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.