The Belltron Audio System in the Basilica of Nairobi

Date: July 01, 2019

Susceptible, flexible and clear: thoughts on sound amplification in a natural way. The circumstance of the Cathedral Basilica of the Holy Family of Nairobi in Kenya.

An increasing number of Basilicas and Cathedrals in the world are choosing Belltron Audio Systems for high quality sound reinforcement. The flexibility and the wide range of products offered by the company are increasingly known to solve the problems of acoustics in any environment.

The last challenge was tackled in the Cathedral Basilica of the Holy Family, which is also the Archbishop's residency in Nairobi.

Imposing, solid and modern, this Kenyan place of worship had a sound setback during the celebrations which gave an annoying background echo. Furthermore, the building had numerous different huge black speakers installed which were more appropriate, both in appearance and functionality, for places like discos or stadiums and totally unsuitable for a place of worship.

The word of God for the worshippers: problems and solutions

A clear voice is of fundamental importance for any type of audio reinforcement, in particular when it comes to harmonizing sounds in places of worship in which several factors such as voice, song, choir and musical instruments sooner or later are involved in events and/or functions.

It had become difficult to listen to an intelligible voice inside the Cathedral but our designers were able to create a low-impact visual installation with the highest possible acoustic performance for the Cathedral of the Holy Family.

A natural sound reinforced by an appropriate sound system can be achieved if specific provisions are taken.

The objective is difficult to achieve, especially in places of worship that have been built with particular materials and have a certain architectural style. Belltron, with its decades of experience in the ecclesiastical field, has succeeded in creating increasingly performing, precise and unique equipment for use in places of worship which other companies that build standard audio systems cannot achieve.

To obtain a natural sound reinforcement, the latter must be clear, meaning that one must not have the sensation of an echo sound or a rumbling sound, it’s the voice, song and music that must reach the assembly, guaranteeing maximum intelligibility.

The voice and the microphone

An important aspect of natural sound is to create the clearest and most understandable vocal sound possible. A clear voice is essential for any type of amplification, particularly when it comes to places of worship where people go to hear the word's message.

There is also a thin line between intelligibility and hardness. Too strong a voice is of no use to anyone. The objective to be reached is a higher volume (this is the purpose of the sound reinforcement system) but there is a rather shady side as to what is or is not appropriate to do to be able to achieve this result.

Each voice is different, which means that each voice needs personalized attention.

The correct approach is to start with subtractive equalization. Generally it is better to start by cutting off the excess frequencies related to the environment and then resort to increasing the desired frequency ranges only if still necessary. The Belltron microphones, depending on the model: for the pulpit, altar or hand held, have been specifically designed to avoid adversities and to give fullness to the voice depending on the context of use.

Amplifier, equalizer, mixer, speakers

As already explained, reverberation seemed to be the problem that we analysed. The solution offered by Belltron was that of installing the amplifier (mod. BPA-246 EA PRO) which has the appropriate performances to resolve such a situation.

All Belltron amplifiers are equipped with mixers, which allow up to 16 microphone lines to be housed.

Using the internal parametric equalizer, which has 10 audio ranges, it is possible to obtain an adjustment of the room acoustics customized for the architectural structure in which it is installed. The various parameters are conveyed to the desired areas for the projection of the sound of the voice through a digitalized electronic system. The different sources from which the sound comes (voice from the altar, pulpit and / or choir) can be adjusted to different volumes. These preamplified and individually processed audio signals are reinforced by different power amplifiers which in turn send them back to the corresponding loudspeakers located in the areas of the church where they are needed.

The antilarsen, is also incorporated in the amplifier and allows to considerably reduce the feedback.

Belltron audio systems

People who are not experts are usually scared at the thought of having to deal with unknown devices. Belltron has designed its digital audio systems with latest generation technology to be easily used by anyone who does not have a specific technical background.

For example, the volumes can be adjusted and programmed according to the number of people attending the church: whether it being a public holiday or a working day, or depending on the area where the speakers are located. This audio programming greatly facilitates the Minister who does not have to reset the parameters for each church function and who does not want to have an echoing or flat sound during the daily functions. The systems are all made with latest technology in which touch screens and remote management apps are integrated and part of all Belltron projects.

The importance of singing

Attention should be paid to the choir's microphone which requires different power-up characteristics than those of a single speaker. Using Belltron’s equipment it is possible to create a pure line (without using the antilarsen) to obtain a pure sound.

A strong gathering of people and lots of music distinguish African functions, even in the Cathedral in Nairobi. In the sanctuary, in fact, be it early in the morning or midweek, there is always a good gathering of people at all the functions. The parameters of the audio system were therefore adjusted to give body to the celebrant's voice in an environment that is always full of worshippers and the choir is free to express itself at its best in its harmony.


At the end of the work, the firm Eracle, an authorized Belltron dealer for Africa based in Nairobi, was so enthusiastic about it all that they suggested our technicians to proceed in making inspections to three other churches currently under construction in the Diocese.

"The preacher is totally content that all the parishioners can clearly hear the functions now," says the head of the Eracle firm. "We were pleased to have helped the Cathedral of the Holy Family into a new digital era and we are looking forward to using the Belltron systems in our future projects ".

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