

Even though acousticians have long identified the benefits of treating the tri-corner, the difficulty of mounting acoustic panels in corners and a 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 (A). The same material broadcasters and world-class studios have used for years to control room acoustics. The panel is fully encapsulated with micromesh (B) and employs resin hardened edges (D). 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 (C). The edges of the Cumulus trap are reversed beveled and form a wedge shape (E) that flush-mounts and naturally transitions from the walls and ceilings to create an elegant corner trap.
The strategic corner placement combined with the high performance acoustic panel and cleverly created air cavity behind make the Cumulus a highly effective broadband absorber. The Cumulus is available in three neutral colors that will easily integrate with the most architecturally demanding room designs.
Each side is 24" in length and, when in place, creates a 17" deep air space cavity behind the panel that increases the bass absorption characteristics. Mounting Cumulus traps in a room 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.
Cumulus traps have been tested to meet stringent class-1 fire ratings making them suitable for use in residential and commercial spaces.

| Dimensions: | 24” (60.96cm) x 2” (5.08cm) Edges are reverse beveled. |
|---|---|
| Panel Material: | Formed, semirigid inorganic glass fibers; Density = 6.0 lbs. (2.72kg/m3) per cubic foot |
| Fabric Facing | Acoustically transparent polyester |
| Fabric Color Codes: | Black=00, Beige=03, Grey=08 |
| Order Number: | Z840-1210-xx (xx denotes color code 00=Black; 03= Beige; 08=Grey) |
| Mounting Hardware: | Eye hook, drywall anchor and spring clip included. |
| Quantity per box: | 2 units |
| Weight: | Shipping weight = 5 lbs (individual weight = 1.4 lbs (0.64 kg) |
| Full Specifications: | Cumulus Trap Engineering Data Sheet [710k] |
![]() Absorption data for surface mounted2" Broadway panel. |
![]() 2" Broadway panel with 2" air gap. |
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![]() Effect of tri-corner mounting derived by quarter wavelength calculation. |
![]() Composite absorption response for the Cumulus. |
| 100Hz | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz | |
|---|---|---|---|---|---|---|---|
| Cumulus Composite Absorption Based on 2" Broadway absorption test data, 2" air gap test data and quarter wavelegnth calulation. |
1.03 | 1.23 | 1.15 | 1.24 | 1.20 | 1.14 | 1.11 |

Test |
Class |
Flame Spread |
Smoke Density |
Test Data |
|---|---|---|---|---|
ASTM E 85-05 |
1 or A |
15 FSI |
155 SD |
|
CAN/UL-S102 |
1 or A |
15 FSC1 |
155 SD |
|
| Test data provided by Bodycote Materials Testing Inc. This method, designated as ASTM E 84-05, "Standard Method of Test for Surface Burning Characteristics of Building Materials", is used to measure and describe the response of materials, products, or assemblies to heat and flame under controlled conditions, but does not by itself incorporate all factors required for fire-hazard or fire-risk assessment of the materials, products, or assemblies under actual fire condition. | ||||