Primacoustic Cumulus

Get rid of room boominess with stylish ceiling corner traps.

The Primacoustic Cumulus is a triangular broadband acoustic corner trap that effectively absorbs sound from 125Hz and up. Designed to fit in corners where the walls and ceiling meet, the Cumulus takes advantage of the natural propagation of sound that occurs in all rooms. Sound waves follow the wall and ceiling planes and accumulate in the corners, a well known hot spot in small recording rooms or theater.

The Cumulus is amazingly compact. Each side is 24″ in length and, when in place, creates a 12″ deep air space cavity behind the panel that increases the bass absorption characteristics. Mounting Cumulus traps in a studio will generally yield a significant reduction in the problematic low-mid region while leaving the architectural design of the room virtually intact. Invisible mounting is achieved using spring-tensioned clasps and a single eye-screw. Mounting literally takes minutes and because of the reverse beveled edges Cumulus traps flush mount ‘seamlessly’ into the room esthetics.

This makes the Primacoustic Cumulus the perfect acoustic starting point for rooms such as home theaters or smaller production suits that have limited wall space and suffer from saturation of lower mid-range frequencies (known as ‘boomyness’). The strategic placement of the Cumulus in the ceiling corners plus the air cavity it creates there, helps flatten out low-mid room response.

Cumulus Details and Development

Sound travels through the air in the form of waves. It is well known that walls and ceilings act as waveguides that direct the sound waves into the corners. This is the primary reason why acousticians always start by treating the corners. In essence, you get the most performance with the least material. But even though acousticians have long identified the benefits, the difficulty of mounting acoustic panels in corners and lack of ideal mounting options have discouraged people from taking advantage of this prime room location.

The Primacoustic Cumulus presents a simple and elegant solution. It is a surprisingly basic acoustic device combined with ingenious mounting hardware. Once installed, the Cumulus looks terrific and is highly effective at reducing low-mid frequencies that are attributed to ‘boomyness’ in a room. The magic lies in both the quality of the acoustic panel, its innovative design and the corner mounting location.

The 24″ triangular Cumulus panel is made from high density 6lb per cubic foot rigid fiberglass. The same material broadcasters and world-class studios have used for years to control room acoustics. The panel is fully encapsulated within a micromesh and employs resin hardened edges. These panel treatments combine to ensure the minute glass fibers cannot escape and produce pleasing architecturally straight lines. The 2″ thick panel is then covered in an acoustically transparent fabric.

The edges of the Cumulus trap are reversed beveled and form a wedge shape that naturally transitions from the walls and ceilings to create an elegant corner trap. When mounted, the 24″ sides create an air cavity behind the panel with a depth of 12 inches. It can be determined, by using quarter wavelength calculations, that the air cavity the Cumulus creates will effectively attenuate frequencies down into the 125Hz region while the panel surface effectively absorbs high frequencies from 400Hz and up. This is what makes the Primacoustic Cumulus a broadband noise absorber.

Once in place, you will immediately notice a tighter more defined bottom end. All small rooms tend to suffer from excessive low-mids and this is exactly where the Cumulus can be most effective. Because the front panel is completely open, it also helps reduce flutter echo and standing waves.