Using ST with a dumb outdoor alarm siren?

I’d like to make my old dumb house alarm smart. But most of the the smart options don’t have an outside siren. Is there any way to get an effective smart alarm to use my existing outdoor siren?
What sort of product would I need to look for?
TIA

Dry contact relay should work. Sending power to the siren makes it go and a relay would allow you to control the power. Or a smart plug with a 12v transformer unit that is wired to the siren.

@Paul_Phelan
What brand is your old (dumb) alarm system? The DSC PowerSeries can be linked to SmartThings and the wired external siren still used by using the Envisalink module. It is however likely the siren would only be triggered by a sensor of that alarm system rather than a SmartThings sensor. However you can arm/disarm it via SmartThings.

See DSC + Envisalink 4 + smartthings-dsc-alarm-server amongst other threads.

By the way, I share your annoyance that all the new so-called smart alarm systems do not offer external sirens or at best only battery ones. This applies even to the unavailable in the UK ADT/SmartThings smart alarm system. You would think a company like ADT would know better.

There is an easy way to implement this in be hub and the Android app. I “assume” it might work in other versions.

Use the new SmartThings Outlet (others may work) along with a supported siren (I use Utilitech) which you might place inside and hour larger siren outside, for example.

Then create a rule (this is in the latest version of the Android app) that looks for the supported siren activation, by fire or burg, doesn’t matter, in the IF stmt, and in the THEN stmt turn on the SmartThings Outlet where the siren, or anything else is powered

You could add a ups for the siren in case of power outage if desired.

There is another benefit from doing it this way. The lights, or that big siren, will start, after an alarm condition, based on the delay setting I this burglar or fire setup.

I hope this helps. I control a number of lights in my backyard office building using Outlets so this works. In my home location I also use this because I don’t want all the lights coming on if I open a door without turning off home monitoring

I have not tried it, but I believe you can create a second IF/THEN rule to turn off the Outlet(s)/siren, etc. When you dismiss the alert. I plan to implement this later today.

Let me know if this works for you.

Thanks for the replies.
Earlier this week our internet service went down (and still is after nearly 48 hours). What this showed me is that I probably no longer want to make my alarm ‘smart’ using a ST hub-like device. Since the internet has been down, none of my smart home features have worked properly - if at all.
Though what continues to work is my dumb alarm and it’s auto-dialler which uses the old copper voice line. Both the system, dialler and siren each have their own battery/ups and continue to work even if power and internet are stopped.
It’s been an eye-opener on how my household depends on connected services and how fragile and fallible they can be in certain situations. I’m not knocking it; I still intend to keep adding to my smart home but I think for something as critical as an alarm, dumb might be best. Unless I can find a smart alarm with an outdoor siren which will use a copper or GSM dialler rather than broadband for notifications.

Depending on who your ISP is, you could just replace your router with one that supports 4g LTE as a fail over (although if smarthings cloud goes down, you’d still be knackered).

I currently have this set up with my router and a few hubs (Smarthings, Hue, Hive & my primary mesh unit) on a UPS, if the internet goes down it switches to 4g backup, if the power goes down the UPS kicks in and should last for about 8 hours. However the router wasn’t cheap and i am paying monthly for the second “line” with my mobile provider that doesn’t really ever get used.

Thanks @AndiMack for the reply.
I’ve come across the Yale SR-330 alarm system but finding it difficult to discover information about it other than what you’d find in a sales brochure. E.g. compatibility with ST, pet sensors, keyfob usage, etc,etc. It’s just not well documented at all which suggests it’s not to the quality I require.

I’ve got a good UPS Outdoor siren which I’d ideally like to keep if possible (it’ll save a trip up the ladder at least), and want to find out if I can make the Yale system work with it instead of it’s own siren.

A previous contributor suggested a way to have the ST hub trigger an external siren using a power outlet (or similar device). An innovative idea for sure, but not a compromise I’m prepared to make.
It’s got to be slick and simple, but most of all robust. I don’t want to have to muck about deep in settings every time the power goes out etc.

What’s your current alarm?

Have you looked at the newer Konnected alarm panel interface?

If compatible, it should give the the best of both worlds, might be worth getting in contact with them.

@Paul_Phelan (Belated reply.)
The Yale SR-330 is a purely wireless product and this includes the official Yale siren.

All the Yale alarm systems are closed systems meaning that they officially do not link to other products. However an enterprising user of these forums did manage to create a Smartthings integration for Yale alarms.

Other than using the official Yale wireless i.e. battery siren you could in theory use the above integration to Smartthings and then have a webcore rule which turns on a separate siren e.g. a Z-Wave or Zigbee siren or a dumb siren controlled by a smart relay or socket.

I use a few of these, strategically placed outside, powered by a DC adaptor and smartplug.

Plus a couple of these, used in the same way.

Looks ace. And the blue strobe sat on the side of the garden shed in a dark garden really gives the impression that security is spot on. Been up and running since oct '18.