Using the correct system components and source locations is the best tool we carry for achieving great results with indoor temporary sound reinforcement systems. It’s about minimising’s strong specular reflections whilst ensuring that the direct sound to reverberant sound ratio is adequate to convey excellent speech intelligibility.
Using acoustic design software (ADA EASE) we can provide visual representations to justify our decisions to our clients.
In acoustically difficult spaces, a highly reverberant space like a church, for example. Speaker placement can only go so far in achieving the required results without having a dedicated loudspeaker for everyone!
In this situation it is the room itself which needs treating, although this is possible for temporary events it is a costly and time consuming process which requires full acoustic analysis of the space.
If the event’s budget and time scale allows then we are always happy to undertake the task of establishing what treatment is required and where.
We can provide example auralisations, in this context we refer to auralisation as information visualisation through the use of sound. I.e. actually hearing the results of acoustic treatment by using advanced software which creates a virtual means of analysing the sound within a given space.
Eample A – A church without treatment
Example A – A church with Treatment
This method involves creating the building in a CAD environment in great detail, entering all boundaries and assigning the acoustic properties of materials. It’s a lengthy process but is a major step forward in achieving the acoustic ideal. Particularly useful for fixed installations in concert halls, theatres, arena and churches.
For relatively straight forward spaces, dance halls, recording studios… etc, it is possible to carry out a basic acoustic analysis which can establish an estimated reverberation time for a given space and suggest optimum construction and finishing features to achieve the desired results.
This tool is useful in the planning stages of a new-build where planning can attain optimum room ratios to get you off to a flying start.
Outdoor events are more straight forward in regards to achieving optimum sound coverage because there are limited boundaries to cause reflections which can result in deterioration of the sound.
The principle concern with outdoor events is off site noise spill, this is a major problem for music festivals at the moment. We have developed a number of processes which can result in higher levels for the audience and lower levels off site.
Optimum Speaker Deployment
This is a simple one. For the bulk of the frequency range it is possible to use directional loudspeakers to point the sound away from sensitive areas. By using flown loudspeaker arrays it is possible to aim the speakers in both the vertical and horizontal planes so that the majority of the sound is focussed down on to the audience area with a defined “critical distance” were the direct sound drops off considerably.
Low Frequency Propagation
Ask any festival organiser or environmental health officer and they will tell you that low frequency noise spill is currently the largest concern for outdoor events. This is due to the physical size of the wavelengths. Like the saying “water will always find a way” the same is true for bass frequencies, unless, you can reduce the flow at the source.
We have carried out in-depth research into bass cancellation techniques which use the physical and electronic alignment of sources to cancel the sound propagating in a given direction.
The prediction program we use is called Mapp from Meyer Sound Laboratories. Detailed in house appraisal of the program has shown it to be very accurate in its predictions.
Low frequency sources are omni-directional, that is, sound travels equally in all directions from the source
By employing bass cancellation techniques we can reduce the sound spill in one direction by a considerable amount.
Showing that measures have been taken to control these problem frequencies will no doubt be a key asset to event coordinators.
For more information about any of our techniques relating to room acoustics and noise propagation please get in touch.