 10 Mbit transmission speed — sufficient for the control data. In big stadiums, satis&fy dedicates 40 amplifiers to the sound in the upper tiers, with all 40 amps supplied both control data and audio via a RockNet loop. However, in Hannover, the RockNet loop was used for the control data and as a redundant audio source. Xirium Pro was deployed as the primary audio source.
To complicate matters, Lindenberg flies through stadiums and halls with a spider system during his concerts. So, preferably, no cables should come down from the towers at any points. All cables must be dressed back and away from the towers — a very cumbersome process. In such cases, a wireless system like Xirium Pro from Neutrik proved ideal.
Ready, Setup, Go
Xirium Pro was not completely new for Wagner, as he already worked with the product’s predecessors. In collaboration with Neutrik support, Wagner planned the system configuration the day before the first concert in Hannover.
“On the day of the concert, the Xirium Pro setup was completed in just a few moments, showing its strength as a plug-and-play system,” Wagner notes. One Xirium Pro receiver was mounted to each of the two amp racks with a Manfrotto universal mounting clamp. The interchangeable modules offer 10 hours of battery life, but as onsite powering was available, the devices ran on AC power, simply by attaching standard powerCON cables. “After the setup was completed, the racks and delay towers were flown up to the stadium ceiling and the Xirium Pro receivers were no longer accessible. Therefore, the 40 x 35 degree (H x V) directional antennas were properly angled towards the Xirium Pro transmitting unit before the rig was flown.”
The transmitter and one repeater unit were placed directly at the FOH position. Because the receivers were located up so high, the sender and repeater units had to be mounted slightly angled on speaker stands to align to the two receivers at the ceiling. The repeater was used to create a redundant transmission line — what Neutrik calls “extended true diversity.” The repeater sends the signal, minimally time shifted, on an independent RF path. Such a diversity solution is a combination of time and room/space diversity, avoiding reflection-based phase cancellations and exceeding the effectiveness of even full diversity systems. Each receiver automatically selects the best signal, switching between the transmitter and repeater signals without interruption.
Xirium Pro is designed for static point-to-multiple-point wireless audio installations. Additionally, the Xirium Pro app (iOS or Android) simplifies setup and optimizing the wireless audio transmission. The app offers remote monitoring and control of all adjustable settings during a live event, such as the onboard delay times, frequency assignments, etc., as well as the monitoring of signal strength, battery power and more.
Tying into the System
“The complete sonic adjustment of the upper tier audio was made with the help of L-Acoustics’ LA Network Manager software,” Wagner adds, “utilizing both FIR filters and standard parametric filters. Further, LA Network Manager can adjust the so-called ‘zoom factor,’ providing additional DSP-based equalization.”
Wagner also uses LA Network Manager to set delays. Here, single channels can be grouped freely as desired. Xirium Pro also offers the ability to set a separate delay for each receiving unit.
The path to the nearfield speakers on stage is achieved over Dante via a Lake LM44 processor. Onstage Dante breakout boxes are supplied via a fiber optic system. The AES signal goes from the mixer via the fiber system to the stage and is played into the Lake processor which, in turn, sends a Dante signal to the breakout boxes on both sides of the stage. In this way, the primary and secondary audio signals are transmitted, along with a control V-LAN signal. Parallel copper lines are laid as well, providing a redundant signal path in case a Dante breakout box fails. If this occurred, the amps would automatically switch to the analog signal provided by the copper lines and apply a 3 ms delay, as defined in the amplifiers’ “fallback mode” settings.
Wagner sums up his experience with Neutrik’s Xirium Pro after the two Hannover concerts. “The transmission with Xirium Pro worked perfectly, and the sound was really comparable to cable. The wireless audio transmission remained robust even though there were two wireless cameras operating in the 5 GHz band. And during both shows, the app confirmed the excellent signal transmission quality at any given time.”
For more information, please visit www.xirium.net/en.
