multiple sensors on optional sensor port?

Brown lead from alarm CPU plug H1 to 86 on relay, 85 to ground, 12v+constant at 5amps fused to 30, siren from 87 OR BROWN / black from alarm CPU* plug H2 to relay 85, live 12v+ at 5amps fused to 86 and 30, output to siren from 87. The second method will give you pulsing sounds, you could also use air horns instead of the second siren.

Don't need full size relays, DEI sell a small pre-wired relay, I think part # 8166 for less than the normal relay peice or you can get them from Radio Shack, 12volts 5 amps for about $1.20 e.a.