A lot of what we do in sound reinforcement involves attempting to do what amounts to a seemingly impossible task. This may come in the form of mixing in some acoustically horrible environment with glass walls and marble floors. Another vexing issue comes when you need a long cable run of up to a half mile across rough terrain, crowds, a body of water, a stadium, an alligator pit or other obstacles — or simply do a gig in a museum, theme park, convention center or historic building/site, where extended cable runs are either impractical or simply prohibited.
Enter XIRIUM PRO
While there are few options for presenting intelligible audio in what is essentially an echo chamber, there is now a solution for dealing with extended and/or difficult cable runs. This comes in the form of the Neutrik XIRIUM PRO Wireless digital audio system. Unveiled at Winter NAMM 2016, XIRIUM PRO is a cable replacement system, providing two channels of audio connectivity to/from devices (such as console output to main or delay speakers) without long or complicated cable runs. The system wirelessly delivers full-bandwidth (24-bit, 48k Hz), compression / compansion-free audio at distances of more than half a mile with a mere 3.6 milliseconds of latency.
Systems can be as simple as a single two-channel transmitter (TX) and receiver (RX) base station pair, but easily expanded into more complex configurations. Six interchangeable input and output modules include analog XLR, AES digital pair (on a single XLR) and Dante, also as a two-channel pair. One of the coolest things about XIRIUM PRO is that the system can perform format conversion, so if you want to send AES and receive Dante at the other end, a simple module swap and you are ready to go. The same would apply to sending analog and receiving AES or vice versa.
The XIRIUM PRO platform allows as many as five transmission units for up to 10 simultaneous discrete audio channels. On the receiving side, XIRIUM PRO supports an unlimited number of receivers, as long the receiver is within line of sight of the transmitter. This is ideal in applications such as delay towers, as individual distance compensation delays can be set within each RX receive unit.
Another unique and powerful aspect of XIRIUM PRO is a repeater module, which connects to an RX station in place of its output module. The repeater receives the signal from the transmitter and sends the identical signal again. So the repeater can be used as a range extender, a means or getting around barriers (such as trees, buildings or walls) or simply as a means of achieving redundancy by setting up an extended true diversity rig.
Inside the Hardware
The TX and RX base stations are massively overbuilt. Each is a sizable 5.5 by 10 inches (less antennas), weighs five pounds and is housed in a near-indestructible (and water-resistant) extruded aluminum body. The review system was supplied in a tough, molded, foam-lined road case. Two detachable antennas (a small, reverse SMA 2.4 GHz one for communicating control/status monitoring to an iPad or Android tablet) and a large, N-type 5 GHz antenna (for audio transmit/receive) are provided with each base station. The system features variable RF output power, with up to 3.2 watts EIRP, when used with a high-gain 9 dBi antenna.
The rear of each station has a 5/8-inch mounting stud and a bracket for a safety cable. Both attach securely to the unit. I however, would prefer that the cable attachment would accommodate an 8mm carabiner. [Note: This has already been incorporated into current versions.—Ed.] The 5/8-inch stud is a standard in film/video lighting and we happen to have a large stock of Lowel and Mole-Richardson stands and clamps in our shop. However each XIRIUM PRO kit comes with sturdy Manfrotto swivel clamps that attach to flat surfaces or pipes up to 2-inches in diameter, so it’s ready for anything.
The modules include internal lithium-ion rechargeable batteries for nine to 10 hours of operation. Yet in most situations — such as connected to a console or delay stack, where 110 VAC is readily available — the units will be powered by the powerCON TRUE1 locking AC cord. Other than knowing that onboard battery backup is always there in the case of a short-term power loss, I really came to appreciate the battery powering, which made for simpler setups on site, where I could set/assign parameters or frequencies before AC lines were run.
The RF Technology
The system is based around Neutrik’s proprietary DiWA (Digital Wireless Audio) technology, offering sample-accurate operation in the license-free 5 GHz band. Also incorporated into the system is FEC (Forward Error Correction) combined with a repair algorithm (allowing package losses without dropouts) and an XROC (Extreme Ruggedized One Channel) mode for extremely congested RF areas.
Designed for no-fail operation in interference-prone, unworkable RF environments, in XROC mode, only one channel of the device can be used. The modulation changes from QAM 16 to BPSK. The result is a reduced bit rate from 24 Mbit/s to 6 Mbit/s, with the effect of an extreme ruggedized transmission. In such extreme cases, the show goes on, at the expense of mono, rather than stereo operation. I did not encounter any situations where XROC was required, but it’s nice to know it is there — just in case.
The 5 GHz band offers ample bandwidth for optimal audio transmission and is ideal for a one-point-to-many-points cable replacement. Also, the longer wavelengths of UHF band are better suited to wireless mics, where performers may constantly be in motion and shorter 5 GHz waves would more prone to be absorbed by performers or actors, or reflected by walls or set pieces. However, in an unchanging line-of-sight application, such as console to main P.A. or delay stack, 5 GHz works well.
One caveat about XIRIUM PRO is that the system not only requires line of sight setups, but that the transmitter and receiver (or repeater) need to be aligned within a Fresnel zone on the same plane for optimal operation. XIRIUM PRO’s 5 GHz RF signal travels in an ellipsoidal path, so if your transmitter is on an eight-foot stand (to avoid anything getting in the way of the signal) and the receiver is mounted 16 feet up on a delay tower, the two units will have to be angled upward and downward slightly to operate in both line of sight and the same plane. Not really a big deal, but something to keep in mind during setups, and that swivel clamp simplifies the process.
System setup is straightforward, thanks to a simple system of linking (syncing) two units that requires little more than a single button push on each. Getting deeper requires the free iPad or Android XIRIUM PRO app, for access to frequency/channel and setup parameters, power levels, delay times, and monitoring of battery charge, signal strength and XROC mode. The app also speeds alignment of the Fresnel angles between two units for optimizing RF performance. Alternatively, a network mode is also offered for communicating via an existing network.
The Bottom Line
I was impressed with the XIRIUM PRO. The audio performance was virtually indistinguishable from a cable, even at a distance of nearly a half-mile. The build quality was impeccable, setups were simple (with an easy-to-use app) and the system’s modular design provides both versatility for day-to-day operations and scalability for future expansion. It allowed me to achieve impossible signal runs under tough conditions. The system is not cheap, but going first-class was never an inexpensive proposition. And not having to deal with cable routing, dressing and cable taping? Priceless. I could get used to that.
At a Glance
Versatile, Solid Cable Replacement System
Cable runs of up to a half-mile (or more) now become easy to implement, even under seemingly impossible conditions, with a flexible system for portable or fixed installation use and scalable for future needs.
Neutrik XIRIUM PRO
PROS:
- Hard-wired audio quality — even over long distances
- Rock-solid RF performance
- Fast setups with iPad monitoring/tweaking app
- Multi-format (analog, AES, Dante) support
CONS:
- Somewhat pricey
- Max sample rate of 48k Hz
STATS:
- Sample Rates: 48k Hz
- Bit Depth: 24-bit
- RF Band: 5 GHz (audio); 2.4 MHz (control)
- Dimensions: Each unit is 10 x 5.5 inches
- Weight: Approximately 5 pounds
Price (MSRP):
Basic Kit ($6,420) includes TX transmitter with analog module; (2) RX receivers with analog receive and repeater modules; antennas, cabling, mounting clamps and molded flightcase. Starter Kit ($3,298) has analog transmitter and receiver, plus antennas, cabling and clamps. Individual components and options also offered separately.
Manufacturer: Neutrik
More Info: www.xirium.net
JJ Jenkins is a live sound and studio engineer based in the San Francisco area.
