In modern studio design acoustic diffusers are used to control wall reflections and create a smoothed sound environment. QRDs are designed for one frequency which might be suspicious for some users. Therefore I though about a design which uses 2 frequencies. It's shape morphs in between two possible sizes:

Acoustic diffuser with two different element sizes. Depth and height change according to frequency / period definition.


QRD - Double Architecture

Two of these designs might by joined to get a symmetric design:

Quadratic residue diffuser using 2 size definitions in complementary orientation.

Several diffusers of this shape joined to get a complete wall

You are encouraged to use the designs for private use.

 See the former article about that idea of multifrequency diffusers

 See another article about QRDs