LENRD stands for Low-End Node Reduction Device. As you may know, a resonance bump in a room's frequency response is called a room node.

The MegaLENRD Bass Trap is just a bigger version of the original best-selling Bass Trap. At twice the width (extending 2" along each wall, not 1" like the standard LENRD), the MegaLENRD is substantial enough to handle low-frequency problems in rooms of any size. It is the only broadband absorber effective below 50hz! Churches and critical listening facilties rave about the results provided by MegaLENRD.