The RealDiff HDR is a two-dimensional QRD with a low frequency cutoff of 1000Hz and a prime number 13 design criteria. Designed to retrofit into conventional 2D designs, the RealDiff HDR exceeds the specifications of other manufacturers due to its higher sequence design. Two-dimensional diffusion ensures equal scattering/diffusion in both the horizontal and vertical planes. This is ideal for concert venues, recording studios, listening rooms and other environments where equal dispersion of diffuse frequencies is desirable. Additionally, the unique mounting method of the RealDiff series of diffusers means you get the job done faster and more precise than ever.