The Siren Test!
Battery Back-up Sirens are a basic requirement for any 5 star rated alarm. Being the part of the alarm that screams for your attention it is arguably the most important part of the alarm. I decided to put the major brands to the test to see how effective they are.
Before looking at the sirens I shall explain the different terms:
Digital Battery Back-Up Siren: These communicate with the alarm via a data wire so know if the alarm is armed or disarmed. As the siren knows the state of the alarm there is no need for an over-ride key so the siren can be hidden.
If the alarm is disarmed then the vehicles battery can be disconnected and the siren will not go off, this means that the Digital Battery back-up siren is not only easier to live with but also offers a higher level of protection.
Basic Battery Back-Up Siren: These sirens trigger when they detect a negative or positive pulse input, They are cheaper to to manufacture than Digital Battery Back-up Sirens and have no way of knowing if the alarm is armed of disarmed. Because of this disconnecting the power to them causes the siren to sound even if the alarm is disarmed. To get around this problem they have an over-ride key which will disable the siren. Due to this the siren needs to be accessible which makes it vulnerable to attack.
The Battery Back-up Siren Review…
Autowatch Siren
The Autowatch Siren is of the Digital Variety, hence is has no over-ride key to worry about and can be hidden for that extra level of protection. It has soft arm/disarm chirps or can be programed to silent arming (actually silent arming isn’t strictly correct a it gives a very discreet blip). The Autowatch comes a very respectable second here. It is not as loud as the excellent Cobra and does not offer arm/disarm volume control.
Obsessive Rating 8/10
Apart from the Cobra the Autowatch puts the others to the sword!
AVS Siren
The AVS Siren is a data siren, this means that it can not be tricked into being silenced by tampering with the wires as it does not rely on a negative or positive trigger wire. So whilst it is better than the Basic battery back-up sirens found with Dynatron, Mongoose and Meridian it still has an over ride key and needs to be accessible. Despite the sales spin from AVS the siren is still easy to defeat and should not be confused with the digital sirens found with the Autowatch and Cobra alarms.
Obsessive Rating 3/10
Let down by over-ride key!
Cobra Siren
The Cobra Siren is a Digital Battery Back-up one, it is extremely solid and better still has a very high pitch sound. It is certainly the loudest and most attention grabbing of the brands on offer here. The other great thing with the Cobra siren is that the Arm/Disarm chirps can be adjusted in volume to suit the owner.
The Cobra siren is so advanced that it will even give a diagnostic warning if it has been tampered with!
Obsessive Rating 10/10
So good that the Obsessive Wagon has 2 of them!
Dynatron Siren
The Dynatron Siren is a basic battery back-up siren with an over-ride key, Dynatron make a large and a small version but both need to be placed in an accessible location for the over-ride key access.
As with the AVS, Mongoose and Meridian siren this simply defeats the whole point of the siren being Battery Back-up!
Obsessive Rating 2/10
Go for the 4 Star Dynatron -At least the siren can be hidden!
Meridian Siren
The Siren found on Meridian alarms is a basic Battery back-up design, It is the same siren that is found on the old generation AVS alarms before they upgraded to the AVS data siren.
Whilst it is much better than the Meridian alarm what it comes with (probably because it made by someone else) it still isn’t very effective and is best avoided.
Obsessive Rating 2/10
More over-ride keys…..
Mongoose Siren
The Mongoose siren is another basic battery back up system with an over-ride key. It comes with bullet connectors which is a concern as unplugging the trigger wire and grounding will it disabled the siren in seconds! The bullet connections really should be cut off and the wires soldered and taped.
Obsesive rating: 1/10
Would be 2/10 if not for the poor Bullet connectors!
Don’t be fooled by the Mongoose website. The claim that their sirens are Digital are in my opinion very misleading. The bottom line is that all Mongoose battery back up sirens come with an over-ride key and therefor offer sod all protection!
Pingback: 5 Star Car Alarms | Obsessive Vehicle Security Blog
Pingback: “NZ rating system for alarms is a crock of shitemonkeys…” | Obsessive Vehicle Security Blog
Here’s a “You Tube” video one of my customers has posted with a great recording of the Cobra Siren in action. Action kicks in @ 2 minutes and 50 seconds!
http://vehiclesecurity.co.nz/blog/mr2-security-install
Presumably a digital backup siren will go off if its comms cable is cut while the system is armed? That seems like the whole point of a battery backup but just checking.
Hi Rick,
Yes the siren will go off if it is armed and any of the cables are tampered with. If it is disarmed then you are OK to disconnect the battery, hence why I can hind them or make them difficult to get to.
Pingback: Dynatron 7800 VS AVS S5
Pingback: NZSA Standards…… | Obsessive Vehicle Security Blog
Pingback: 5 Star Muppetry! | Obsessive Vehicle Security Blog
Pingback: Cobra AK4138 | Obsessive Vehicle Security Blog
I have an AVS S5 Alarm, and I read your blog and find it really interesting, I was wondering if I wanted the Cobra decent siren, would it be compatible with my existing S5 system and could just be wired in? or is this not an option
Hi Mike,
Unfortunately the Cobra Siren can only be hooked up to Cobra alarms. It communicates with the Cobra alarm module via a BUS communication wire.
Pingback: Cobra AK4615 | Obsessive Vehicle Security Blog