Compare subscription alarms: what happens in minute 1 of a break-in?

On paper every alarm system sounds the same: “secured”, “24/7”, “anti-jamming”. What really matters: what happens in minute 1 of a break-in — outdoors, on your phone, and if the radio signal is jammed. On this page you see how that typically looks with a subscription — and how we handle it differently.

Guides · minute 1

Ownership & contract → Pitfall 1

Below we focus on what happens in that first minute: whether a siren sounds, whether you get an alert yourself, what happens under jamming, and what a monitoring centre in Spain may and may not do. More on ownership, monthly fees and “free” installation is in Pitfall 1.

What happens in minute 1 of a break-in?

Many people sign up for a subscription after a short sales pitch at the door or on what the brochure promises. Only later do they notice what does not happen when someone is on the drive: no loud outdoor siren, no immediate phone alert, silence when the signal is jammed, and a monitoring centre that in Spain may not call the police on its own.

What salespeople rarely state clearly: no subscription alarm sold door-to-door is Grade 3 certified under EN 50131 — the highest European level for professional intrusion protection. That is an objective hardware quality gap, separate from the monthly fee.

On what a monitoring centre may and may not do in Spain: Pitfall 2: monitoring centre false security.

Four questions before you sign

Ask these of every salesperson who wants you to sign for an alarm system — and listen whether the answers about noise, alerts and jamming are concrete.

Imagine this

It is 03:00. Someone walks up your driveway. You are asleep. Your neighbours are asleep. What does your alarm system do — outside, on your phone and at the monitoring centre?

With most standard subscription packages we come across, protection falls short on three or four of those points — too little happens, too late, or nothing at all.

Question 1

Does a loud siren sound outside?

Not a quiet beep on an indoor panel — but noise your neighbours hear, that drives an intruder away immediately and that also works when nobody is home to respond to an alert.

Typical subscription: usually not

Question 2

Do you get an alert straight away?

With many subscriptions the alarm goes to the monitoring centre first — not to your phone. Only then does an operator call you. Don’t answer? Nothing further happens. The question is: do you get an alert on your phone within seconds?

Typical subscription: often delayed or via monitoring centre

Question 3

Does it still work if someone blocks the radio signal?

A jammer is a small signal jamming device that cuts the radio link between sensors and hub. Ask then: does a siren still sound, do you get an alert, or does everything stay silent as if nothing is happening?

Typical subscription: in our test often nothing

Question 4

Is the monitoring centre allowed to call the police itself?

In Spain a private monitoring centre may not call the police without first reaching you — or a contact person you have designated. That is the law, regardless of what a salesperson promises on your doorstep.

Not allowed — regardless of the advertising

The chain you need to understand

Intruder on driveway→Jammer on→System silent→Monitoring centre hears nothing→No siren outside→Walks in undisturbed

Almost every alarm system installed today is wireless. That makes installation easier — but your protection depends on a radio link between sensors, siren and hub. A jammer is a signal jammer designed precisely to cut that link. The problem is not wireless technology itself: it is that many subscription packages do nothing on site during disruption — no siren, no alert, no response where it matters. With almost every standard subscription alarm system we come across, the whole system then stays silent, the monitoring centre hears nothing, while the intruder carries on.

Outdoor detection as an upgrade does not fix that. Even with expensive outdoor sensors: if the wireless signal is not monitored and nothing sounds locally during disruption, you are paying for detection without a real response on site.

Portable signal jammer — Illustration: a portable signal jammer. It switches off the radio link — sensors report nothing, no siren, no alert on your phone, monitoring centre hears nothing.

At a glance

Our installation Typical subscription

Minute 1 of a break-in	Typical subscription	Our installation
Outdoor deterrent	✗ Often no outdoor sirenIn the base package the alarm often only sounds on a quiet indoor panel. Your neighbours hear nothing; an intruder on the driveway notices little.	✓ Loud outdoor sirenNoise that you, your neighbours and the intruder hear immediately. The goal: drive the intruder away on site, before they get inside.
Outdoor detection	✗ Mainly detects indoorsThe standard package usually covers doors and windows indoors. Detection on driveway, garden or terrace is often an expensive upgrade — or missing altogether.	✓ Detection before the house, as standardDuring a home visit we determine where someone is first visible: driveway, garden, terrace. The break-in is signalled before anyone enters your home.
During signal disruption	✗ Often silent during disruptionDuring jamming or signal loss the system often does not notice. No siren, no alert on your phone — as if nothing is happening.	✓ Siren and alert keep workingDuring signal loss or sabotage the outdoor siren still sounds and you get an alert on your phone straight away — no monitoring centre in between.
Certification (EN 50131)	✗ Never Grade 3No subscription alarm that sales representatives offer on your doorstep achieves Grade 3. That highest European level — including protection against sabotage such as jamming — is structurally absent here.	✓ Grade 3 available (AJAX)AJAX is the only brand with a fully wireless Grade 3 system: the highest certification level for professional intruder alarm systems.
Police needed?	✗ Monitoring centre may not call police itselfIn Spain a monitoring centre must reach you or a contact person first. If you do not answer, nothing further can happen — regardless of what the salesperson promises.	✓ In practice almost never neededIn all registered break-in attempts at our customers, the outdoor siren drove the intruder away on site. The problem is resolved before police or monitoring centre come into play.

Comparison based on common subscription packages and our standard installation approach. Individual providers may differ.

The table shows the difference in broad terms. For your home, what matters is what is actually installed — and what happens when things go wrong. You cannot read that from a subscription brochure or a five-minute doorstep pitch.

What a home visit with us involves. That is why we start with a home visit. We do not come to sell a contract, but to assess your property thoroughly — driveway, garden, doors, windows, weak points — and determine how a break-in is prevented, not how you discover one after someone is already inside.

Based on that, we explain how a bespoke AJAX installation protects differently from a standard subscription package: outdoor detection, a siren that sounds even when the connection drops, and a response that still works during signal disruption — with sabotage such as jammers in mind. No monitoring centre that has to wake you first. No scenario where nothing happens if you do not answer the phone.

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More than 3,000 installations since 2019 · Google rating 4.8 · accredited Ajax Systems Partner