XL MINI PIEZO SIREN

This really is painfully loud, after a 2 second burst your ears will be ringing for 10 minutes. If you hold the unit, it almost feels like a beating heart. Creepy.
Incredible sound power in a tiny package. I'm buying more of these!

To the last poster: you cannot put a resistor in series to drop the voltage. Piezos have capacitance which is charged - which results in motion of the ceramic material - which is what you hear. Also, the chip which drives the piezo has a minimum operating voltage to function - which is not met with a resistor in series - due to huge voltage drops as the piezo charges.

To lower the volume, use a REGULATED supply of lower voltage, or if you use a series resistor - a cap across the module - consisting of at least 100 uF - paralleled by a 1 uF ceramic.

These approaches will allow you to get quite a dynamic range.

Nice and compact and yes, It IS! Painfully loud at 12vdc. Even at 9vdc it makes you cringe. I purchased one to use in an alarm setup for the liquor cabinet. Soldered straight to a 9vdc battery and magnetic switch. My wife set it off once by accident. The bruise on my arm proves its loud. =o)
Just hoping my soon to be teenage son and his friends don't find a need to set it off.
Thinking of getting another to wire to a 9vdc battery and toss it in my gun case for added security.

Great but it is VERY VERY VERY LOUD even at 6vdc it is so loud that i want to plug my ears and that is the minimum voltage i havent tryed it at 9 or 12 vdc it works best for my if i put it in line with a 120ohm resistor at 6vdc with a 120 resistor i can have my ears unpluged but i can't stand it for long and if i keep it on with my ears unpluged for more that 10 seconds then my ears hurt for like 15 minutes after that
for me if you don't have a resistor higher than 56ohm on 6vdc (i don't know about higher voltages) you don't get that nice chirping we we we we we we we we sound you get bughhhhhhhhhhhhhhhhhhhhhhhhhh witch i don't think is good for that buzzer ether
but very good i'm using this for my security system in my room

I put one of these under my dash in parallel with the standard siren. Borders on painful, the idea being a perp might want to reconsider spending time trying to slide hammer the lock out or whatever.

I'm going to add a second unit, add 3db. Also might replace the standard siren with a couple of these since it sounds like everyone elses. Also, I don't depend on the siren so much as the two way remote.