Ajax Sirens: HomeSiren, StreetSiren & DoubleDeck — UK Installer Guide

Ajax sirens are the loud, visible end of every wireless intruder system you fit — and choosing the right one matters more than installers often assume. This guide is written for UK CCTV and security installers specifying an Ajax alarm: it covers the three wireless Jeweller sirens you can buy and ship today — the indoor HomeSiren U, the outdoor StreetSiren, and the outdoor StreetSiren DoubleDeck with its branded faceplate — with real decibel ratings, IP ratings, range figures and placement rules so you spec the correct sounder first time.

At a glance

HomeSiren U Jeweller — indoor only, up to 100 dB, LED Connector support, ~5-year battery. Use it inside to startle and disorient an intruder.
StreetSiren Jeweller — outdoor sounder, up to 113 dB, IP54, up to ~1,500 m Jeweller range, tamper-protected. The standard external bell-box. No branded faceplate.
StreetSiren DoubleDeck Jeweller — outdoor sounder, up to 113 dB, IP54, up to ~1,700 m range, tamper and accelerometer, plus the Brandplate faceplate you can print your own logo on.
All three are wireless Jeweller devices, configured from the Ajax app, with up to five years on pre-installed batteries.

Ajax sirens installer guide: HomeSiren, StreetSiren and StreetSiren DoubleDeck — Ajax’s three buyable wireless sirens: indoor HomeSiren U, outdoor StreetSiren, and the brandable StreetSiren DoubleDeck.

Which sirens does Ajax make?

Ajax makes one indoor wireless siren and two outdoor wireless sirens in its baseline Jeweller range, plus wired Fibra and Superior variants for larger and certified systems. For a typical UK wireless install you are choosing between three devices: the Ajax HomeSiren U Jeweller (white) or HomeSiren U in black indoors, and outdoors either the StreetSiren or the StreetSiren DoubleDeck. All three speak the Jeweller two-way radio protocol back to an Ajax hub, so they drop into any Hub 2, Hub 2 Plus or Hub Hybrid system without extra wiring.

A complete deterrent uses both: at least one external siren so the alarm is heard and seen from the street, and an internal siren to make the inside of the property unbearable to stay in. Light-only signalling is not enough — from a distance an LED can be missed, which is why every Ajax siren pairs a loud piezo buzzer with a bright LED frame.

HomeSiren U: the indoor sounder

HomeSiren U is Ajax’s wireless indoor siren, reaching up to 100 dB and designed to make a protected room hostile to an intruder. Volume is adjustable in the app — Ajax quotes roughly 80 dB on the “Quiet” setting and 93 dB on “Loud” measured at one metre, with a peak of around 100 dB (HomeSiren technical specifications). It runs for up to five years on its pre-installed batteries and reports their status back to the app, so you are warned before one dies.

The “U” revision adds support for the Ajax LED Connector, letting you wire a discreet LED strip to the siren for visual armed/disarmed indication — useful in retail and reception areas. Fit the HomeSiren U in white or black high on a wall, ideally near the centre of the property where the sound carries to every room. Indoors you can also use it as a chime to announce door openings while the system is disarmed.

StreetSiren: the outdoor workhorse

StreetSiren is Ajax’s standard external wireless sounder, rated up to 113 dB with an IP54 weatherproof enclosure for unsheltered walls. Its piezo buzzer is adjustable from 85 to 113 dB with an alarm duration from three seconds to three minutes, and it communicates with the hub at up to roughly 1,500 m line of sight over Jeweller (StreetSiren technical specifications). A built-in tamper alerts you the instant anyone tries to open or remove it, and even if the hub briefly drops offline the siren still responds to detector alarms locally.

Choose StreetSiren when you want a dependable, lower-cost external bell-box and do not need a printed faceplate. It is available in white and black. Note this model is not compatible with Ajax Brandplates — if you want your logo on the box, you need the DoubleDeck below.

StreetSiren DoubleDeck: the brandable outdoor siren

StreetSiren DoubleDeck is the premium outdoor siren, matching the 113 dB output and IP54 rating of the standard StreetSiren but adding a clip-lock Brandplate faceplate, an accelerometer, and longer Jeweller range of up to around 1,700 m (Ajax StreetSiren DoubleDeck). The buzzer runs 85–113 dB for a configurable 3 seconds to 3 minutes (up to 15 minutes on current firmware), it carries pre-installed CR123A batteries good for about five years, and it accepts a 12 V external supply with seamless fallback to battery.

The accelerometer is the practical upgrade over the plain StreetSiren: it detects any attempt to move, prise or dismount the unit and notifies the app and ARC immediately, on top of the standard tamper button. Mount it with the SmartBracket, pair by scanning the QR code, and reconfigure it remotely afterwards. Fit the DoubleDeck in white or black at 2.5 m or higher for audibility and to keep it out of easy reach.

What is the Ajax Brandplate — and why it sells jobs

The Brandplate is a customisable faceplate that clips onto the StreetSiren DoubleDeck so you can display your own logo and contact details on every install. In other words, every external siren you fit becomes a free advert for your business on a customer’s wall, catching the eye of neighbours and passers-by who may need an installer themselves. It is the single strongest reason to specify DoubleDeck over the plain StreetSiren.

Brandplates are sold separately from the siren in batches of ten, in white or black, and Ajax provides a free print of one design when you order four batches (40 panels) or more, composed in the online Brandplate constructor (Ajax Brandplate). Trying it on one site first? Grab a single white Brandplate to test your artwork before committing to a print run.

Ajax siren comparison: HomeSiren U vs StreetSiren vs StreetSiren DoubleDeck specifications — Side-by-side decibel, IP and range figures for the three Ajax Jeweller sirens.

Ajax siren comparison table

Use this table to match the siren to the job — indoor versus outdoor first, then branded versus plain for the external unit.

Feature	HomeSiren U	StreetSiren	StreetSiren DoubleDeck
Use	Indoor only	Indoor / outdoor	Indoor / outdoor
Max volume	Up to 100 dB	Up to 113 dB	Up to 113 dB
IP rating	— (indoor)	IP54	IP54
Jeweller range	Up to ~1,500 m	Up to ~1,500 m	Up to ~1,700 m
Tamper	Yes	Yes (button)	Yes + accelerometer
Brandplate	No	No	Yes (clip-lock)
Battery life	Up to 5 years	Up to 5 years	Up to 5 years
External 12 V power	—	Yes	Yes

Figures from Ajax Systems product and specification pages. Volume measured at 1 m; range quoted line-of-sight over Jeweller.

How many sirens does an install need?

For a credible deterrent, fit at least one external and one internal siren on every Ajax system. The external unit warns the street and signals an audible response; the internal unit drives the intruder out by making the inside intolerable. On larger or higher-risk sites, two external sirens on different elevations remove the “blind side” an intruder could attack quietly.

A common, cost-effective tactic is to pair a live StreetSiren DoubleDeck on the visible elevation with a matching DoubleDeck dummy siren (white) or dummy in black on a second wall — identical appearance, no extra device on the hub, double the visual deterrent. Many Ajax kits already bundle both an internal and external siren, so check what the kit ships with before adding singles.

Six steps to add and configure an Ajax siren in the app — Adding and configuring an Ajax siren: scan, mount, set volume, assign triggers, test.

Siren placement and wiring tips

Mount external sirens at 2.5 m or higher to maximise audibility and keep them out of reach. Ajax sirens are wireless, so there is no cabling to run for signalling — but both StreetSiren models accept a 12 V external supply if you want mains backing with battery fallback, which suits sites where you would rather not change cells in five years’ time. Always test the tamper and, on the DoubleDeck, the accelerometer after fixing, and confirm Jeweller signal strength reads two or three bars at the mounting point; add an Ajax range extender if a far corner is marginal.

Set the alarm duration and volume per site — a quiet residential street rarely needs three full minutes at 113 dB, while a noisy industrial estate will. You can also choose exactly which detectors trigger each siren in the app, so a garage PIR need not sound the bedroom-floor internal siren at 3 a.m.

Pairing sirens with an Ajax hub or kit

Every Ajax siren pairs to a hub in the app by scanning its QR code, then appears as a configurable device you can group, mute or trigger. If you are starting a new job from scratch, an Ajax kit is usually the quickest route: the Hub 2 Kit 1 and Hub 2 Kit 3 both ship with internal and external sirens alongside detectors and key fobs or a keypad, and the Hub 2 DoubleDeck Kit 1 bundles the brandable DoubleDeck. For help choosing the control panel, see our Hub 2 vs Hub 2 Plus guide and our Ajax StarterKit guide.

Sirens are only half the system. Match them with the right detectors — see our Ajax MotionProtect vs Pyronix KX comparison — and the right arming method in our Ajax keypad comparison. Browse the full Ajax line-up on our brands page.

Frequently asked questions

How loud is an Ajax StreetSiren?

Up to 113 dB at one metre, adjustable down to 85 dB, for both StreetSiren and StreetSiren DoubleDeck. The indoor HomeSiren U peaks at around 100 dB.

What is the difference between StreetSiren and StreetSiren DoubleDeck?

Both are 113 dB IP54 outdoor sirens. The DoubleDeck adds a clip-lock Brandplate faceplate for your logo, an accelerometer for anti-removal detection, and slightly longer Jeweller range. The standard StreetSiren is not Brandplate-compatible.

Are Ajax sirens wireless?

Yes. HomeSiren U, StreetSiren and StreetSiren DoubleDeck are wireless Jeweller devices that run up to five years on pre-installed batteries. The outdoor models also accept an optional 12 V external supply.

Can I put my own logo on an Ajax siren?

Yes — on the StreetSiren DoubleDeck only, via the Brandplate faceplate. Brandplates are sold in packs of ten and Ajax prints one design free when you order 40 panels or more.

How high should an outdoor Ajax siren be mounted?

At least 2.5 m, for audibility and to keep the unit out of easy reach. Test the tamper and accelerometer after fixing and confirm a stable Jeweller signal at the mounting point.

Do Ajax alarm kits include a siren?

Many do. The Hub 2 Kit 1, Hub 2 Kit 3 and Hub 2 DoubleDeck Kit 1 all ship with both internal and external sirens, so check the kit contents before ordering separate sounders.

Order Ajax sirens with same-day dispatch

Netview stocks the full Ajax siren range — HomeSiren U, StreetSiren, StreetSiren DoubleDeck, Brandplates and dummy sirens — in white and black for fast trade dispatch from Leicester. Browse the range and order online at netviewcctv.co.uk.

Trade account holders get live pricing and stock on every Ajax line at netviewcctv.co.uk.

June 24, 2026 | View: 35 | By: netviewcctv.co.uk