87 loudspeakers, 72 amp channels, and tuning -- all in a very tight timeframe...
July 11, 2014, by Marcus Ross
At 9:30 pm on a Tuesday in December, I had five teams totaling more than 30 people poised to descend on the Blue Man Theater at the Monte Carlo in Las Vegas to implement a new house system.
With less than 48 hours, including meal breaks, turnarounds and hopefully a nap or two, everything had to be ready for a show by Thursday at 7 pm. The organized chaos worked even better than imagined and the sonic improvement is nothing less than stunning.
The choice to make the system upgrade at the 1,500-seat, three-level venue began only a few months earlier when the artistic and production team from Blue Man Group were at the Sydney Lyric Opera house in Australia, building a new production. As resident audio supervisor for Blue Man, I was tasked to design an entirely new system from the ground up for the production down under.
After a lengthy evaluation process I chose L-Acoustics KARA line source arrays for their sonic quality and compact size. From the beginning of tech process, the system’s elegance and efficiency was evident to everyone, with the musical director, the technical staff, Blue Men and local producers all remarking that the sound was the clearest, full-range system they had heard.
After the Australian production finished, the company started looking at other opportunities to recreate this experience. The Las Vegas production was a natural fit.
Excitement & Impact
In September, 2011, when I joined Blue Man, my goal was to bring consistency to our productions around the world. In this quest I’ve experimented with everything from microphones and console choices to loudspeaker selections.
My ultimate goal is to convey the excitement and impact of Blue Men performances at more than 64 shows a week at eight sites around the world, as well as numerous special events. Shows are presented at venues ranging from the 300-seater Astor Playhouse in New York City to a special one-off production at the Hollywood Bowl for more than 17,000.
Left to right, Tony Pittsley (head of audio for the Orlando production), author Marcus Ross (resident audio supervisor), and Jesse Stevens (head of audio for the Las Vegas production) at the DiGiCo SD7 console at front of house.
With similar content across all productions, but different needs in each venue, I find that I need to keep an open mind and consider the unique needs of each space. With a PA system, my focus is on SPL, bandwidth, coverage, polar stability and any physical limitations that might exist.
The musical composition for Blue Man shows is very dynamic and contains a significant amount of bandwidth. Choosing a loudspeaker system that has the ability to translate the entire bandwidth clearly throughout a large dynamic range is necessary for the blue men to convey both their subtle humor and high energy to the audience.
The transient response of the mix is what makes these shows far different than other artists I’ve worked with. This is instantly noticeable with Blue Man instruments, ranging from the acoustical PVC instruments to the electronic MIDI-triggered backpacks. The amount of drums in the show also determines the need to be able to handle transients.
The main system also needs to be able to reproduce unique and typical string instruments: zither, stick, guitar and bass. With such complex musical content, it becomes very important that every aspect of the system supports the show and does not impede the performance.
Knowing In Advance
The mix volume for the Las Vegas production of Blue Man Group spans from 80 dB to 105 dB (A-weighted). To insure sufficient headroom, the specification for the new PA was established as 108 dBA (RMS) at front of house with a peak output of at least 118 dBA.
Establishing a target before selecting the box count or type helps me make sure the system has enough resources for the content of the show. To me, selecting a specification for output of the PA is the same as selecting a mic for an instrument: knowing in advance the SPL capability of the system means clipping or limiting of the system will not happen.
The coverage target for the theater was +/- 3 dB from front of house in both A-weighted SPL and response. With a long throw of close to 100 feet and a short throw just under 20 feet for a differential of five times from front to back, this venue is very well suited to a line source array. This is just over two doublings of distance; it would be possible to have no more than 6 dB of loss from front to back, and with proper angle selection, less than 6 dB seemed doable without breaking the line into segments.
The combination of coverage and size limitations really dictated that a modular line source array would be the right solution. By segmenting the low-frequency component from the main element, it allows for a reduction in element size and an increase in resolution. To deal with the limited vertical space and coverage demands, it was a far better solution than a large-format enclosure with a 12- or 15-inch LF driver.
Blue Man Group extending tubes (and boundries).
Further, having already successfully deployed KARA in Australia, I knew it would be a good fit. It was more than capable of delivering the dynamic range and response the show requires, and being smaller than the previous system, it would not be limited physically in the space.
A nice byproduct of the smaller form factor is that I was able to move the arrays further offstage and rotate them more toward center, keeping reflections off the architecture and allowing for a larger stereo field.
Using L-Acoustics SOUNDVISION modeling software, I determined that 15 per side of KARAi elements would be able to achieve the SPL target and almost perfectly meet the coverage goals.
This approach reduced the overall vertical size of the arrays, allowing them to be positioned slightly lower overall to cover almost every row in the theater with minimal shadowing from scenic and architectural elements. It also meant a reduced need for fills.
With the limited time for the transition, it was essential that all variables were considered in advance of the install. The software modeling also helped me ease the concerns of the production team.
I wanted the main system to be responsible for the entire effective musical bandwidth. By doing this, the coherence problem of the mains and subs in different locations becomes a non-issue, and the buildup of LF in the first few rows of seating with ground stacked sub woofers is avoided.
With any traditionally deployed system, having the subs in a different physical location makes it impossible to time align the two across the entire space. This can be less of a problem if the audience is only on one plane, like a ballroom or a festival, but it becomes exceptionally difficult to find a decent compromise in a theater space when the seating sections are on multiple planes.
By using the main arrays to reproduce the full range it becomes possible to have a uniform tonal balance across the entire audience as opposed to a significant buildup of LF in the first few rows, due to the proximity of the seats to the loudspeakers. To achieve these two goals, lines of six SB18i subwoofers are flown directly beside the main arrays, extending response down to 32 Hz.
And with the SB18i having as much output as most double 18-inch subs, we’re able to produce more than 95 percent of the show’s musical content from the arrays and subs.
The few fills needed to supplement the mains are L-Acoustics enclosures, either coaxial point source or constant curvature line source boxes. Having the same voicing across all the loudspeakers in the system reduces complexity in the tuning process, and not having to spend as much time unifying the response of the fills allowed me to increase the time spent on the creative portion of the show.
A look at the main arrays as well as the split center cluster deployed in the main system overhaul at the Blue Man Theater.
Within SOUNDVISION modeling, I was able to ensure that loudspeaker resources and arrival times between the mains and fills would be supportive of each other and not pose a problem in headroom or imaging. For front fill, five very-compact 5XT loudspeakers are fit into the lip of the stage, also with a pair of 8XTs just offstage. The goal was to pull the image down from the flow arrays to the stage and support the SPL in the first few rows.
Ten more 8XTs function as under-balcony fills, while dual ARCS FOCUS enhance coverage to the last three rows of seating in the rear of the balcony. In the end, the delay times, gain settings and EQ provided by the software were almost perfectly matched to what was measured onsite during the calibration of the system. The result is very homogeneous coverage across the entire venue with the SPL difference well within the target.
For enhanced effects purposes, four SB28 dual-18-inch subwoofers are positioned beneath the stage, along with a dozen 12XTi coaxial point-source boxes overhead, a pair of ARCS II upstage/center, and a split center cluster of six ARCS IIs. The SB28s are housed in custom bunkers directly attached to the floor, and with the ability to reproduce down to 25 Hz, they provide the infrasonic portion of the show, really focusing on the 25-50 Hz region.
The upstage/center pair of ARCS IIs, which are flown, foster imaging effects. Thanks to the razor-sharp coverage of the ARCS II, I was able to get greater SPL without affecting the performers that are located beside and below the array. The dozen 12XTi for effects purposes supply very high output and are also passive, reducing the need for additional wiring in our marathon install.
The split center cluster of six ARCS IIs, which handles many of the vocal channels, posed an interesting problem. The center location in the theater is not available due to a scenic element, so the choice was to either shoot sound through several truss elements or split the cluster into two parts.
Again, due to the very tight coverage pattern of the ARCS IIs, I was able to segment the coverage of the center cluster while avoiding comb filtering between the two arrays.
On the electronics side, all amplification and DSP was simplified into one platform and re-located, with 18 L-Acoustics amplified controllers deployed at three locations around the theater. LA NETWORK MANAGER provides the ability to compensate the response for array size, curvature and atmospheric conditions, while also providing plenty of EQ for room-specific issues. In the end only a couple of filters were needed in any part of the system.
Starting at 10 pm on Tuesday, we removed the previous loudspeakers, amplifiers, DSP and cable, and working with our integrator, Clearwing Productions (Phoenix, Milwaukee), the new system elements were all installed and tested by 8 am. Following a rest period and fortified with plenty of coffee, we were back to work by 5 pm that same day, calibrating the system with the help of Scott Sugden from L-Acoustics we finished before break.
One of the two KARAi and SB18 flown array sets.
As noted, the measured results of the system were almost spot-on with the predictions from SOUNDVISION. Within three hours, the system response was unified and the adjustments required were limited to small time-alignment changes and managing the response of the system in the room.
By 9 am Thursday morning, it was time for sound check. In less than 35 hours, the team had installed 87 loudspeakers at 44 locations in the theater, wired and tested 72 amplifier/controller channels, tuned the PA… and gotten some sleep!
From the first downbeat in sound check it was noticeable that all of the hard work was worth it. Every fader I brought up felt as if I was mixing on nearfield monitors in a studio, not a PA at 70 feet away in a 1,500-seat theater. Having made many adjustments to shows over the past several years for Blue Man Group, this has been the single biggest leap in performance the show has seen.
I’ll close with the reaction of senior music director Byron Estep: “The L-Acoustics system handles high volume and density perfectly, without losing clarity in the transients or changing the tonal character of the mix as the musical dynamics change. Our performers and mix engineers have been extremely happy with them and feel that they accurately translate the choices they make during a performance.
“With more than 20 years of experience working on shows and listening to different systems in different rooms, I can say without hesitation that L-Acoustics loudspeakers sound the best and provide the most musical listening experience for our audience.”