Sound Advice - acoustic fabrics
The science of sound
Improving acoustic performance is a huge subject, an entire science in its own right, but in simple terms, every material has a sound absorption coefficient, a figure which measures how much sound is reflected versus how much is absorbed. This figure lies between 0 which is total reflection, and 1 which is total absorption.
So what is alpha-w?
This absorption coefficient of a material varies according to frequency of the sound, so a standard benchmark has been developed in ISO 11654 using a range of frequencies to give the Weighted Sound Absorption Coefficient, often expressed as 'alpha-w'. This is split into classification groups A-E, with A being best absorber (alpha-w > 0.9) and E being the lowest (alpha-w = 0.15-0.25).
How does this affect my project?
Phew, that's the technical bit over with... now how do we actually improve acoustic performance in a space? Essentially by getting the maximum surface area covered by the most absorbent materials. Obviously we can't completely cover the ceiling, walls and floor with hairy acoustic panels (unless it's a recording studio), so we have a trade-off. We might need a hard floor for hygiene and cleaning purposes, and we might need glazing to bring in natural daylight - but glass and hard floors are poor absorbers, so we have to make it up elsewhere, with acoustic ceilings, panels or drapes.
What are the options?
One way is to use roller blinds with acoustic fabric, like Soprano. Soprano is a 100% Trevira CS fabric with a class C acoustic performance. Because it's a semi-open weave, Soprano still allows some view of the outside world so you don't get that claustrophobic feeling.
Another option is acoustic curtains. Wool is one of the best sound absorbers available, so wool serge curtains at 500-800gsm positioned around hard walls, can really boost acoustic performance. Decor Wool Serge is available in a range of weights and standard colours, and for larger batches, it can be dyed to the exact colour you require.
When Apple fitted out their iTunes lounge in London, Decor Systems were involved in supplying and installing an acoustic curtain around the perimeter. The 22 metre curtain track was recessed into the ceiling for a flush finish.
It featured extra heavy duty runners to support the acoustic curtain in Kvadrat Coda 2 fabric. ...