Frequently asked questions

+ How do sound absorbing products work?

Most allow sound to enter the material and reduce the sound energy by suppressing the sound wave. The energy is converted to heat.

+ What are the typical frequencies of speech?

Typically, 250 Hz to 4000 Hz. To effectively absorb speech frequencies the absorber should be at least half the wavelength of the lowest frequency. This is not always practical, but absorbers should be a minimum of 25mm and preferably 40 – 50mm for meeting rooms and offices.

+ How can the ReSorb panels be cleaned?

Depending on the type of soiling, either a soft brush, vacuum cleaner or alcohol wipe will work.

+ What are the fire ratings?

We publish the fire ratings for each product, most are class 0 or class 1

+ Can you have too much sound absorption?

Yes, too much absorbing material can make a room feel “dead” sometimes uncomfortable and unnatural.

+ How can I test the reverberation time of a room?

There are apps available online that will measure the reverberation time, not always very accurate though. You will also need a noise source such as popping a balloon.

+ What is reverberation?

The multiple reflection of sound, with each reflection there is a very small change in timing creating interference of the signal, after many reflections the signal will become incoherent.

+ How is reverberation measured?

RT60 is the standard measurement, the length of time in seconds for the sound, when ceased, to reduce by 60dB. Typically we might use a sound level meter to measure and a balloon to create the noise. For a more formal measurement we would use a omni directional broadband noise source such as a dodecahedron but the balloon works for speech frequencies.

+ Will the ReSorb products improve speech privacy?

Possibly, sometimes improving the acoustics of a room reduces the volume needed on conference equipment in the room and this can improve speech privacy in adjoining spaces. Reducing the reverberation in the “listening” room can also improve the speech privacy of the “transmission” room.

+ What do the absorption classes mean?

The classes allow for a rating of absorption efficiency from A (the best) to E. Most acousticians will recommend a class A or B for meeting rooms but if there is to be a lot of material applied the class could be reduced to prevent the room being too “dead”.

+ Is the absorption location important?

Yes, in most rooms absorption should be applied to two adjacent walls, certainly applying to walls opposite glass is preferred.

+ How much material do I need?

For meetings rooms our rule of thumb for class A is the equivalent of 60% of the floor area, i.e. a room that is 5m x 3m requires 9m² of class A material. For more accuracy we can calculate the required amount for you with some details of the room(s)