QRDesigner · DeGrandis Works

Define the diffuser

Choose the QRD order and fabrication geometry.

Design Prime order N

Construction readout

Well depth is measured from the maximum face plane toward the back.

Units Speed of sound

m/s

Maximum active relief Back padding / backspacing Panel width 1D length / extrusion

Well dividersInclude internal divider thickness in clear-aperture calculations. Organic mode disables only the internal grid. Side wallsAdd independent full-perimeter outer walls at the same construction thickness in both 1D and 2D. Divider / wall thickness

Geometry variants

Shift preserves the sequence. Random preserves the calculated value set but changes placement.

Random well distributionTurning on creates a new randomized order.

Invert ResidueCreates the structural inverse of the calculated residue field while preserving the same depth quantum: low becomes high and high becomes low.

Expand GeometryAdd the cyclic return position: N+1 wells in 1D, or an N+1 by N+1 return row/column in 2D. OrganicCubic / bicubic center interpolation. Equal adjacent centers merge to a midpoint spline knot. Dividers disabled.

Shop interpretation

The active relief is the distance between the highest and lowest reflecting surfaces. Back padding/backspacing is a separate backing layer: it contributes to total device depth, but block-height values are the physical cut lengths above that backing and never include the padding.

Live QRD geometry

N7 canonical 1D quadratic-residue profile.

Renderer initializing…

Shift sequence X 0

Calculated construction

Dimensions, sequence, bandwidth estimates, and build schedule.

QRD characteristics

Well schedule

Sequence

1D uses sₙ = n² mod N. 2D uses sₓᵧ = (x² + y²) mod N. Invert Residue mirrors values around the canonical maximum without changing the depth quantum. Expand Geometry adds the cyclic return position without changing prime order N.

Frequency estimate

Design frequency is derived from the depth quantum. The upper guideline uses the clear well aperture and c / (2w). These are preliminary design bounds, not a prediction of a room's measured diffusion coefficient.

Organic mode

Surface values are interpolated through cell centers. Organic geometry is resampled at five subdivisions per cell interval and rendered as a triangular mesh; adjacent equal centers merge to their shared midpoint. The surface sits above the specified back padding, while all perimeter walls close to the true rear face of the finished device.

Construction output

Construction geometry report

Creates the full DeGrandis Works PDF with geometry, dimensions, frequency estimates, notes, and the complete indexed build schedule.

3D fabrication output

Export Geometry (STL)

Exports the exact final closed mesh as one full-scale watertight binary STL. Because STL has no unit metadata, physical dimensions are converted to millimetres for standard 1:1 slicer import.