Ceiling Speaker Calculator

To calculate the number of ceiling speakers required for your project, enter the room dimensions, Extron ceiling speaker model, anticipated type of playback content, and allowable variance in sound level between speakers. Results can be viewed and printed by selecting the VIEW/PRINT COVERAGE MAP button in the Results section. The Ceiling Speaker Calculator also determines the amplifier power necessary to drive the speakers.

  • Select Unit of Distance Measurement

  • Must be a number equal or greater than 1.

  • Must be a number equal or greater than 1.

Advanced Options
  • Numbers 0-6 only.

  • Integers 0-90 Only.

  • Integers 0-50 Only.

  • Must be greater than Mininum Needed Level.

    Must be an integer not exceeding 150 dB.


The recommended cable for distributed speakers systems with cable runs under 100’ (30M) is Extron SPK 16, 16 AWG Speaker Cable. For runs over 100’ (30M), use SPK 14, 14 AWG Speaker Cable.

Sound system designers and sales engineers need to know how many ceiling speakers are required for proper coverage in a given application. Each environment is different based on the room dimensions and ambient noise. Consideration must be given to the listener height, audio program content, desired SPL - sound pressure level, and how much the client will tolerate sound pressure level variances throughout the space. Since speakers are often tailored for specific applications, their design and performance play a major role in determining quantities and positioning.

This audio tool utilizes a database of speaker coverage angle values for Extron ceiling speakers, based on the type of audio content and amount of SPL attenuation. Speaker performance data for traditional polar plots were normalized and then linearized onto a horizontal plane to calculate sound pressure levels for standing or seated listeners. This tool also provides power recommendations and transformer tap settings based on speaker sensitivity data and desired SPLs.

  • RC = (HC - HL) tan (A)
  • DC = (HC - HL) / cos (A)
  • ΔLA = 20 log [DR / (HC - HL)]
  • ΔLE = 20 log (DR / DC)
  • LMINREF = LMIN - ΔLE + Isobar


  • RC = Radius at coverage angle and listening plane
  • HC = Ceiling height
  • HL = Listener height
  • A = Coverage angle at isobar
  • DC = Distance from speaker at coverage angle and listening plane
  • ΔLA = Distance loss for listener on-axis (inverse square law)
  • DR = 1 meter or 3.28 feet reference distance
  • ΔLE = Distance loss for listener at isobar
  • LMINREF = Minimum target level on-axis at reference distance
  • LMIN = Minimum needed level for listener at isobar
  • Isobar = Boundary with a specified SPL attenuation
  • LMAXREF = Maximum target level on-axis at reference distance
  • LMAX = Maximum target level for listener on-axis