How do you test the 105db siren?

Set the system off again! (You should call SS and put your system into "test mode" so you can actually test the full system) or, you can just set off the system and have an alarm event and punch in your code before the 30 seconds is up.

Mine doesn't go off at all. Waiting answers on this forum and email from customer service.
Batteries good.
New outta the box, no chirp, doesn't do anything.

@kirkgillaspey, saw your other post and answered there. If SS2, you must sync it with the base. Instructions are in the owners manual, download at the customer support center.

I put the system in test mode, pressed button on siren and didn't get any response. Appears I'm not the only one having issues with a dead siren unit.

I have a Gen 3 system. Remove your keypad from the wall mount and carry it with you from one extra siren to the next, I have 3 extra sirens. Press and hold the red panic button on top of the keypad for 2 seconds, or if you have a an accessory panic button press and hold it for 2 seconds. The extra sirens will sound instantly.

Enter your PIN to turn off the sirens. If you have multiple sirens, go from one to the next and test each separate. Good idea to do it during the day so as not to disturb or scare the neighbors. :)

Voila!