I wanted to install a siren/speaker in my attic and connect it to Output 2. I wanted to do this so that my neighbors could hear my alarm. I installed an ELK-SP40, but that isn't loud enough. I can barely hear it when I am outside, next to my house. Would the Elk-45 work better for me? Perhaps I should just use an interior siren alarm instead. What do you guys have setup for sirens?