BillFitzmaurice.info

Hi everyone,
Not sure where the best place to post this project type.

I am currently working on building an LRAD/Alarm/Ultrasonic Speaker array to deal with daily homeless tweeker loser drug addicts tresspassing, vandalizing, stealing on my business property.

Link to what Im working on https://www.amazing1.com/products/phaso ... tubes.html

Video of the system working is shown at bottom of the page link.

The transducers/tweeters are here; https://www.amazing1.com/products/trans ... ators.html

They look to be a typical cheap piezo tweeter in the 10-40khz range.

I have had the pleasure of renting one of these to verify operation and it is great for the size and functional. Per advertised its fantastically irritating. These can also be built from plans which I am doing.

Specifics and requirements are:
1. I want to supersize this. I plan on using 20 of the transducers. I will be building 4 of these units in total each with 20 transducers.
2. I need or prefer to get the most powerful, high quslity transducers in the 10-40khz range. This is where I need some specific help as Im not sure what will work that will put out as much db levels as possible. I have seen the super tweeters (titanium). However not sure specifically what high quality transducer/tweeters I can use?
3. Im on a 22 acre parcel. So there wont be any issues with complaints or city or anything else. Not that I really care... I want ear splitting, irritating, painful, loud as physically possible.

I have gathered all the components to build this... Nust need a line on quality transducers. I will start another thread in the build section when I start.
These losers have destroyed my business, taken everything that took...in some cases 30 years to aquire or build by hand. So things are a changen for these #holes.

Thanks all in advance for your help.
Best
J

Look familiar?

https://www.speakerhardware.com/goldwood-piezo1005.php

There's nothing out of the ordinary at the site you linked, other than their exorbitant pricing.

Any thoughts on better quality tweeters that can handle more power?

All piezos have roughly the same capacity. Being capacitive loads they're voltage limited, not power, at about 25v. To get higher output our piezo arrays are wired series/parallel, for a 50v limit. That, along with the proprietary high pass filter we use, allows them to keep up with a 450w woofer in a DR280. We use 1016 piezos in arrays because the 1016 horn shape is better suited to the task. The drive element of 1016 and 1005 is the same.

Thanks Bill, thankfully I purchased ALL your speaker designs a few years back. I did a bit of research and discovered the lrad type arrays is a basic 2 inch compression driver almost identical to a DS18 PRO-D1. Its a 1000 watt driver? Or so stated? Ideally I need to build something that I can speak through as well as deliver irritating siren noise... Which I already have a clean wav file siren sound. I have 10 100 watt pa outdoor horns (public address type) Which are not able to be heard clearly or work well as an alarm/siren. Im not sure if these are a reasonable typical sturdy driver? Or if there is something comparable for better price?

You don't get 1000w drivers for $69.95. For that matter there's no such thing as a 1000w compression driver. Compression drivers are rated according to the full system power rating, with a given crossover frequency and slope. In a typical 1000w speaker system the HF element might actually handle 200w max. Go to the DS18 site, it's actually a 150w driver. It claims to go to 18.5kHz but their own chart shows it rolling off at 7kHz.

Hi. For humans, ear piercing frequencies are generally in the 1500-7000 Hz range. Personally I tend to find 3000 and 6000 particularly rough. Of course, playing these frequencies extremely loud at night is going to disturb the neighbours' sleep.
Above 10kHz it can definitely be annoying, but unless you are a dog unlikely to be painful. By the time you get to 15kHz it's annoying mostly to teenagers. 40kHz will be inaudible, though whether it can do silent hearing damage at extreme levels I am unsure of. If there are no hair cells in the cochlea that are customised to resonate to it, it's unlikely.

As for power handling, there is peak and heating limit. Pulsing a tone on and off in increments allows you to output twice as much power for the same heat. It also sounds even more annoying.

Tweeters I've found Eminence APT80 to go pretty loud, though they are more expensive but can be had for £25 or so. A load of them should make a racket - even one at close range will be uncomfortable. My Omnitop 12 use Beyma CD10fe. You could use a horn that's a quarter wave of the most ear piercing frequency as you aren't looking for smooth response here. If you have money to burn, a Danley J4 combines 64 compression drivers in phase into a conical horn. They are meant for throwing treble across a stadium.