Line Array Calculator III v3.6.0.147 (Windows)

Note: this is an old version. The current version is: Line Array Calculator III v3.9.0 (Windows). ×

Last Updated: sept. 15, 2023


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 B28
  • VTX V25-II / VTX V25-II-CS
  • VTX V20
  • VTX S25
  • VTX S28
  • VTX G28

New in 3.6.0:

New Features and Improvements:

Added support for the following products:

  • VTX B28, VTX B28 SB, VTX B28 GND, VTX B28 VT, VTX A12 BP and the VTX V20 BP

SPL Over Distance:

  • A new SPL visualization method has been added to LAC called SPL Over Distance. The new graph is a variation of the existing SPL attenuation function but displayed outside the venue view and into a dedicated graph. The new mapping method can display up to two individual frequencies or the average between two selected frequencies. SPL over distance is available in Mapping mode and can be switched on via the “Mapping Type” drop-down menu.

Electronic Delay Steering for Suspended Subwoofer Arrays:

  • LAC-3 has incorporated mapping and optimization for ground-stacked subwoofer arrays for some time now. This version of LAC-3 adds delay calculation and optimization for Suspended Subwoofer arrays. The delay calculator includes the ability to specify an opening angle and the direction of the subwoofer beam. Delays can be generated for symmetric coverage, and options to steer the array up or down are available.
  • Delays generated by LAC-3 can be directly imported into Performance Manager version 2.8.0 to be uploaded to I-Tech HD amplifiers.

QR Code Generation for Ground-Stacked Arrays:

  • LAC-3 can now generate a QR code for ground-stacked arrays. Similar to suspended arrays, the QR code includes information related to speaker angles, accessory selection, and positioning. Traditional and mixed arrays are supported.

Center-of-Gravity Calculations Based on Cable Weight:

  • This version of LAC includes improved center-of-gravity calculations that take into consideration the cable weight added by the user. This new function is especially useful in single-point configurations where cable weight can significantly impact array aiming. Once a value is entered, LAC performs the calculations in real-time, and a new arrow displayed on the array drawing indicates where the cable weight is applied. All array frames except for Suspension Bars support this new feature.

Updated “Project Details” Information and Structure:

  • The “Project Details” fields are now auto-filled to simplify integration with the Array Link mobile app. The Project Name is now the same as the file name, and the date is set based on the computer’s calendar information. This feature can be switched off from the Application Options panel to enter the information manually.

General Improvements:
  • A new “Master Bypass” button is now available in the LACP panel. The new function bypasses all filters across all circuits, and it’s especially useful when comparing LACP settings.
  • The panel under the Venue graph in Mapping mode can now be minimized (collapsed) to enlarge the venue view on smaller screen sizes.

Bug Fixes:
  • Fixed several UI issues presented on Surface Pro computers with high-resolution screens.

Stay informed of JBL software releases and updates

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