Hi,
I would also like an outside Siren / Speaker blasting out at high decibels. My entire street has triple glazed windows and when they are all shut and you can hardly hear the base station outside.
I set the siren off went next door to my neighbour and with their windows and doors closed we couldnt even hear the alarm sounding.
My Base station is located on the ground floor next to 8 ft from the external wall and 10 ft from a window.