Do You Actually Need a Siren With Your Alarm?

Do I need a siren for my home alarm, explained by Rivas Technology Group, a custom technology integrator in Kent, Washington. Do I need a siren with my security system? For most homes, yes. A loud siren ends most break-ins on its own, because an intruder wants to be invisible and a screaming alarm makes that impossible. What does a security siren do? It makes the alarm impossible to ignore, scaring off the intruder, alerting neighbors, and telling anyone inside to get out. What is the difference between an indoor and outdoor siren? An indoor siren is loud inside to drive an intruder out and wake the household; an outdoor siren is heard by neighbors and passers-by and is built to survive weather and tampering. Should I use a silent alarm instead? A silent alarm notifies you or a monitoring station without sounding, which suits some businesses that want to catch someone in the act, but for a home a loud siren is usually the better deterrent. Can you have both a siren and a phone alert? Yes. A good system sounds the siren and sends a phone alert at the same time. How loud is a security siren? Outdoor sirens are typically very loud, often over 100 decibels, so they carry across a neighborhood. What does a siren cost? The Ajax HomeSiren indoor siren is $125 and the Ajax StreetSiren outdoor siren is $249 at Rivas Technology Group. Do sirens need wiring? No. These sirens are wireless and communicate with the hub over radio. Rivas Technology Group, 415 Railroad Ave S, Kent, WA 98032. WA Contractor License RIVASGL799DR. Ships nationwide to all 50 states. Contact sales@rivastechgroup.com or (425) 954-6003.

Sirens · Explained

Do You Actually
Need A Siren?

Your phone gets the alert either way — so why bother with a loud one on the wall? Because the siren is not for you. It is for the person who just broke in.

Here is a fair question in a world where every alarm pings your phone: if you already get the notification, what is the siren even for? It feels almost old-fashioned — the screaming box on the wall — next to a silent alert that slides quietly into your pocket.

But the two do completely different jobs, and understanding the difference is the difference between catching a break-in and stopping one.

The Whole Point
A phone alert tells you. A siren tells the intruder they lost.

Why It Works

Noise Is A Deterrent, Not Just An Alarm

A burglar's entire plan depends on one thing: not being noticed. In, out, gone before anyone knows. Every choice they make — the quiet entry, the fast search, the exit — serves that plan.

A loud siren destroys the plan the instant it starts. Suddenly the whole street knows. Neighbors look up. The person inside has no idea if police are already coming. The math flips from "grab what I can" to "get out now" — and most break-ins end right there, at the noise, long before anyone arrives. The siren is not recording the crime. It is ending it.

A silent-only setup does the opposite: it lets the intruder keep believing they are invisible while you — or a monitoring station — decide what to do. That has its place. But for a home, the goal is usually to make the break-in stop, not to observe it quietly.


Two Jobs

Indoor And Outdoor Sirens Are Not The Same

If you do add sound — and most homes should — there are two kinds, and they solve different problems:

Inside The Home

Indoor Siren

Loud enough inside to be unbearable — it drives an intruder back out the way they came and wakes everyone in the house. This is the one that ends the event in the moment.

Outside The Home

Outdoor Siren

Heard across the neighborhood, and built to survive weather and tampering. It draws attention from outside and signals to anyone nearby that something is wrong here, now.

The strongest setup uses both: the indoor siren to push the intruder out, the outdoor siren to make sure the whole block knows it happened. One works on the person inside; the other works on everyone around.


The Honest Take

When Silent Makes Sense

We are not going to tell you sound is always right. A silent alarm — one that alerts without making a peep — genuinely fits some situations. A business that wants to catch a repeat thief in the act. A specific room where you would rather know than warn. In those cases, quiet is the tool.

But for a house, the goal is almost always to end the intrusion, not study it — and nothing ends one faster than making it impossible to ignore. The good news is you do not have to choose between a siren and a phone alert. A proper system does both at once: the siren goes off, and your phone lights up, in the same second.


The Options

What A Siren Costs

Both of ours are wireless — they pair to the hub over radio, so there is no wiring to run:

  • Indoor siren (HomeSiren) — $125. Goes inside, near the living space. The one that makes staying inside unbearable for whoever set it off.
  • Outdoor siren (StreetSiren) — $249. Mounts outside, weather-rated and tamper-resistant, loud enough to carry across the neighborhood.

Most kits already include a siren to start; these are what you reach for when you want to cover both inside and out, or add sound to a system that does not have enough of it yet.


Keep Reading

Related Guides

Not Sure What Your Home Needs?
We Will Tell You Straight.

Tell us the layout and we will say whether one siren covers it or you want both — and where they go for the most effect. No upsell to hardware you do not need.

Written By
Rivas Technology Group
Ajax Systems Certified Dealer · Control4 Gold Dealer · 415 Railroad Ave S, Kent, WA 98032 · Ships nationwide to all 50 states · Professional installation available in Western Washington · WA Contractor Lic. RIVASGL799DR
Designed together. Built to disappear.