Alarm siren buying guide
Updated: 20.10.2026
You are looking at sounders that all call themselves a burglar alarm, and every title is shouting about decibels. This alarm siren buying guide is the order to use before you sort by price. You should leave knowing whether you need a two-wire 12 V horn, a Ring accessory, or a graded bell box. The four kept listings are on the [siren comparison](/hub/burglar-protection/siren). Peter F. compared those amazon.co.uk listings and public UK guidance. We did not measure sound in a lab. A qualifying purchase can earn us a commission at no extra cost to you.
You are looking at sounders that all call themselves a burglar alarm, and every title is shouting about decibels. This alarm siren buying guide is the order to use before you sort by price.
You are looking at sounders that all call themselves a burglar alarm, and every title is shouting about decibels. This alarm siren buying guide is the order to use before you sort by price. You should leave knowing whether you need a two-wire 12 V horn, a Ring accessory, or a graded bell box. The four kept listings are on the siren comparison. Peter F. compared those amazon.co.uk listings and public UK guidance. We did not measure sound in a lab. A qualifying purchase can earn us a commission at no extra cost to you.
Our top picks
| Badge | Product | Power | System | Grade stated | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Switian Switian 12 V sound and light siren | 12 V DC, 320 mA | Two-wire horn | Not stated | 8.8 | about £8.99 | View offer |
| Best value |  Switian Switian wired mini siren | 12 V DC, 320 mA | Two-wire horn | Not stated | 8.6 | about £7.99 | View offer |
| Alternative |  Ring Ring Alarm Outdoor Siren | D cells in the box | Ring Alarm only | Not stated | 0.0 | about £69.99 | View offer |
On this page
What you are actually buying
A burglar-alarm siren is the sounder that warns people the system has triggered. It is not a megaphone or a plastic dummy. Texecom’s Odyssey X range includes a dummy backplate with no sounder.
A panel beep wakes the people inside. A bell box is meant for the street. The cheap units here are small wired horns. The Ring unit is a wall box for one named system. None of the four listings states Grade 2 or Grade 3.
Match the system first
Start with the panel you already have. A two-wire 12 V horn needs a trigger that can supply the current, and both clear Switian listings rate the horn at 320 mA. A five-terminal bell box is not the same part. Konnected’s UK note says not to pull wires off an old panel to find out.
The Ring outdoor siren, at £69.99, requires a Ring Alarm base station. WME’s notes say a wireless box has to speak that panel’s protocol. Cable against that radio is on wired or wireless alarm siren.
Power, weather, and the decibel claim
UK mains are about 230 V. The £7.99 and £8.99 horns are listed as 12 V DC. The £9.49 page says 220 V, 220–240 V, and model Sirene 24V in different fields. Fixed mains wiring is an electrician’s job, and a plug for a socket needs to be BS 1363.
The 12 V horns say moisture proof and give no IP rating. The £9.49 bullets claim IP54. Ring’s own UK page states IP66, which is the brand’s claim. All three Switian titles print 120 dB with no distance. Loud still has to stop.
Grade, only when you need it
BS EN 50131-4:2019 is the warning-device standard. None of these four listings states it. An ungraded horn around £8 can still make a noise. It does not document cover tamper or a battery if the cable is cut. One Odyssey 1E page showed both £39.94 and £33.28, so treat trade prices as unstable.
Leave the set when a written Grade 2 specification asks for a device that states the grade. The 20-minute council figure is a timer, not a grade. It is set out in how long a burglar alarm can sound.
A short way to choose
If you already have Ring Alarm and you can mount a box at height, the outdoor siren is the match in this set. If you have a 12 V output and you want a light, the £8.99 Switian is the top pick. If you only need the horn, the £7.99 unit is the best value. Leave the £9.49 listing until the voltage conflict is resolved. If you need tamper and a battery, that graded box is outside these four cards.
Common questions
Do I need a siren if the panel already beeps inside?
An internal beep wakes the people in the house. An external sounder is for the street and a visible flash if the unit has one. You can live with the panel alone in a flat where a long outdoor blast would be the problem. The beep does not replace a bell box.
Will any 12 V horn work on my panel?
Only if the panel can supply the current. The two clear 12 V listings are rated at 320 mA. A reviewer ran the £7.99 horn at a few volts as well as 12 V, which shows noise at low voltage. It does not show those two wires will satisfy a bell box that expects hold-off and tamper.
Is 120 dB a measured figure I can compare?
Not on these listings. The three Switian pages print 120 dB and do not say at what distance or with what weighting. Reviewers both praise the horns and dispute the number. Ring states over 100 dB at 1 metre on its own support page for the loudest setting, which is a different claim and still the manufacturer’s. Do not rank the four products as a measured league table.
Do these amazon listings include a Grade 2 bell box?
No. These four listings do not state BS EN 50131-4 or a grade. A Grade 2 box from a trade brand is a different product, usually with tamper and a battery. If a specification names the grade, an ungraded horn does not meet it by being loud.
Can I use the Ring outdoor siren without Ring Alarm?
No. The listing says it requires a Ring Alarm base station and works with 1st and 2nd generation Ring Alarm devices and accessories. It is not described as a universal wireless siren for another panel. At £69.99, before any adapter, battery pack, or solar panel, it is an accessory for a system you already own. Pairing it to a different panel, or to a bare 12 V output, is the wrong job.
When is the cheap horn the wrong purchase?
When you need tamper, a backup battery, a stated grade, or a supply the listing cannot agree. The £7.99 and £8.99 horns are ungraded two-wire sounders. The £9.49 page conflicts on voltage. The Ring box is the wrong purchase if you do not own Ring Alarm. Call an installer when the old cable cannot be identified, tamper hold-off is unclear, or any joint is fixed 230 V.
Related pages
Sources
Public UK sources used for this comparison, last checked on 19.10.2026.
- GOV.UK, noise nuisances: how councils deal with complaints (retrieved 19.10.2026)
- Clean Neighbourhoods and Environment Act 2005, Part 7 (retrieved 19.10.2026)
- Control of Noise at Work Regulations 2005, regulation 4 (retrieved 19.10.2026)
- BSI, BS EN 50131-4:2019 warning devices (retrieved 19.10.2026)
- Ring UK, Alarm Outdoor Siren information (retrieved 19.10.2026)
- Ring UK, duration of a Ring Alarm siren (retrieved 19.10.2026)
- North Yorkshire Council, alarm noise (retrieved 19.10.2026)
- Texecom Odyssey X external sounders (retrieved 19.10.2026)