Programming prowess

AUTHOR: Inavate

Beware of the misconception that providing sound engineering for a few conference rooms is a straightforward task. The complete new installation of complex audio and media technology at the Convention Centre of the Swissôtel Zurich is a good example of the impressive flexibility of audio DSP systems.

The Swissôtel in Zurich is a large top class hotel with 347 rooms on 31 floors in the Oerlikon district of Zurich. In 2007, the Convention Centre on the first floor was refurbished and completely re-equipped with new technology, so that the hotel now probably boasts the most modern conference centre in Zurich. Here, Deutschschweiz and Westschweiz (as the German and French speaking parts of Switzerland are referred to locally) cover only a few hundred square meters. In this case the names refer to the two suites of conference rooms, which themselves are named after cities in the two respective regions. A generous foyer with an exclusive atmosphere connects the two areas, which house three large and five smaller conference rooms. The highly flexible space concept allows the rooms to be combined or divided into a number of configurations - from a small conference room, which operates independently of the events in the other rooms, through to a large 650 m² hall holding up to 800 people. At the same time, this concept represents a real challenge in terms of the media technology installed, which of course has to be seamlessly adaptable to the room configuration selected. Moreover, this must normally be possible without specialised technical personnel.

The contractor for the concept, planning and installation of the complete audio and video technology as well as programming of the AMX remote control solution was the communications technology specialist Kilchenmann Telematik. External support was called in for the complex programming of the five Yamaha DME64N DSP systems installed: Andreas Baumann, Managing Director of Mediensystemhaus in Zurich, was entrusted the task of providing sophisticated scenarios for every imaginable room configuration.

These can be easily recalled via AMX NXT 1200V touch panels installed in each room during everyday conference proceedings. The user merely has to press a button in order to activate a complex background signal processing set-up consisting of routing, equalisation, delay compensation, dynamics processing and many other components, which is fully implemented in the DME64N units.

Three separate DME64N units are responsible for the larger rooms Bern, Basel and Zurich, which together cover some 650 square metres in the Deutschschweiz area. The five rooms in the approximately 300-square metre Westschweiz area are served by a further two DME64Ns. The combined DSP performance of the five DMEs, which are connected to one another and to the other audio components via an EtherSound audio network, ensures optimum acoustic conditions in every situation – regardless of whether a conference with a complicated microphone installation or a video presentation are taking place.

The audio chain begins with a range of DVD, CD and card reading sources from Panasonic, Sony and Marantz respectively, as well as a comprehensive wireless microphone solution from Shure’s UHF-R range. After being passed by the Yamaha consoles, and DME, the sound is sent both to a Bose amplifier and speaker combo comprising Entero series amplifiers and MA or Freespace ceiling speakers, and an Ampetronic ILD1000 induction loop system. In the smaller rooms, Entero 840 amplifiers drive the subs, with Cloud CXA 450+ amps running the HF / mid-range.

The larger conference rooms are supplied with more amplification as well as feedback suppression systems also provided by Shure.

Andre Fluri, who was Kilchenmann’s Project Manager gave more detail about the system design: “We actually provided to separate AV systems - one governing the small rooms, and one for the big three. As well as the fixed solution there is also a mobile AV cart, with its own mixer and media sources. All the audio signals within the conference centre are fully transferable via the Ethersound network between the DME units.”

Running alongside the sound system is a complete A-V solution. The small rooms use MVX 88 VGA mixers and MAV Plus 128 AV matrixes, both from Extron. These serve Panasonic PT D5600E or PT D 3500E projectors. The larger conference rooms have MVX 128 VGA mixers and MAV Plus 168 matrixes to handle more options, as well as being equipped with the beefier PT D 7700E-K 7,000 lumens projector. If the three large rooms are combined to their maximum size, a 10,000 lumens PT D 10,000E projector is provided.

These days, a professional audio solution for a conference centre must work perfectly in standard situations even when no engineer is sitting at the desk. At the Swissôtel Zurich Convention Centre, this is ensured through sophisticated programming by Kilchenmann of the AMX room control, operated by touch panels, which are installed in each of the eight rooms, as well as the DME units, which are controlled using the touch panels via RS232. The significant decisions with regard to the result are made by the system depending on the activated room configuration and the required scenario. The system, for example, "knows" where in the room the speaker giving the presentation is located, controls the priority and propagation delay of the individual loudspeaker groups and assigns the manual volume controls on the touch panel to the correct signal outputs. The video/data projector, projection screen, lights and air conditioning are also made accessible to the user in accordance with the selected configuration.

The programming by Andreas Baumann with the aid of Yamaha’s "Designer" software of the five DME64N units for the Swissôtel Zurich Convention Centre took several weeks and, the company believes It is possibly among the complex DME-programs ever realised. As so often, things get really complicated when everything needs to be as simple as possible in the end. The solution for the Deutschschweiz area was comparatively easy to implement, as each room is equipped with a DME64N, which is controlled via the appropriate pre-sets with the necessary matrixing.

The task becomes trickier when a unit is responsible for several rooms, as is the case in the Westschweiz area. If the units are used both independently and simultaneously for different purposes, the simple switching of pre-sets is no longer an option as this could for example lead to undesirable signal interruptions in another room controlled by the same engine. Andreas Baumann explains, "The greatest challenge during programming of the Westschweiz area was to enable all the required scenarios to be called up without modifying the parameters for the rooms which were not to be affected. We solved this problem via matrices, and have utilised the processing power of the two DME64Ns as efficiently as possible."

The assignment of the individual signal processing processes to the individual DSP modules of the DME64N represented a problem for the Westschweiz area, so that his task could not be performed in the usual manner by means of an automatic compiler.

During programming, Andreas Baumann employed several user modules in the Designer, in order to keep the layout as clear as possible. These user modules are independent switching blocks which, in contrast to the many pre-set signal processing options available in Designer, can be freely assigned by the user to the required modules, for example for equalisation and dynamics processing. As they combine several individual modules in a “black box”, and only show their contents when double clicked, they contribute significantly to simplifying the overall layout. In this manner, for instance, Andreas Baumann provided an input module for each room, which includes components such as microphone signal processing, a printer, matrixing and summation. On the output side, the input modules provide the system with a stereo sum of the media involved as well as a mono sum of the microphone signals.

A further user module defines which media and microphone sums from the five rooms have to be linked together in the various scenarios. For instance, if three rooms are joined together for an event, the levels of just these rooms have to be controlled in unison when accessed by the user, while the remaining rooms remain unaffected. The output signals are then supplied via output matrices for each room and a source selector for each of the three sums to an individual speaker processing circuit integrated in the DME64N, for the loudspeakers in use. In total, the DME programming for the Westschweiz area comprises more than 250 individual modules.

And all this to achieve a single, but highly desirable goal: Unintelligible speeches, whining microphones and surprise acoustic attacks at disco volumes are annoyances which the guests of the Swissôtel Zurich Convention Centre will definitely be spared from in the future...