Project Optional. Used for the PDF report header.
Room dimensions
Results
Modal distribution
Room-shape criteria
Axial frequencies — first four per axis (Hz)
| Order 1 | Order 2 | Order 3 | Order 4 |
|---|
Polarity along each axis
Listener placement check
Recommended sub layouts
How to read this Background on the inputs, the chart, the criteria, and the polarity diagrams.
About the inputs
The calculator assumes a rigid rectangular room. Length, width, and height are the only inputs — no surface treatments, damping, or RT60. Those require physics-grade material data that the Level 1 calculator can't ask for; they live in Cinema Tools' paid tools.
About the chart
The modal-distribution chart plots every resonance up to ninth order, classified by type. Axial modes (one non-zero index) are the strongest; tangential and oblique modes carry less energy. Even distribution across frequency is the goal — clusters and gaps show up as columns and stripes.
About the criteria
The four criteria score the L : W : H ratio against published envelopes. Walker and IEC 60268-13 are looser; Bolt is the strictest. Bonello looks at how evenly the lowest 48 modes spread across the third-octave bands. A room can pass one and fail another — they trade off differently.
About the polarity diagrams and sub layouts
Each polarity diagram shows where the resonance peaks and nulls sit along an axis at a given order. Listeners near a null can't hear that mode; subs placed on opposite polarity zones cancel the worst peaks. The two recommended layouts are Cinema Tools' house starting points; the paid tools optimise sub placement numerically.