Application design · commercial
Offices & commercial buildings PA system
Background music, floor paging and evacuation in a building that has to feel calm every day and work under pressure once.
Reference application image. Client names are withheld; the equipment schedule is confirmed per project.
Zoning: Per floor / riser · Coverage: ≤15 m · Emergency level: +15 dB
The design brief
What the space has to do
A commercial building has two very different audio lives. On a normal day, the lobby, lifts, corridors and retail areas need quiet background music and occasional paging. On the day of an incident, the same building needs a clear evacuation message that overrides everything. The system has to do both without a second network.
The design follows the building’s vertical zoning: floors, risers and fire compartments. The lobby, retail podium, office floors, car park and plant areas are separate zones. The head end is in the fire control room, and the fire interface has priority over all other sources.
Design checks
| Parameter | Value | Note |
|---|---|---|
| Zoning | Per floor / riser | follow the fire compartments |
| Coverage | ≤15 m | to the nearest loudspeaker in a fire compartment |
| Emergency level | +15 dB | above the local ambient noise |
| Control | Limited range | tenant adjustment within a defined range |
Interface & responsibility
What has to be agreed before installation
The acoustic design is only half the job. These interfaces decide whether the system can be installed, tested and accepted.
| Interface | Typical arrangement | Who provides | Confirm |
|---|---|---|---|
| Fire alarm interface | Hard-wired trigger per zone or group | Fire contractor / SONTRA interface design | Cause-and-effect matrix |
| Paging console | Desktop console or IP paging station | SONTRA supply / local installer | Zone access and priority |
| Network / IT | Dedicated VLAN, QoS, multicast | Client IT / integrator | Network sign-off |
| Loudspeaker circuits | 100V line per zone / riser | Local contractor / SONTRA schedule | Impedance and tap test |
What usually goes wrong
Three physical problems, not three products
Multiple tenants
Different floors may want different music or no music at all. The zoning and the control access have to reflect the tenancy.
Fire compartments
The loudspeaker circuits must follow the fire strategy. A riser crossing several floors cannot be treated as one audio zone.
Quiet daily operation
The system must be unobtrusive at low levels. Coverage and tap setting matter more than power.
The design response
What we change in the system
Vertical zoning
Lobby, retail, office floors, car park and plant are separate zones, with riser-based loudspeaker circuits.
Tenant control
Local volume controls or software permissions let tenants adjust their own floor within a limited range.
Fire override
The fire alarm overrides the music and paging. The evacuation message follows the fire strategy and the compartment layout.
Central head end
The head end and the fire interface are in the control room. Distributed IP amplifiers can reduce long 100V runs in a tall building.
Zone schedule
A starting point for the zoning
The final zone list follows the building’s operation and fire compartments. This is the typical structure.
| Zone | Need | Typical kit |
|---|---|---|
| Lobby and reception | Background music, paging | Ceiling loudspeakers, low taps |
| Office floors | Tenant music and paging | Ceiling loudspeakers, per-floor control |
| Retail podium | Music and promotional announcements | Ceiling loudspeakers, separate zones |
| Car park and plant | Paging and evacuation | Horn or wall loudspeakers, higher taps |
Equipment families
The blocks used in this design
These are the families that usually make up the system. The final model list follows the zone schedule and the certification route.
PA line · coreBroadcast control & amplifiers
Broadcast hosts, zone controllers, mixer amplifiers and IP amplifiers for background music, paging and emergency override — specified as one signal chain.
PA line · outputCeiling, horn, column & wall loudspeakers
Ceiling, horn, column, wall and landscape loudspeakers for corridors, halls, factories, stations and outdoor areas — selected by coverage and environment, not by wattage alone.
PA line · everydayBackground music systems
Music sources, players, zone volume control and loudspeaker selection for hotels, retail, restaurants, offices and public areas — with the paging and fire override designed in from the start.
PA line · life safetyVoice alarm & fire interface
Voice-alarm control, evacuation messages, fire-alarm interfaces and monitored loudspeaker circuits — specified to the standard the project actually has to meet.
Related applications
Adjacent spaces, different rules
Hotel public areas
Lobby, restaurants, corridors, spa and pool — one background-music system with the ballroom and the fire alarm on speaking terms.
View application design
Existing building retrofit
New paging and evacuation in a building that cannot be opened up, closed down or filled with new cable.
View application design
Schools & campuses
One bell, one paging system and one evacuation path across classrooms, corridors, playgrounds and canteens.
View application designQuestions
Frequently asked questions
The questions that usually decide the scope: loudspeaker count, amplifier size, fire interface, certification and who installs the system. If your question is not here, send it with the building data.
Ask an application engineerCan each tenant have its own music?
Yes, within the system’s zoning and source capacity. The tenant can select a source and adjust the level within a limited range. The head end keeps overall control and the fire override.
Does the system need a separate fire-rated cable?
The cable requirement comes from the fire strategy and the local code. Voice-alarm circuits often require fire-rated cable and specific routing. The electrical consultant confirms the requirement before the cable is specified.
Can we add paging to an existing BGM system?
Often yes, if the amplifier has a paging input and the zoning is suitable. The fire interface and the priority table must be checked. A retrofit survey is the first step.
How do you keep the lobby music quiet but even?
Use more loudspeakers at lower taps rather than fewer loudspeakers at higher taps. The coverage overlaps at a low level, so the music is even and unobtrusive. The EQ is set during commissioning.
Next step
Send the room data once
A sketch, a room schedule or a drawing link is enough to start. This application can be supplied as a complete package: own-factory equipment, full system configuration and one combined proposal covering the adjacent rooms or systems.
- Room sizes, ceiling height and finishes
- Seat, table or zone count
- Fire interface and applicable standard
- Any ODM / OEM or private-label requirement
Project inquiry
Discuss Offices & commercial buildings
Send the room or building data once. We return one combined proposal covering PA, conference, ballroom and AV, with the equipment schedule, interface list and the questions that still need an answer. ODM and OEM inquiries are welcome. Drawings are welcome but not required.