How Fill Speakers Improve Audience Coverage in Cultural Venues

The complete stage technology project was designed and implemented by UAB “Scenos Techninis Servisas” (STS), including the integration of a full L-Acoustics professional audio system.

System Design Approach

The objective was to deliver:

• Even SPL distribution across the audience area
• High speech intelligibility for conferences and civic events
• Full-bandwidth musical performance for concerts and touring productions
• Operational flexibility for multiple event formats

“Our design scope was to deliver consistent coverage and tonal balance to every seat in the hall, while ensuring the flexibility required for a wide range of event formats,” — Julius Gružinskas, Head of Design Department, Scenos Techninis Servisas (STS).

Given the fan-shaped audience layout, shallow first rows, and extended seating depth, particular attention was placed on front-to-back consistency and near-field clarity.

Installed L-Acoustics System

Main Front PA
A15i Focus – 4
A15i Wide – 2
KS21i – 4

The combination of A15i Focus and Wide enclosures enables precise horizontal coverage control, adapting to the hall geometry while maintaining tonal consistency throughout the audience area. The KS21i subwoofers provide extended low-frequency response and controlled LF performance suitable for amplified music and large-scale events.

Distributed Fill System
X8i – 4 (Front Fill)
X8 – 4 (Delays)

The distributed fill system ensures a consistent coverage of front and rear seating zones where it is hard to cover only with the main PA system.

 Amplification & Control
The LA7.16i platform provides centralized amplification, system management, and signal processing within a streamlined installation footprint.

Stage Monitoring
The six X15HiQ coaxial stage monitors deliver high output and clarity for performers across concerts, theatre productions, and ceremonial events.

System Design and Coverage Optimization

System design in Soundvision was  used to validate system behavior and optimize interaction between the A15i main arrays and the distributed fill system.

Main System Performance (Without Fills)
Simulation of the A15i + KS21i configuration demonstrates:

• Controlled horizontal dispersion aligned with the fan-shaped audience geometry
• Stable mid- and rear-zone coverage
• Defined vertical aiming toward deeper seating areas

However, modeling confirms a natural energy reduction in the near-field seating area when operating without front fills. This is typical in multipurpose cultural venues where first rows are positioned below the primary mechanical aiming axis of the main arrays.

System Performance with Front and Rear Fills Activated
When the X8i front fills and X8 rear fills are engaged, Soundvision modeling shows a measurable improvement in overall uniformity. Observed benefits include:

• Reduced front-to-back SPL gradient
• Enhanced energy distribution in the first seating rows
• Improved tonal consistency across lateral seating zones
• More stable intelligibility conditions for speech-driven events

Practical Role of Fill Systems in Cultural Venues

In venues such as Kėdainiai Culture Centre, programming alternates between speech-intensive events and amplified performances. This requires a system capable of delivering:

• Controlled SPL variance across all seating areas
• Intelligibility at moderate operating levels
• Listening comfort for extended events

The fill system in this installation is not supplementary—it is integral to achieving professional-grade acoustic uniformity within the architectural constraints of the hall.

Front fills provide direct sound energy to near-field seating without increasing overall system level. Rear fills support tonal consistency and level stability in deeper seating zones. Together with the A15i main arrays, the distributed system architecture ensures predictable and scalable performance across event formats.

Operational Impact

The upgraded audio infrastructure supports the Centre’s diverse programming requirements while aligning with contemporary performance standards.
“The new sound system has significantly improved clarity and audience experience. It allows us to host a broader range of events with confidence in consistent sound quality,” — Daiva Urbonienė, Director of Kėdainiai Culture Centre

 A Regional Cultural Reference Venue

The renovation of Kėdainiai Culture Centre demonstrates how heritage venues can integrate modern professional sound technology without compromising architectural identity.

The L-Acoustics A15i platform, combined with distributed fill architecture and centralized amplification, provides scalability, coverage precision, and long-term reliability—positioning the venue as a key cultural reference point within the region.

Photos and Soundvision visualisations credit: Scenos Techninis Servisas