De Doelen Orchestrate with Mini

De Doelen, Rotterdam’s premier concert and congress hall complex, recently embarked on a redevelopment programme that would take it through to 2009.

The concert and congress halls collectively host more than 650,000 visitors each year (with the ‘Concertgebouw’ itself staging 600 concerts — from classical to world music and jazz).

Built in 1966 it is considered acoustically to be one of the finest modern concert halls in the world. With the Rotterdam Philharmonic Orchestra also resident, the pressure on head technicians, Frank van Donkersgoed and Bram Ruitenbeek, to remain sensitive to the building parameters while specifying the system that would best meet the requirements of an expanding programme, was paramount.

Management at de Doelen wanted to advance certain elements of the long-term renovation plan — notably the stage, infrared provision and the loudspeaker system.

The main 2,200 capacity concert hall had been running off a centre cluster PA — which van Donkersgoed says had been designed principally for speech amplification, but was often misused as part of a PA system (in combination with some delay speakers and heavy EQ).

The criteria was to aim for 105dB on each seat — with a coverage of 80% of the seating with ±3dB (and ±6dB over the remaining 20%). “We wanted a pretty high sound pressure level but we also had to meet the requirements for speech intelligibility,” he reports.

The ceiling in the 60m x 30m room has both an architectural and acoustic function in respect of the reverberation times on the low frequencies. And with other changes proposed for the ceiling design in 2009 it presented a compelling case for a mini line array solution. Leading acoustic advisers Peutz agreed.

Five internationally-recognised brands were put forward — with one prerequisite. “It was important that the house technicians had a system that they liked — in audio engineering that is vital.”

The evaluation was rigorous. The five brands were reduced to three with each given the chance to operate in real world conditions in the main hall. “We wanted to give them a chance to do a concert here prior to the shoot out, and we also visited sites in Holland for remote evaluation,” says the venue’s head technician. In the case of Martin Audio, Frank van Donkersgoed listened to the W8LC installed by TM Audio at Oosterpoort in Groningen.

Eventually de Doelen backed their own test results. “With the Martin Audio mini line array we could do everything we wanted,” states Frank. “Our own technicians had a preference for Martin Audio and that was also important.”

A Peavey MediaMatrix NION 6 networkable I/O device has been used to store various sound structures as system presets — depending on the occasion. All the speaker processing itself is stored in XTA devices.

The first install versions of the W8LM rolled off production and the prototype system was installed (11 enclosures per side) — but this would change once the W8LMD downfill boxes became available; today nine W8LM’s, with a single W8LMD at the base, form each hang.

The configuration was vital as the architecture and resulting sound pattern are far from straightforward. The audio has to be projected through the raked stalls and up to the tribunes on a fairly steep slope over a distance of 50 metres (from front of stage to the end of the hall). On the sides there are a number of loggia boxes — effectively openings forged into the side walls. But the biggest problem (as at London’s Royal Albert Hall) is the seating at the rear of the stage, where the Baroque pipe organ is situated.

“Initially we were not happy with the solution we had for the back of the hall, so we came up with a new assembly using Martin Audio Blackline F10’s, one on each rig,” says TM Audio’s project manager, Reinier Bruijns. “These were intended for side and rear fills — but we felt it would reflect too much sound onto the stage when it hit the marbled walls at the back of the stage, so we changed the back ring to a line array, using two of the new W8LMD downfills.” This approach has proven to be an unqualified success.

Thus reconfigured, the two hangs are positioned fairly close together on motorised flying frames (customised by TM Audio). The two ‘bananas’ lower via a 5-metre vertical excursion, designed so that the view from the loggia boxes does not obscure the view of the conductor walking up to the podium. The motors, themselves, were provided by BBH, who also provided the elaborate new staging.

The system was set up using ViewPoint™ and for the final commissioning this was converted to Martin Audio’s virtual 3D modelling tool, DISPLAY™.

There are four separate amplifier feeds — dedicated to the two minis, downfill and a mobile rack — each placed close to the speakers to reduce the length of cabling.

Locked in the amp racks are MA1.6s and MA2.8s amplifiers, while the subs are powered by MA4.2s and the F10’s by MA1.3s. Loudspeaker management for the two PA hangs is courtesy of XTA DP428’s and the downfills and F10’s are under the control of an XTA DP224.

The downfills pick up from ten strategically-placed nearfield enclosures around Row 5, while the W8LM’s are then beamed into the rear stalls and upper tribunes. There are an additional three W8LM’s ground stacked with a pair of Blackline S218 subs to raise the SPL level when a band is playing.

De Doelen see many advantages with the new W8LM installation and it is now mandatory for incoming shows to plug into the house system. “We were afraid that incoming organisations would demand a big system to do the big shows — but this hasn’t happened,” confirms van Donkersgoed.