In just a few years, Ajax Systems has established itself as one of Europe's leading wireless alarm references. The catalog now includes over two hundred devices, which is good news for covering needs and bad news for anyone who has to choose. This guide follows the order in which decisions are actually made on the ground.
1. The Hub first, always
The Hub is the brain of the system. It receives signals from all devices, decides whether to trigger the alarm, and transmits to your smartphone as well as to a central monitoring station. Everything else stems from this, and it's the only component that's difficult to replace once the installation is in place.
Actual capabilities
| Model | Devices | Users | Groups | Communication | Photo verification |
|---|---|---|---|---|---|
| Hub | 100 | 50 | 9 | Ethernet + GSM | No |
| Hub 2 | 100 | 50 | 9 | Ethernet + 2 SIM | Yes |
| Hub 2 LTE/4G | 100 | 50 | 9 | Ethernet + 2 SIM 4G | Yes |
| Hub 2 Plus | 200 | 200 | 25 | Ethernet + Wi-Fi + 2 SIM 4G | Yes |
| Hub Hybrid | 100 | 50 | 9 | Ethernet + 2 SIM, wireless and wired | Yes |
Two figures deserve careful reading. The number of sirens and keypads is capped at 10 combined across all hubs, and the number of ReX repeaters at 5. These limits are reached well before the overall device limit.
How to decide
Apartment or house — a Hub 2 is more than sufficient. One hundred devices is five to ten times what a home actually uses. Don't pay for capacity you'll never reach.
Business, office, warehouse — the Hub 2 Plus is justified by three concrete criteria. The 25 security groups, compared to 9, allow the back room to be armed while the sales floor remains open. The Wi-Fi adds a fourth communication channel where the Hub 2 has three. And the 200 users become useful as soon as there is rotating staff.
Unreliable internet connection — choose an LTE/4G version. On the standard Hub 2, both SIMs are 2G: it works, but the 2G network is being phased out by several European operators. This is a choice for longevity rather than performance.
Renovation with existing wiring — the Hub Hybrid simultaneously manages wireless and wired connections. You reuse what's already installed and supplement with wireless.
2. Jeweller or Fibra: wireless or wired?
Jeweller is Ajax's proprietary wireless protocol. It operates between 866 and 926.5 MHz depending on the region, with encryption and frequency hopping, for an advertised range of up to 2,000 meters in open space. Each device communicates with the Hub at an adjustable interval from 12 to 300 seconds: a cut or jamming is therefore reported in a few tens of seconds at worst.
Fibra is the wired version. Up to 2,000 meters of cable per line, no possible radio interference, no batteries to replace.
In practice: Jeweller for everything that already exists, because drilling and pulling cable costs more than the equipment itself. Fibra for new constructions, where conduits are accessible, and for sites where the radio environment is saturated or regulatory requirements are high.
3. Detectors: where and how many
An alarm system is only as good as the placement of its detectors. Three well-placed detectors are better than eight poorly oriented ones.
Motion
MotionProtect is the standard infrared detector, with pet immunity. MotionCam adds a camera that sends a series of images with each alarm. This feature changes daily life: you can confirm or dismiss the alert from your phone instead of rushing home. MotionProtect Plus combines infrared and microwave for challenging environments — conservatories, rooms with drafts, sun-exposed areas.
Openings
DoorProtect detects opening via magnetic contact. DoorProtect Plus adds an accelerometer and a vibration sensor: it detects forced entry attempts before the opening. For an entrance door, this is the preferred model.
Sizing
For a four-sided house, count one motion detector per thoroughfare on the ground floor, one opening detector on each main access point, one outdoor siren, and a keypad near the entrance. Four to six detectors provide adequate coverage. For an apartment, two to three are sufficient.
Installation rule: at approximately 2.4 m high, oriented so that an intruder crosses the field rather than moving directly towards it — an infrared sensor detects transverse movement much better. Avoid: facing a sunny window, above a radiator, opposite an air conditioning vent.
4. Sirens and keypads
The siren is the most underestimated element. A detected but silent intrusion allows the burglar to work undisturbed. StreetSiren on the facade plays as much on visibility as on noise: many break-ins never start because reconnaissance revealed a siren. Install it high, above 2.5 m, on the side most exposed to the street.
Regarding keypads, the KeyPad covers basic needs, the KeyPad Plus adds RFID reading (faster and more discreet than a code typed in front of witnesses), the KeyPad TouchScreen displays system status and manages groups. All integrate the duress code, which seemingly disarms while sending a silent alert.
A common sense point often overlooked: never install a keypad on the exterior facade. An externally accessible keypad is a weakness, not a convenience. If you need to disarm before entering, use a remote control or the application.
5. Obligations in Belgium
An alarm system installed in a dwelling must be declared to the federal contact point provided for this purpose. The declaration is made online, it is free, and it must be updated in case of a change of occupant or contact details. It does not impose any remote monitoring contract.
The operating time of an outdoor siren is also regulated. Ajax's default settings remain within usual limits, but check the municipal regulations applicable to your address — they may be stricter.
Finally, if you use an installer, make sure they have the SPF Intérieur accreditation required for security companies. This is a legal obligation, not a commercial label.
6. Is a subscription required?
No. The Ajax Security System application, push notifications, remote control, and event history are included, with no recurring fees. A contract is only necessary to connect the installation to a professional remote monitoring center — which is recommended for a business, less often for a dwelling.
Indicative Budget
An entry-level kit with Hub, motion detector, opening detector, and remote control starts around €390. A Hub 2 kit with photo verification and siren is between €580 and €800. A Hub 2 Plus set for commercial use exceeds €800 before adding detectors. Then count €40 to €150 per additional device depending on the type.
Frequently Asked Questions
Can I install it myself?
Technically yes, installation is wiring-free, and each device is added via QR code. For a business or connection to remote monitoring, use an approved company.
What happens in the event of a power outage?
The Hub 2 has a 2 Ah Li-ion battery, the Hub 2 Plus a 3 Ah battery, for approximately 15 hours of battery life. Detectors are battery-powered and are not affected.
What if the burglar jams the radio?
The Hub detects jamming and signals it as a technical alarm. This is precisely why the interrogation interval matters.
Can I change the Hub later?
Yes. All Jeweller devices can be re-paired with a new central unit. You only lose the reconfiguration time.
Is Ajax compatible with cameras?
Yes, via the application's video integration, and natively with MotionCam devices which have their own camera.
Take Action
View Ajax alarm kits · Compare hubs · Choose detectors · All Ajax products
Unsure about sizing? Write to us at info@securishop.be with a plan and the number of access points to cover: we will validate the configuration before ordering.