Delving deeper into Audio Visual technology – Part 2

We have been delving a little deeper into audio visual technology, through a number of interview sessions with our technical specialists. We wanted to know what questions or problems our technicians encounter in their daily work. If needed we are happy to add some theory to these answers, because sometimes it is necessary to have a little more background information to understand why a certain solution has been chosen.

We kick off the series with an interview with one of our audio technology specialists.

Topic: Audio Technology

Audio Part 2

At events, we see more attention being given to video, lighting and decoration. The most basic instrument available to us in terms of technology is sound, but this is often neglected. And yet good sound quality is essential to the success of an event. Even if you have a TEDx level speaker, if the presenter can’t be clearly heard by the audience in the back rows, the presentation is worthless. We asked our technicians what it takes to make a meeting or conference a success in terms of considering the influence of the room’s acoustics when it comes to speech transmission.

    1. You are talking about reverberation. Most people are more familiar with the word echo. Is there a difference?

Yes, reverb and echo are not the same. The difference lies in the time it takes for the sound to reach the source. Reverberation returns to the source within 0.1 seconds; anything more than 0.1 seconds is called an echo.

     2. When talking about sound in rooms, the word acoustics is often used. What are acoustics?

Acoustics are the influence that a room has on the sound and reverberation of sound. When people say “this room has poor acoustics”, they mean that the characteristics of the room are not ideal for the use they have in mind. This can apply to a stadium, for example, but also to a church, a lecture hall or a room in a hotel where meetings are held. It should be noted that there is a big difference in acoustic performance depending on the use. A concert hall is perfectly suited to the reproduction of unamplified instruments, but without modifications it is not suited to rock concerts. Pop stages and discotheques, on the other hand, are designed for maximum sound absorption and are therefore not suitable for classical reproduction.

     3. How can you adjust the acoustics of a room?

Treating or manipulating/editing the acoustics of a room can be done in different ways:
– Physical: adjusting or re-configuring and manipulating the room e.g. by adding damping or reflective materials, lowering a ceiling or moving the position of stage and/or loudspeakers.
– Artificially, by means of equipment that can edit the sound. By using signal filters that are set in the sound mixing desk, adjustments are made at a frequency level. The frequency (wavelength of the sound) that has acoustically undesirable effects can be filtered out very precisely in order to achieve good reproduction.

     4. As an AV company, can you make physical adjustments to the client’s room?

This is possible, depending on the specific situation, solutions can be applied everywhere.
ACS is a specialist in building temporary congress halls in exhibition halls and therefore has a far-reaching influence on the physical properties of these spaces. The position of the stage, loudspeakers, hanging soundproof curtains, laying down carpet and placing upholstered fabrics, ensure that reflections can be reduced.

     5. How can you make sure that the voice is audible to everyone in a room?

The audio technician has several resources at his disposal with which he converts, amplifies and refines vocal sounds.
The most important tools are the mixing desk, the equalizer and the amplifier.
– After the microphone, the mixing desk is the first stage where the sound is processed. This is where the first amplification and refinement is made, specifically for each source (= the origin of the signal).
– Then, in the mixer, all sources are mixed into 1 signal, the master signal. This signal then passes through an equalizer that adjusts the signal specifically for this room.
– Finally, the signal passes through an amplifier, where the volume can be adjusted for each speaker (group).

Do you have any specific questions about sound?
Just ask us and we will answer them in our next post. For advice you can always reach us by email or phone.