Understanding the Different Suspension Systems Used for Main PA, Side PA and Relay Towers
Line array loudspeakers are among the heaviest suspended components found on a modern concert stage.
Unlike lighting fixtures or LED panels, a line array does more than produce sound. Its position directly affects audience coverage, sound pressure distribution and listening consistency across the venue.
For this reason, engineers do not simply hang every line array from the nearest structure.
Instead, each array is suspended from a structural system specifically designed for its location, loading requirements and acoustic function.
During the construction of the 2026 Guangzhou Pearl Beer Festival Music Festival, three different line array suspension methods were observed:
The main PA system was suspended from cantilever beams beneath the roof apron.
The side PA systems were suspended from truss beams mounted on independent Ringlock structures.
Relay speaker systems were suspended from approximately 20-metre-high relay towers positioned in the middle of the stadium.
These observations reveal an important engineering principle:
The safest suspension point is not always the highest one—it is the structure specifically designed to carry the required load while delivering the correct acoustic coverage.
The overall sound system layout is discussed in How Is a Stadium Concert Sound System Distributed?, while this article focuses on the structural engineering behind safely suspending those systems.
Engineering Observation
Three independent suspension systems were used during this project.
Line Array Location
Supporting Structure
Main PA
Cantilever beam beneath the roof apron
Stage side PA
Truss beam fixed to Ringlock structure
Relay PA
Independent relay tower
Although all three systems supported line arrays, each served a different engineering and acoustic purpose.
Why Are Line Arrays Suspended Instead of Placed on the Ground?
Large line arrays are suspended for several reasons.
Suspending the speakers:
Improves audience coverage.
Prevents sound from being blocked by spectators.
Creates better vertical dispersion.
Reduces reflections from the stage floor.
Allows sound to project over long distances.
The suspension height is therefore determined by acoustic performance as well as structural safety.
Main PA Arrays Are Suspended from the Roof Apron
The primary line arrays were positioned at the front of the main stage.
Instead of hanging directly from the roof truss, they were suspended from cantilever beams extending beneath the roof apron.
This arrangement offers several engineering advantages.
Better Audience Coverage
Positioning the arrays at the front edge of the stage reduces obstruction from:
The roof structure.
Lighting equipment.
The LED backdrop.
This allows sound to project directly into the audience.
Independent Structural Support
The cantilever beam is specifically designed to transfer the concentrated speaker load into the main roof structure.
This creates a dedicated load path rather than distributing speaker loads across multiple roof members.
Easier Rigging and Maintenance
Suspending the speakers from the apron area also provides convenient access for:
The structural system supporting it must therefore be designed to resist:
Vertical dead load.
Dynamic loading during lifting.
Wind forces.
Vibration during operation.
For this reason, professional suspension systems typically include:
Certified rigging hardware.
Chain motors or manual hoists.
Steel suspension points.
Independent safety steel cables.
Structural verification before lifting.
The loudspeaker itself is only one part of the suspension system.
The supporting structure is equally important.
Different Locations Require Different Suspension Methods
The suspension systems observed during this project can be summarised as follows.
Speaker Location
Supporting Structure
Engineering Purpose
Main PA
Roof apron cantilever beam
Front audience coverage
Stage side PA
Truss beam on Ringlock tower
Side coverage and independent support
Relay PA
20-metre relay tower
Long-distance sound reinforcement
Each system was selected according to both structural capacity and acoustic performance.
Engineering Lessons from This Project
Several important engineering principles can be drawn from these observations.
1. Suspension Method Depends on Function
Not every speaker should be hung from the main roof.
Different locations require different structural solutions.
2. Load Paths Must Be Clearly Defined
Every suspended line array transfers its weight through a dedicated structural path.
Understanding that load path is essential for safe temporary structure design.
3. Acoustic Design and Structural Design Must Work Together
The best structural position is not necessarily the best acoustic position.
Successful concert engineering balances both disciplines simultaneously.
4. Independent Structures Improve Flexibility
Using Ringlock towers and relay towers allows engineers to optimise sound coverage without overloading the main stage roof.
This modular approach also simplifies installation and adapts more easily to different venue layouts.
Conclusion
Large concert line arrays are not suspended from a single universal structure.
Instead, each system is supported by a structural solution specifically designed for its function.
During the Guangzhou Pearl Beer Festival Music Festival project, three suspension methods were observed.
The main PA arrays were suspended from cantilever beams beneath the roof apron to provide direct front coverage.
The side arrays were hung from truss beams mounted on independent Ringlock towers, creating flexible and structurally independent support.
The relay arrays were installed on approximately 20-metre-high relay towers positioned in the centre of the stadium to extend sound coverage to distant audience areas.
Together, these systems demonstrate one of the fundamental principles of concert engineering:
Safe line array suspension is achieved not by using the same structure everywhere, but by matching each loudspeaker system to the structure best suited to its location, load and acoustic purpose.
The DragonStage 11x6x7m Covered Concert Roof Truss System combines an 11m-wide × 6m-deep × 7m-high main stage roof with two 2m side PA speaker wings.
The illustrated configuration features a pitched aluminum roof framework with a blue roof canopy, four main support towers, two independent speaker towers, and a matching modular stage platform with guardrails and dual stair access.
Designed for concerts, festivals, live performances, community events, and temporary outdoor productions requiring a coordinated stage roof and separate speaker-support positions.
The DragonStage 10x5x7m Aluminum Pitched Roof Truss System is a modular concert-stage structure featuring a 10m-wide × 5m-deep × 7m-high main roof frame with 2m side speaker wings on both sides.
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Designed for stadium-scale ceremonies, festivals, cultural performances and large outdoor event productions, the system integrates extensive scaffold support zones, heavy aluminum roof trusses, custom roof connectors, tensioning components and a large roof canopy.
The drawing identifies a nominal 32m × 24m × 18m configuration, with the overall height shown at approximately 18.21m.
A complete professional event sound package combining 16 dual-12-inch passive line array speakers, 10 dual-18-inch subwoofers, 6 stage monitors, dedicated Class-D power amplifiers, dual 4-in/8-out DSP processors, power management, wireless microphones, rigging frames, flight cases, amplifier racks and cabling.
This system is designed for concerts, live performances, festivals, touring productions and other professional event sound applications where the customer needs a coordinated PA package rather than individual speakers.
For other professional audio systems, see Stage Sound.
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The system uses CS389×389mm and CS289×289mm aluminum spigot truss, sleeve block assemblies, BA05 manual hoists, tower bases, outriggers, and a PVC roof canopy. The side wings extend the configuration for additional event-production arrangements, subject to the final equipment layout and verified loading requirements.
Designed for concerts, music festivals, touring productions, and temporary entertainment stages, this system can be supplied with matching modular stage platforms and accessories.
Custom Star Shape Truss Aluminum for Wedding Decoration Art Design
Pentagram，five-pointed star
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The customized star geometry provides an alternative to conventional square, rectangular, or circular event truss structures.
The DragonStage 9x6m Bolt Truss Gantry System is a modular event-support structure featuring two vertical truss towers, a horizontal bolt-connected truss beam, tower-head assemblies, base plates, and diagonal outrigger bracing.
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The DragonStage 36x18x12m Large Concert Stage Roof Truss System is a large-format modular event structure featuring a multi-tower truss support system, an elevated overhead truss framework, and a modular stage platform with guardrails and stair access.
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The DragonStage 6.72x4.89m modular event stage combines a 0.6m-high red stage platform with a 7.7m-wide, 4.4m-high rear box truss gantry. The open-top configuration provides a raised performance area and a separate overhead truss frame for event backdrop and production applications. Suitable for concerts, school performances, ceremonies, and indoor events, with final accessories and rigging requirements confirmed according to the project.
The DragonStage 25x10m Ringlock Grandstand is a large modular spectator-seating system designed for temporary sports events, school competitions, festivals, public performances, and other audience gatherings. Measuring 25m wide × 10m deep, the illustrated configuration features tiered seating, two access aisles, and three-sided guardrails. The specified main height is 2.5m, with an overall height of 3.5m. The modular Ringlock system can be configured according to the required seating layout, access arrangement, and project conditions.
A heavy duty iron adjustable clamp specifically designed for use in clear span marquees using grooved aluminium kader style beams. It has M10, M12 and M14 tapped mounting points.
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Section:Square200x200mm inclined tube: 12x2.0mm Main tube: 30x2.0mm Length:0.5/1/2/2.5m Braces: 20x2.0mm
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This box can be used to create a stable structure for your display or party. You can use this box to create a corner truss cube. It can be used for exhibitions, retail, and party displays. The box has a 400x400mm or 389x389mm square opening. The box has six ways to connect.
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Aluminum Spigot Truss Aluminum Base Plate with Handles 300mm 400mm 500mm 600mm 800mm with half conical and pins clips.
The DragonStage Aluminum Spigot Truss Base Plate with Handles is available in five square sizes from 300×300mm to 800×800mm, all using an 8mm-thick aluminum plate. Each configuration can be supplied with compatible half conical connectors, connector pins and R-clips for spigot truss installation. Integrated handles make the plates more practical to carry and position during repeated event setup and teardown.
this is 100x100x3mm base plate for f14 truss mini, with 4 half connectors and pins clips.
The DragonStage F14 Mini Truss Square Base Plate is a compact 100 × 100 × 3mm base plate supplied with 4 half conical connectors, connector pins and R-clips for compatible F14 mini truss systems. It is designed as a small mounting and connection accessory for exhibition, display, DJ, decorative and lightweight mini-truss applications.
Section:Square400x500mm Inclined tube: 25x2.0mm Main tube:50x3.0mm Braces:50x2.0mm Material: Aluminum 6061-T6
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Section:Square500x500mm Inclined tube: 25x2.0mm Main tube:50x3.0mm Braces:50x2.0mm Material: Aluminum 6061-T6 This heavy-duty 500x500mm bolt aluminum square truss is the ultimate foundation for outdoor concert stages and large-scale events. Engineered for maximum structural stability, this aluminum truss system provides the high-load capacity needed to support massive lighting rigs and heavy audio arrays safely in any environment.
Section:Square400x400mm Inclined tube: 25x2.0mm Main tube:50x3.0mm Braces:50x2.0mm Material: Aluminum 6061-T6
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Park Aluminum Portable Square Stage 8.54x6.1m 28x20ft Height: 0.8-1m
The DragonStage 8.54x6.1m Aluminum Park & Community Event Stage is a 28x20ft brace-supported modular platform built from 35 standard 4x4ft stage decks. The complete configuration includes 18mm anti-slip plywood decking, adjustable support stands, three-side guardrails, a 4-step stair, and black stage skirting, making it suitable for community concerts, park events, ceremonies, public performances, school activities, and temporary outdoor stages.
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Aluminum Mini Modular Stage Panel Flooring Systems 2.44x2.44m 8x8ft Height 0.6-1m with 1 stair.
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Base plate only for the U-Frame 50. LED cans and moving heads can be installed freeriding in the room. In combination with the optional wheels the U-Frame Dolly will be an indispensable element on stages and show acts.
U-frame Truss And Dolly, it is custom U torm trusses (660 × 500 × 50mm) for 4 (4 utorm trusses+ top bar+ dolly) and 5 (4 utorm trusses+ top bar+ dolly) Robots in black color.
the dolly is made of 1.2x0.6m aluminum plate, thickness 8mm and 4 casters.
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The DragonStage 3.0x1.22m Compact Aluminum Stage Transition Ramp provides a short, direct access route between ground level and temporary event stages. With an overall length of approximately 3.0m / 9.84ftand a width of approximately 1.22m / 4ft, the ramp uses modular aluminum stage components and includes 1m / 3.28ft high guardrailson both sides.
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