Define the listening brief
Floor area alone does not determine transducer count. Background music, industrial paging and conference speech have different requirements. Establish the use, ambient noise and occupied listening area first.
Mark seating and circulation on the plan. A stockroom, quiet corridor and sales floor need not share a level or layout density. Zoning allows each area to be controlled independently.
Use height above the listening plane
For a downward-facing transducer, use the distance from the installation to the listening plane, rather than floor-to-ceiling height. A 4 m mounting height above a 1.2 m listening plane gives an effective height of 2.8 m.
A simple geometric model gives the radius below. At 2.8 m effective height and a 90° full angle, the geometric radius is about 2.8 m. This footprint does not guarantee uniform sound pressure level.
r = h × tan(θ / 2)Read coverage at a relevant frequency
Directivity can vary with frequency. A single angle without its frequency and measurement criterion cannot describe every band. Check the selected model’s data source and frequency in the calculator.
Speech requires more than audibility: signal-to-noise ratio and room reflections affect intelligibility. Music also requires spectral balance and controlled level variation across the space.
Coordinate the layout with architecture
Coordinate initial positions with lighting, ventilation, beams and cable routes. In exposed ceiling architecture, pendant mounting may sit below the structure; use the actual mounting height.
- Enter usable room dimensions and actual mounting height.
- Locate listeners and obstructions on the plan.
- Compare coverage as the model and frequency change.
- Check the result against line load, installation constraints and field measurements.
Prepare an installation brief
Prepare a dimensioned plan, surface finishes, mounting heights, zone uses and cable information. Calculator output starts the design discussion; final equipment selection also depends on installation constraints.