I have an 8 channel KGuard DVR with no alarm output but, audio out RCA jack that plays a buzzer for various amounts of time minimum 30 seconds maximum 5 minutes. I purchased an mp3 siren that will play up to 4 different mp3 files from 4 different trigger wires. I recorded a barking dog mp3 file and want it to play instead of the buzzer. Would it be possible to connect the siren to the audio out connection to use the audio out as a trigger? The siren needs a 12V power supply. Would I need a relay to trigger the siren and would the audio out buzzer be enough to trigger a relay? Would it complete the circuit if I wired it without a relay or would I short out my DVR?