The main hang
Weighing all these factors, Tallman found the ideal box around which to build his design: the very compact and lightweight Electro-Voice XLD281 dual 8-inch line array element. Designed for biamp or triamp operation, the XLD281 is a full-bandwidth 3-way box in EV’s XLVC series of installation-focused arrays. With EV’s Coverage Control Technology (CCT), the box maintains 120-degree horizontal coverage down to 250 Hz.
“The XLDs fit all of our design criteria,” Tallman says. “I’ve used them in live situations, and I’ve used them in multiple installs. They handle the right amount of horsepower and they are able to cover the room evenly from a single point hang.” Both Tallman and David Brown, CFO and lead engineer for Quantum, had worked extensively with the XLD281 and both had zero doubt it would do exactly what the theater wanted – both sonically and aesthetically.
“The XLDs come in both 90- and 120-degree horizontal patterns,” Brown adds. “We looked at using 120s more toward the bottom and 90s up top. I did a full EASE analysis on the room, looking for any anomalies of energy and phase from things like multiple reflective points or corners coming back and hitting certain seating areas. When I ran the numbers, we got a smoother overall response with just the 120s than with a mixture.”
“The 90s would definitely have given us a little more oomph in the back, but it just didn’t look like we needed it. So we ended up going with 120s all the way, and it worked well. Everything falls off right where I wanted it to. When a person in the last row of the balcony stands up, they’re still just within the pattern… unless they’re over seven feet tall!”
“We designed it to be something that a touring artist would sign off on,” Tallman says. “The number of boxes was influenced by what it took to get control down to the breaking frequency that I thought we would need after having been in the room and knowing where the problems were. But we also had to avoid interfering visually with the proscenium arch. The bottom of the array should never intersect the arch of the proscenium by more than a foot from the upper rows or any other viewpoint in the theater.”
The final design is a ten-box hang with a hard break in the middle to avoid bouncing sound off of the balcony lip. “We wouldn’t normally have done a hard break,” Brown says, “but EV’s new FIR filter presets for the XLDs make the array behave so well that we can decouple those two sections more than normal, and the break takes the energy off of the lip like we want. The pattern picks back up on the other side and still sounds great. They’ve done such a good job with these final presets – they are fantastic.”
Tallman chose four Electro-Voice Xi-1082 2-way full-range loudspeakers for front fills. Another six Xi-1082s are used for under-balcony fill. “We like the size of the box and its value,” Tallman says. “It’s very affordable for its output and overall sound quality. And it blends well with the main hang because EV keeps the overall tonality very similar from box to box. The consistency of EV’s speaker voicing makes it easy to get a smooth transition between coverage zones.”
The system is equipped with two different models of Electro-Voice subwoofers. Two EVF1181S single 18-inch front-loaded subwoofers live in what Tallman refers to as a “bunker” built for the old system’s DeltaMax subs. “We had to find a sub that fit in the bunkers that were already there,” he explains, “because we weren’t going to be able to put subs under the stage or install them near the stage.”
“If the show is just talking heads, or there’s not a whole lot of low-end material, then they can run with just those loft-mounted subs,” Tallman continues. “When it gets a little more pumping and it needs more low-end punch, then they have four dual-18s that they roll out onto the stage right next to the proscenium. Those are EV’s QRX 218S compact dual 18-inch subwoofers. I chose that model because it’s a high-output, low-profile, sub that fit within the budget. I’ve used them over and over again. Four of them provide enough low-end to keep up with the mains and the overall SPL requirements for the low frequencies.
Also used on a situational basis are the theater’s eight TX1122 12-inch two-way full-range loudspeakers, which serve primarily as floor monitors. “They pull them out when they have concerts,” Tallman says. “We chose this model for its output and its quality; it was the right price-performance ratio. But footprint was also a concern. The enclosures are compact. It’s a radical design that really takes up less space on stage without sacrificing performance.”
Power and control
Designing the entire system around the XLD281 was made easy with the use of Electro-Voice amps and DSP. “My design philosophy follows that if DSP, loudspeakers, and amps can all come from the same manufacturer then they should,” Tallman explains. “I’ve done installs with amps from other manufacturers behind EV speakers and those installs sounded very good. But knowing that EV amps are over-engineered and built really well, I knew they would enhance the experience we were looking for. From the output power to the very low failure rate and power consumption, the performance-to-cost ratio makes them more than affordable. EV amps are competitive with anyone on the planet in terms of power and value.”
Fifteen CPS amps are used in all: five CPS2.9s, nine CPS2.12s, and one CPS8.5. “The CPS2.12s are used for the LF drivers in the main array and the subs,” Kang adds. “The CPS2.9s are used for the HF on the XLDs and also for the Xi-1082s. And the CPS8.5 is used for the monitors.”
Each amp is equipped with an RCM-810 card that functions as an IRIS-Net remote control module. “The RCM-810 allows you to monitor your system and see what’s going on without having to get on a ladder or pull out test equipment,” Brown says. “You can see in real time if your drivers are in good shape, and check things like the impedance of the rig. Also, if you use the RCM-810 card on a digital amplifier like the CPS8.5, 4.5, or 4.10, it allows you to control the output stage based on your calculated load. You can adjust your output impedance and stabilize it, so that it matches the overall impedance of the load that you’re actually driving.”
While the DSP on the RCM-810 cards is used for supervision and load matching, the audio processing is handled by a NetMax N8000-1500 digital matrix controller. “There is no better sounding audio processor,” Brown says, “and it does everything. It’s just a powerhouse in terms of DSP – crossovers, compressors, and all of your limiters are in there.”
Kang agrees with Brown’s assessment. “The capability to process FIR filters in real time makes the N8000 the ultimate configurable processor,” he says. “It is very versatile in how it programs and can do quite literally almost anything you ask it to do. It’s also great sounding and roadworthy too.”
Given the NetMax’s capabilities, it was the obvious choice for running the theater’s Electro-Voice amps and loudspeakers. “It just makes sense to use the same manufacturer’s DSP box,” Brown says. “EV has spent a lot of time coming up with those loudspeaker presets and FIR filters, making sure that everything in the system is gain-structured properly and all of the frequency responses line up. So when I load in the speaker parameters, they’re going to be correct. If we’d chosen a different brand of processor, I would have had to do transfer functions for a 10-box rig, which is a lot of work.”
Brown also points out that NetMax is “not just a loudspeaker processor. It’s also a 32 by 32 digital matrixing device that you can use to do all of your routing. So it’s a fantastic front-of-house box, but it can also take care of the rest of the venue with things like matrixing background music and routing your paging. It also can run CobraNet modules and Dante. So you get your choice of networking and how you talk to other devices.”