Modex Plate type 2

Pressure based bass trap – performance from 35 Hz till 100 Hz


The RPG Modex Plate 2 is a high efficient bass trap with a shallow wall profile. Perfect to place on walls or corners where one does not want something to build much out.

Performance and design:
RPG reports a performance from 35-100 Hz

When we look at the measurements (measured independently by the Fraunhoder institute), we see that Modex Plate is primarily highly effective between 40-70 Hz. Below 40 Hz the effect quickly drops, however, above 70 Hz there’s still efficient performance. Take notice that these measurements are trustworthy compared to what’s often common in the industry. They are measured by impedance tube, which is a highly accurate measuring method for low frequencies.

Blue graph is Modex Plate type 2. Red is is Modex Plate.


Traditional porous material become ineffective at low frequencies and needs a significant surface depth and size to work well because the velocity of sound is zero at the surface. This steals valuable space in the room and makes the room sound less spacious. Modex Plate is VPR bass absorbent, a patented system.

A VPR bass trap is pressure based and absorbs very effectively low in frequency despite having a shallow profile. VPR consists of a damped steel plate system. This works in a mass-spring manner. The metal plate provides pistonic absorption by vibrating against the “spring” of the porous backing. The bending modes of the free moving plate are heavily damped by the proprietary adhesive coupling with the porous backing. Mid-frequency sound waves diffract around the plate’s edges to be propagated and, thus, dissipated in the deep passive porous absorber layer. The result is a bass trap offering both low and broad bandwidth effect.

More info here.

Bass builds up in corners. Trihedral corners are most often the most important places to treat. However, where the floor meets the wall and wall meets the ceiling are also corners. For correct and optimal placement in such places, measurements are needed. To measure properly before and after installation is important in order to achieve the best result. Usually several units are required for a considerable effect due to the size of low wavelengths and several pressure points in the room.

Dimension and weight:
1500 (height) x100 (width) x110 (depth) mm
Modex Plate 2 can also be mounted vertically (landscape)

Weight: 32 kg

Modex Platex 2 comes in white powder coat which is very discrete looking. Fabric covering in many different kinds is available as well.

Note that installation requires two persons. The integrated wall bracket needs to be attached securely to the wall/studs. The Modex Plate is then lifted on to the bracket.

When there’s a mopboard/baseboard, we still recommend to mount Modex Plate 2 so it touches the floor. The reason is because the pressure is high where the surfaces meet, thus placing it above can compromise some performance. An option here to use a plywood panel behind the Modex Plate 2 to fill in the air gap.