Gothenburg’s Bethlehem Church has completed the installation of a Nexo Geo M6 compact line array, satisfying its needs for vocal clarity and aesthetic discretion.

A specialist in church audio installations, Tech 4 Event AB was called in to assess the needs of the church, and its 800-strong congregation. After analysis of the church room’s acoustics, and comparison and demonstration of various manufacturers’ solutions, Tech 4 Events CEO Björn Carlsson Events and his colleagues were agreed on the Nexo option.

‘Such a test is rewarding for the customer, in this case the church assembly,’ Carlsson says. ‘In this way, they get an opportunity to listen to different systems before choosing what to install. Not only to experience that one system sounds better than anything else, but above all in order to determine whether the systems fit into their premises and the activities that are going on there.’

The final choice rested with the church assembly, which chose the Nexo Geo M6 compact line array. Steps were taken to improve the building acoustics, such as replacing the ceiling, which helped Carlsson and his team as they set about examining the design of the sanctuary, and how its acoustics worked.

‘We used one of our most important tools, the NTI XL2 Acoustic Analyzer, which enables us to document acoustics, frequency, sound pressure and STIPA value, the assessment of speech comprehensibility in the room,’ Carlsson explains. ‘We used this measurement tool before, during and after a completed installation. Through these metrics, we could ensure a range of parameters to gauge which improvements have been made, and to verify that the requirements in the preliminary study were achieved.

‘We did several computer simulations early in the project to see exactly where the speaker system elements would be placed to get the best results. All measurements from the room were added to the system, along with data from the drawings of the church from the architect. Then we got a 3D model of the whole church room, and in this case we used Nexo’s own software, NS-1, which is a powerful and intuitive system configuration and simulation tool with a smooth drag-and-drop interface.

‘The NS-1 program enabled us to configure and optimise performance of any Nexo system by simulating its behaviour in the current location. Measured speaker data is processed together with complex mathematical data to predict SPL and delay in three dimensions. Then we could quickly and efficiently see how different speaker systems behaved in the room and how they would sound. We also found out how many speakers we needed of a particular model to solve the assignment and reach the desired end result, but above all we found out where in the room we would need to install the selected speakers for the best results. It is an extremely useful piece of software.’

Acoustics are often challenging in a church building, but an addition requirement was for a speaker system with minimal visual impact on the room.

‘We know from experience that, using the right technology, it is possible to create good sound systems which can also look nice and blend into the church room. In this case, we mounted the speaker system on a heavy concrete beam between floor and ceiling, and the assembly wanted the speakers to pick up the colour from the concrete beam. So the loudspeakers and flyware were specially painted in the RAL colour we received from the architect to blend in perfectly.’

The Nexo Geo M6 is a relatively new system that made it a little easier for the team to make an aesthetic fit: ‘The lightweight polyurethane composite cabinet is ideal for installation in design-sensitive environments. In addition, this line array also performs very well when it comes to both sound pressure and sound quality. Not only is there a wide range of mounting accessories, the system offers us as an installer and audio rental company a reliable, TÜV-certified system with very good performance. The Bethlehem system uses 18 Geo M6 modules in two arrays of nine cabinets, supplemented by two Nexo LS18 subbass. The entire system is powered by three Nexo NXAmp4x1, which brings the built-in, advanced processor that makes the system sound so good.

‘We and, more importantly, the congregation are pleased with the results in the Bethlehem Church,’ Carlsson concludes. ‘Of course, the sound quality has become much better with a steady frequency range from bass to treble, but above all speech comprehensibility has become significantly better. Every seat in the whole church must enjoy the same sound and we have managed to achieve that. In fact, there is only 2dB between the highest and lowest points in the whole church, which is a very, very good result.’