Vertical Banners / Blinds

What are vertical acoustic banners?

Vertical acoustic banners (or blinds) are mainly used to flexibly provide sound absorption in spaces (i.e. make them less ‘echoey’).

They can either be:

  • hung and extended along hard vertical surfaces (walls, windows, etc) to absorb sound and reduce the sound reverberation (i.e. ‘deaden’) in the space. Their length can be adjusted depending on how much sound needs to be absorbed. Or;
  • rolled away, sometimes in a dedicated casing, to increase the sound reverberation in the space.
Fixed acoustic banners (left) and vertical banners with adjustable length - sound absorption
Vertical acoustic banners with adjustable length (right)

The banner systems are usually mounted on walls at high level or on soffits.

Vertical banner systems are usually motorized and include either one or two layers of textile.

Flat acoustic banner systems with one and two layers of textile - sound absorption - acoustics
Flat acoustic banner systems with one and two layers of textile

What materials are vertical acoustic banners made from?

The acoustic banners are usually made with seamless and porous textiles such as:

  • wool serge
  • encore velour
  • synthetic velour
  • polyester
  • wool

The weight of the materials ranges from approximately 0.1 kg/m² to 0.6 kg/m²  and some materials can be flame retardant.

What are the sound absorption characteristics of acoustic banners?

The sound absorption of acoustic banner systems range between Class C and Class B sound absorption.

It generally increases with the number of banners (See graph below).

Sound absorption coefficient of one and two flat banners (0.53kg/m²) in front of a hard surface - sound absorption - acoustics
Sound absorption coefficient of one and two flat banners (polyester, 0.53kg/m²) in front of a hard surface [1] 
With textile being a porous material, acoustic banners are better at absorbing sound at mid and high frequencies (from 500 Hz) than at low frequencies (below 250 Hz). Although, the sound absorption can be increased at low frequencies if the banners are installed within a niche [1] (See graph below).

Flat acoustic banners in a niche (left) and freely hanging (right) - sound absorption - acoustics
Flat acoustic banners in a niche (left) and freely hanging (right) [1]
Sound absorption of acoustic banner freely hanging and in a niche - acoustics
Sound absorption of acoustic banners (polyester, 0.53kg/m²) freely hanging and in a niche [1] 

What about the sustainability of acoustic curtains?

See the Environmental Product Declarations for some product examples.

Note: the above information is drawn from review of product information and the following documents:

  • [1] Enhancement of bass frequency absorption in fabric-based absorbers – Jonas Schira