new siren for prestige aps 996

I have a prestige aps 996 alarm and the siren is not to loud. I would like someone to tell me what is the best siren for this alarm. I want a real loud one. I am not sure if someone makes a 140 or 150 db siren but thats what I am looking for.

Personally, I think the loudest siren you can get is your horn.(factory car horn) I've done alarms with 4 and 5 sirens that are loud as all hell. I've also done alarms with only one or two sirens, and the factory horn hooked to a flasher to make it honk on and off. Those are so loud that they can wake the dead. The only bad part about it is, tapping into the horn wires to make it flash properly you need to tap in AFTER the horn relay which usually means tapping in somewhere under the hood or even at the horn itself. But the advantage is that its very loud, plus your car stands out from the rest. People hear alarms go off all the time and say "is that mine ?", but if you hear a siren AND a horn at the same time, you know dam good and well its yours! Another benefit is from theives. Some professionals know how to reach from underneath your car and cut the siren wire and then they break into your car and rip out the alarm. But they usually dont think to cut the horn wires too.

Cutdog's advice is good. Factory horns can be pretty loud. Since the APS996 has a dedicated horn-honk output, you won't need to use the flasher or anything. Also, your siren may just be mounted in a lousy location---make sure it's someplace where it's easy for the sound to get out.