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Acoustic Drapes

Acoustic drapes are essentially sound absorbers and are used to control reverberation. Acoustic drapes can be installed as static elements or tracked to allow for adjustment of absorption and exposure of a reflective surface behind.

Positioning, fabric weight, weave and fullness as well as spacing from reflective surfaces all affect absorption efficiency.


Medium to heavyweight fabrics such as wool and velvet are preferred. Acoustic drapes are generally headed at 100% fullness. Acoustic drapes are more effective within a certain frequency range; typically 500 -2000Hz, peaking at around 1000Hz.


Acoustic drapes are not generally used to stop noise transmission, however, with careful planning, acoustic curtains can offer some degree of sound transmission loss. Limp high mass fabrics are generally used. The effectiveness of such drapes is dependent on good sealing and the nature of the walls, ceiling and floor construction of the surrounding area. Sound absorption drapes are not able to significantly reduce noise transmission between two adjacent spaces; they are rather designed to improve sound quality and reduce reverberation levels within the room that they are installed. 


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Material Thickness

The material must be thick and highly porous. The thicker the absorption material, the more effective it will be against a longer wavelength (lower frequency) of sound. In order to be effective against bass frequencies, sound-absorbing acoustical panels typically need to be at least 2-5cm thick. Since it would not be practical to have a 5cm thick curtain, you must select the thickest, heaviest fabric your budget will allow.


In order to improve the low and mid-frequency sound absorption performance of your acoustical curtain, the material must be pleated. This will cause the fabric to be gathered such that it loops in and out. The pleating should be as deep as possible in order to expose more sound-absorbing surface, thus increasing effective thickness and improving low-frequency sound attenuation. Minimum pleating at 50% fullness is required; 100% fullness is recommended.


The means and mechanism of mounting will not affect acoustical performance but does determine how easy it will be to open and close the drapery.

Motorized winching systems are easy to operate but very expensive. For most applications, simple manually-operated rigging is the most cost effective option. STM Studio Supplies consultants will be able to guide you on the appropriate mounting hardware.

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