Line Array Calculator III

Predict Your Design

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Line Array Calculator (LAC) is a simulation software intended for the design and prediction of JBL VTX Line Array systems and their acoustical performance. In addition, you can also use the software with flown and ground stacked JBL VTX Subwoofer Arrays. Beyond just acoustical prediction, you can use Line Array Calculator for mechanical validation and the calculation of all weight limits and safety warnings for JBL VTX Systems.

Line Array Calculator’s Enhanced Acoustical Modeling includes color SPL mapping, 0dB Isobar and SPL attenuation modes with frequency response and SPL based on JBL’s VTX DSP presets. With it, you can place up to 8 virtual microphones in the venue for accurate position-dependent response prediction. Additionally, the built-in Calculator is now updated with subwoofer modeling, allowing you to generate subwoofer delay values for electronic subwoofer array steering (EDS).

Mechanical Validation of single and dual-point array suspensions can now include weight limit calculations in real time. Array statistics are calculated that include array size, depth and weight and array design factors are calculated, that you can use to design arrays that meet local safety and regulation limits. Safety warning messages can also be provided when an unsafe configuration is selected.

Updates found in the new Line Array Calculator 3 include: a completely redesigned UI that’s both more intuitive and combined with an unlimited number of planes; more virtual measurement probes; frequency response averaging of multiple virtual measurements; and a brand-new subwoofer prediction mode. Multiple subwoofer clusters can now be entered into the display window and the software will predict broadband polar response of the entire array. With Line Array Calculator 3, system designers can now make more informed decisions about how subwoofer arrays should be placed in venues and aid in the optimization of these arrays for their best possible performance.



  • Acoustic prediction of JBL VTX Line Array Systems as well as flow and ground stacked subwoofer arrays
  • Support for 8 virtual measurement probes for predicting the frequency response of an array
  • New subwoofer prediction mode for acoustic prediction of ground stacked arrays with the ability to generate delay values for Electronic Delay Steering (EDS)
  • Built-in array optimization tools including the new JBL Array Size Compensation (ASC) filter
  • Full integration with JBL’s Performance Manager control software
  • Mechanical validation of arrays in real-time for single and dual-point suspension modes
  • Array statistics including array size, depth, weight and design factor
  • 3D DXF Export support
  • EASE GLL configuration export support


JBL Array Link is a mobile companion app that works in conjunction with JBL’s latest LAC-III software to assist technicians deploying JBL VTX Series line array systems. Array Link uses a QR code system to transfer all array mechanical information from the main LAC-III application to a mobile phone – this transfer is done directly and in real time without the need of internet connection. All relevant rigging information and options are presented in an easy-to-understand layout.

The application is compatible with iOS® and Android and can be obtained from the respective App Stores.

System Requirements

Supported Operating Systems:

  • 64-bit versions of Windows 7, Windows 8.1 or Windows 10

Minimum Performance Guidelines:

  • CPU: 64 bit dual core @ 2.0GHz or better
  • Memory: 2GB

LAC3 supported devices:

  • VTX A12
  • VTX A12W
  • VTX A8
  • VTX B18
  • VTX V25-II / VTX V25-II-CS
  • VTX V20
  • VTX S25
  • VTX S28
  • VTX G28

New in 3.4.0:

New Features:

  • Compatibility support with ArrayLink Version V1.2 and Performance Manager V2.6.5
  • Venue Page Improvements including the ability to export and import venue geometry
  • Improvements in Ground Stack Subwoofer Mode
  • New “Suspension Mode” and “Suspension Point” option added to the configuration page
  • New settings panel in Mapping mode
  • Automatic Circuit Grouping
  • Added Amplification Mode selection for V20, S25 and S28
  • Line Array Control Panel Improvements including the new Master Reset Button
  • Improvements in Ground Stack Array Mode
  • Improvements in SPL Mapping page

Bug Fixes:
  • User preferences (like Unit selection) are preserved after installing a new version of LAC.
  • A12W can now be placed above A12 if needed.
  • Circuit grouping colors have been added back to Ground Stack Array mode.
  • Addressed several issues related to the QR code export for ArrayLink. Depending on the Windows localization settings, LAC would sometimes send the incorrect information to ArrayLink.
  • The VTX V20 DF can now be used as a standalone pull-back frame for V25-II systems.
  • Pull-back has been removed for compression style systems (V20 and V25-II-CS) since array geometry is not quarantined when a pull-back is used.
  • Updated V20 Bi-Amp directivity and frequency response data.
  • The cabinet connected to the array frame or an adapter frame now shows AF (or DF) in the angle box.
  • A new drop-down menu is available for the A12 in the configuration page to allow for reversing the Array Frame independent from the extension bar.
  • The LAC default (start) configuration has been adjusted to include six cabinets.




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  Version Language Size Uploaded
Line Array Calculator III
version 3.4.0, updated: Jul 27, 2020
3.4.0     12.5 MB Jul 27, 2020

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