Why outdoor noise makes the difference

The longer someone is visibly and audibly at work, the greater the chance that a neighbour comes to look. That is why they look for homes where nothing happens: no sound, no alert, no neighbour who wakes up.

Good doors slow a burglar down, but they do not stop him. Your aim: make the clock run against the burglar. That starts in the garden, on the terrace or at the drive — not when the bedroom door opens.

An apartment has no garden line. Detection there is at the door and inside. The outdoor siren then wakes the building.

That is why we combine outdoor detection with loud outdoor sirens. The sensor sees movement; the siren makes it impossible to keep working unnoticed. The burglar knows: here I am heard. He often leaves — and looks for a house where that does not happen.

If the volume is high enough, someone does react. Our experience: more than 100 burglars ran when the outdoor siren came on by itself, from alarm sensors in the garden. While the siren was sounding, no break-in was completed. Watch the real break-in attempt.

Many subscription systems do not detect signal interference well — so you are not called either. If the outdoor siren is missing and the system does not react to interference, you have nothing on the spot to drive a burglar away.

Waiting until someone calls you, so you can then say the police should come, is not a plan. That takes tens of minutes. The chance that the police come is small.

If the burglar uses a jammer, the monitoring centre knows nothing. You are not called. If you are not called, the police do not come either: nobody knows that anything is happening.

Even without a jammer it takes too long. Often two alarm sensors must be in alarm before a monitoring centre may call the police. By then the person is gone.

An outdoor siren that wakes the whole street the moment someone sets foot in the garden is far more effective. You get that moment with sensors outside. That is how you stop it becoming a completed break-in.

In our experience as owners in Spain: speed is rarely guaranteed if you do not act yourself. See monitoring centre research. We install subscription-free AJAX systems: you own it, you get direct alerts, and the outdoor siren does the work a call centre cannot — scare on the spot. More on misleading promises: 6 pitfalls when buying alarm systems.

An intruder will do anything to stop the siren from sounding and waking the street. The simplest way for a break-in to succeed is to choose a home with no outdoor siren.

At the largest subscription-alarm providers that siren is missing completely. At most of them, not even a real indoor siren is fitted. What is there is a buzzer in the keypad by the front door. That is easy to sabotage.

The first question when choosing an alarm is therefore: is there an outdoor siren, and how loud is it?

Today everything is wireless. Wireless is quick to fit, and also easy to interfere with. Ask whether the wireless signal is watched. And ask what happens if someone interferes with that signal with a jammer. Do you only get an alert on your phone, or does the siren also sound at the moment it can no longer be reached wirelessly?

A siren that hears a jammer itself and then sounds on its own is a Grade 3 siren. At Ajax that is the Superior StreetSiren Plus G3 Jeweller. It gives 107 dB.

The StreetSiren Jeweller is Grade 2. It has no jamming detection in the siren itself, and it gives 113 dB. The Ajax hub does always watch the wireless signal. With Grade 3 rights we set this siren so that it already sounds when interference is detected, well before the signal is disturbed so badly that the siren can no longer be reached and would stay silent.

We have those Grade 3 rights in the Ajax PRO app. A standard Ajax installer does not. He cannot turn this setting on, and he cannot install the Grade 3 line.

With both sirens, the siren can also sound when a sensor goes offline, as long as the siren itself is not interfered with. Because we already make the Grade 2 siren sound when interference is detected, it matters less with us whether you choose the StreetSiren Jeweller or the Superior StreetSiren Plus G3 Jeweller.

Pitfall 4: jamming and signal interference explains what a jammer is, and why it is dangerous.

Jamming: promises, a practice test and questions for the salesperson sets the sales promise next to what we saw when we switched a jammer on.