Emergency Broadcast System Construction and Implementation Based on OpenAudio HOLOWHAS Multi-Zone Amplifiers

Based on OpenAudio HOLOWHAS Multi-Zone Amplifiers

Executive Summary

Emergency broadcasting is a mission-critical audio system responsible for delivering mandatory instructions and alerts during fires, earthquakes, security incidents, gas leaks, and other life-safety events. Unlike background audio or commercial PA systems, emergency broadcast systems must guarantee:

• Immediate response
• Absolute audio priority
• Full-area or zone-specific coverage
• Offline survivability
• Hardware-level reliability

OpenAudio HOLOWHAS multi-zone amplifiers provide an ideal hardware foundation for building professional emergency broadcast systems. By combining OpenAudio’s unified control architecture with HOLOWHAS’s multi-stream, multi-zone amplifier design and hardware-level source priority mechanisms, integrators can construct emergency broadcast systems that remain operational even when networks, controllers, or automation platforms fail.

This article provides a complete technical blueprint for designing, implementing, and maintaining emergency broadcast systems based on OpenAudio HOLOWHAS multi-zone amplifiers.

1. Design Philosophy: Hardware-First Emergency Execution

Most failures in emergency broadcast systems originate from excessive dependence on centralized software platforms.

The OpenAudio + HOLOWHAS approach follows a hardware-first execution philosophy:

• OpenAudio handles scheduling, logic, and integration
• HOLOWHAS amplifiers execute emergency audio locally at hardware level

Even if the control layer becomes unstable, HOLOWHAS amplifiers retain the ability to trigger emergency audio locally and enforce priority rules.

This architecture ensures emergency playback capability is never purely software-dependent.

2. Key Capabilities of HOLOWHAS for Emergency Broadcasting

HOLOWHAS multi-zone amplifiers offer several native features critical to emergency use:

2.1 Multi-Zone Independent Amplification

• Each zone has its own amplifier channel
• Zones can operate independently or in groups
• Emergency audio can target:
  • Single zone
  • Multiple zones
  • Entire building

2.2 Multi-Source Audio Inputs

HOLOWHAS supports multiple audio sources:

• AirPlay 2
• Spotify Connect
• DLNA / UPnP
• Bluetooth
• Network streams
• Local USB storage

This allows emergency audio to originate from:

• Local stored files
• Network streams
• Real-time microphone input

2.3 Hardware-Level Priority Override

Emergency sources can be configured as highest priority inside HOLOWHAS firmware.

When emergency mode activates:

• All regular audio sources are forcibly muted
• Emergency audio takes exclusive control
• User volume settings are ignored

This happens inside the amplifier hardware, not in software.

2.4 Local Emergency Audio Storage

Emergency audio files can be stored on:

• HOLOWHAS internal storage
• USB flash drive

This enables offline emergency playback even if:

• Network is down
• Control server is offline

2.5 Preset Emergency Volume

HOLOWHAS can automatically switch to a predefined emergency volume level ensuring audibility even if zones were previously muted.

3. Role of OpenAudio Control Architecture

OpenAudio serves as the orchestration layer that:

• Receives triggers
• Applies logic
• Dispatches commands

It communicates with HOLOWHAS using standard IP-based control interfaces.

OpenAudio enables:

• External system integration
• Rule-based automation
• Remote management
• Monitoring and logging

However, OpenAudio does not replace HOLOWHAS emergency capability; it enhances it.

4. Three-Layer System Architecture

The system is logically divided into three layers:

4.1 Trigger Layer

Sources that initiate emergency events:

• Physical emergency buttons
• Fire alarm panels
• Smoke detectors
• Gas sensors
• Security systems
• Weather alert platforms
• Manual commands from staff

4.2 Control & Scheduling Layer

• OpenAudio
• Optional integration with:
  • Home Assistant
  • Building Management Systems (BMS)
  • Security platforms

4.3 Execution Layer

• HOLOWHAS multi-zone amplifiers
• Loudspeakers per zone

HOLOWHAS is always the final execution authority.

5. Trigger Methods

5.1 Local Physical Trigger

Emergency button wired to:

• IO module
• Controller
• Direct trigger interface

Activates emergency mode instantly.

5.2 Sensor-Based Trigger

• Smoke
• Temperature
• Gas
• Water leakage

Sensors report to OpenAudio or directly to HOLOWHAS trigger inputs.

5.3 External System API Trigger

Fire alarm system sends HTTP/MQTT command to OpenAudio.

5.4 Manual Remote Trigger

Authorized operator triggers emergency from dashboard or mobile interface.

6. Emergency Audio Flow

1. Trigger occurs
2. OpenAudio sends emergency command
3. HOLOWHAS enters emergency mode
4. Regular audio is cut
5. Emergency audio starts
6. Preset volume enforced

If OpenAudio is offline:

• Local trigger activates HOLOWHAS directly
• USB emergency audio plays

7. Zone-Level Emergency Broadcasting

HOLOWHAS supports:

• Global emergency broadcast
• Floor-level emergency
• Room-level emergency

Examples:

• Fire in garage → Garage zone only
• Intruder in building → Entire building
• Gas leak in kitchen → Kitchen zone only

This prevents unnecessary panic.

8. Three Implementation Models

8.1 Basic Local Standalone System

Target: Homes, small shops, cafes

Components:

• HOLOWHAS amplifier
• USB emergency audio
• Emergency button

Features:

• No network required
• Hardware-only execution

Workflow:

Button → HOLOWHAS → Emergency Audio

8.2 Network-Integrated System

Target: Offices, schools, hotels

Components:

• HOLOWHAS
• OpenAudio controller
• Sensors
• Network connection

Features:

• Automatic triggers
• Zone selection
• Remote monitoring

8.3 Professional Redundant System

Target: Hospitals, campuses, commercial complexes

Additional components:

• UPS for HOLOWHAS
• Redundant OpenAudio controllers
• Real-time microphone

Features:

• Live voice announcements
• System health monitoring
• Event logging

9. Reliability Design

9.1 Dual Priority Protection

• OpenAudio software priority
• HOLOWHAS hardware priority

9.2 Offline Survival

• Local USB audio
• Local triggers

9.3 Power Backup

• UPS keeps amplifier alive

9.4 Sub-Second Command Response

• IP command < 300 ms
• Audio start typically < 2 seconds

10. Commissioning Checklist

• Verify emergency audio audibility
• Test zone mapping
• Test offline playback
• Test power loss recovery
• Verify priority override
• Document configuration

11. Application Scenarios

Hospitals

• Fire evacuation
• Code blue
• Hazard warnings

Hotels

• Fire
• Weather alerts
• Floor-specific evacuation

Bars & Clubs

• Fire
• Crowd control

Schools

• Lockdown
• Fire drills
• Evacuation

12. Why HOLOWHAS Is Ideal for Emergency Broadcasting

• Hardware-level execution
• Multi-zone native architecture
• Multi-source input flexibility
• Offline survivability
• Scalable

HOLOWHAS transforms emergency broadcasting from a fragile software feature into a robust hardware-backed safety system.