A Martin Audio OmniLine system has been installed in the Ivor Crewe Lecture Hall (ICLH) at Essex University, supplied by LMC Audio and installed by Scan Audio.
The decision was endorsed by Tessa Rogowski, head of customer services - Information Systems at Essex University.
“I first saw the product at ISE and spoke with technical staff from Martin Audio about the specific problems we have with the 1,000 seat lecture theater, namely hard surfaces and the fact that the only place to hang speakers was behind the microphones, causing problems with feedback,” said Rogowski.
Tessa continued, “There was no question in my mind that this needed to be solved once and for all. Martin Audio were the first people who actually appeared to understand my problems, and had the technology to ensure that the installation would be carried out correctly, the first time.”
The resulting OmniLine sale of 64 elements was handled by LMC Audio London, where technical sales supervisor, Sam Simon-Norris, oversaw the project.
Following an initial visit from Martin Audio’s Peter Child to discuss OmniLine, it quickly became obvious to him that this was the perfect system to install at the ICLH. “With fantastic sound and sleek styling, I could see that it would complement the contemporary nature of the building brilliantly,” Simon-Norris stated.
The OmniLine system will primarily be used for voice amplification in the theater, which is used for high profile graduation ceremonies, conferences and lectures. However, a further challenge is that the theater can also split into two self-contained 500-seat spaces when the positioning of the speakers would automatically change, since they are hung on the walls that would move during the transformation.
Nigel Meddemmen, Martin Audio sales support, addressed the challenge by carrying out venue predictions as an accurate 2D slice using the OmniLine software. The calculations enabled him to position the arrays to ensure best possible response and generate the required rigging, inter-module angles and equalization. These peculiar challenges, he noted, “Actually made OmniLine an excellent choice.”
Other challenges included the use of a variety of microphones in front of the PA system, including tricky omnidirectional lavalier mics, which tend to be favored by university lecturers — plus the insistence on wall-mounting the arrays since the roof structure had not been rated for a flown system.
The biggest problem, however, was the fact that the rear walls of the hall move, splitting the auditorium via a central removable divide when it needs to open up. A total of four OmniLine arrays were specified to cover each of the two sides, yet maintain pattern control across exactly the same area when the room is functioning as a single large space. However, the front wall in each of the two halves is hinged, and when moved backwards, it would swing the outside arrays inward to leave gaps in the coverage at the sides while producing a troublesome coverage overlap in the center between the two ‘inner’ arrays.
The solution was to fix the vertical coverage of the arrays while leaving a degree of play in the horizontal alignment, which would normally be tightened off once commissioned to prevent any movement. An ‘angle stop’ system was therefore designed to slot behind the standard OmniLine wall mount brackets, to make it easy to accurately reposition the arrays when the room configuration changes.
“Nigel’s solution for overcoming the two-zone problem was as ingenious as it was practical, utilizing an additional bracket to allow the arrays to be swung from one position to another, giving optimum coverage in both modes," said Sam Simon-Norris. "This really was a breakthrough for the project, and left us with no doubts that this system would be the perfect choice for the ICLH.”
For the installation itself, Simon-Norris chose long-standing LMC Audio client Scan Audio to carry out the work. The company’s MD, William (Dee) Couchman commented, “We have worked with LMC since the early 1990’s and have always been well supported with great product selection, support and demonstration equipment when needed. We had previously worked successfully together on projects for other educational institutions, and while the University of Essex was new to us, the project looked particularly interesting and we were keen to try out the new compact OmniLine system.”
The installation itself was carried out over four days, including one day to decommission the existing large custom column speakers and a small line array.
Couchman confirmed, “The main challenges included fitting the four line arrays of 16 OmniLine modules to the two large moveable projection walls. The tops of the arrays were only a few inches beneath the stage ceiling area so we used specialized hoist equipment to precisely move these into position above the supporting brackets while avoiding damage to the projection surface.
“The setting provided by the design software required only minor adjustment to produce a clear intelligible sound for this mainly speech-based reinforcement system,” he continued. “Music reproduction was surprisingly full range from such a compact line array, which blended very well with the interior of the hall.”
In addition to solving the University’s sound problems, Nigel Meddemmen noted that OmniLine is also visually unobtrusive, the curved lines and neutral grey color helping the system to blend, and not detract from the focus of the venue, in this case the university lecturers.
All of which is a source of great satisfaction for Tessa Rogowski. “It is exactly what I was hoping for,” she said. “Clear vocal reproduction even at the back of the hall in the seats positioned immediately in front of a significantly noisy HVAC outlet. And there is no feedback.
“From those with experience of the previously appalling sound, when they entered the room this time and we turned on the volume, they universally walked round the hall with silly grins on their faces. Sad though this is, we don’t get compliments, we have just stopped getting complaints—and trust me this makes it more than worthwhile.
“As for the installation process. I was most impressed. We could only give the installation team the smallest time frame to undertake the work—as the hall is booked at least six months in advance—and despite this all the work was completed on time.”