Overview

The DSP in the LA Active Line Array Series currently provides a one‑button voicing solution for arrays of up to six loudspeakers. QSC recognizes the need for a recommended voicing approach for larger arrays. While upcoming LA Series firmware will add native support for extended arrays (seven or more loudspeakers), a comparable result can be achieved today using the existing system architecture. The Ar‑Q™ feature enables users to manually enter key array parameters (Box Count, Box Number, and Total Splay) providing a reliable starting point for external system tuning of arrays with seven or more loudspeakers.

What is Ar-Q?

As the size and total vertical coverage of an array is altered, the resulting change in low frequency (LF) energy output is not the same as the change in high-frequency (HF) output. To maintain consistent balance between LF and HF, array equalization filters are used. These filters display varying amplitude and frequency, and Ar-Q contains the recommended proprietary QSC filters for each specific deployment.

A flat array promotes high-frequency coupling, resulting in natural acoustic summing and reducing the amount of HF compensation required to match the LF and MF summing	An arcuate array reduces HF coupling because the waveguides are angled farther apart, requiring more HF compensation to balance the LF and MF summing.

Deployment

When deploying arrays of seven or more L‑Class loudspeakers, system voicing must be tailored by the system engineer, as no QSC DSP voicing is currently provided for extended arrays. The manual Ar‑Q settings described below offer a practical and efficient starting point, enabling users to achieve strong baseline performance with minimal setup effort.

Preparation

• Ensure that all loudspeakers are on the latest firmware for optimal system operation. You can check the current firmware version by installing the latest version of L Class Firmware Updater.
• Ensure that System Navigator is closed and not communicating with the L Class array. If System Navigator was previously used with these loudspeakers, it is best to complete a factory reset on each loudspeaker by holding down the Menu and ID buttons on the Rear User Interface simultaneously for 3 seconds.
• Review current draw specifications listed in the L Class User Manual.
• Review the General Rules of Suspension, Shock Loading, and Maximum Suspended Load sections of the L Class User Manual.

Procedure

1. Power on the L‑Class array using the AC loop‑through connectors on the rear panel of each loudspeaker.
2. Once all loudspeakers have fully booted, use the rotary encoder on the Rear User Interface (RUI) to set the GAIN fader to +0 dB.
3. Press the Menu button on the RUI. Use the rotary encoder to scroll to Ar‑Q, then press the encoder to select.
4. In the Array Equalization menu, configure the following baseline Ar‑Q parameters:
   1. Box Count: 6
   2. Box Number: 1-6 (for first 6 loudspeakers)
   3. Total Splay: 27 degrees
      1. This starting point is based on nominal inter‑box splay angles of 1.5° / 1.5° / 6° / 6° / 12° and is used for both LA108 and LA112 arrays when deploying seven or more loudspeakers.
   4. Loudspeakers 7+ should all be entered as Box Count: 6, Box Number: 6, and Total Splay: 27 degrees as directed above.
5. Select Confirm to apply the Ar‑Q values.
6.  Press the Menu button to return to the Main Menu. At this stage, verify all other loudspeaker parameters as required, including:
   1. High‑Pass Filter (HPF)
   2. Delay
   3. HF Shading
   4. Sensitivity
7.  Press the Menu button again to return to the Home Page. 
8.  Repeat Steps 2 through 7 for each loudspeaker in the array.
9.  Apply additional EQ as required based on loudspeaker model and total box count. The following EQ recommendations apply globally to all loudspeakers in the array once the specified total box count is reached and are not applied to only sections of the array. These filters may be implemented using the mixing console or external signal processing.
   1. LA108 arrays
      1. 7 boxes: 
         1. Apply a PEQ filter at 600 Hz, –1.25 dB, Q = 2.67
      2. 8–12 boxes: 
         1. Apply a PEQ filter at 600 Hz, –1.5 dB, Q = 2.63
         2. Apply a second PEQ filter at 6 kHz, –1.0 dB, Q = 2.71
   2. LA112 arrays
      1. 7–9 boxes: 
         1. No additional EQ required
   3. 10–12 boxes: 
      1. Apply a PEQ filter at 3 kHz, –2.0 dB, Q = 2.56

Outcome

Although a one‑button DSP voicing solution is not currently available for arrays of seven or more LA Series loudspeakers, the procedures outlined in this document provide the closest achievable match within the existing system architecture. By applying these Ar‑Q settings and model‑specific EQ recommendations, users can establish a strong baseline that delivers optimal acoustic performance and supports efficient final system tuning.