Piezo help

[geminni]

Planet10 gave me a link a couple of posts up.The last paragraph might as well be chinese to me.Could somebody draw that out for me.I am confused on series caps and shunts.I thought shunt was series and series cap was parallel.HELP,I'm so lost.here it is.............Looking from the amp, first the series crossover cap, say 4 uF, then the 22 ohm shunt from hot to ground, then a series cap of about 0.15 uF for 6 dB attenuation, and then a series resistor of about 30-50 ohms to tame the very top end, then the piezo itself.

Here is how i made it couple months ago.

 

[Inductor]

Piezo is about 94 dB (x2units). Please give adequate information of the woofer specs you plan to use to the forum and xover frequency if you know.

 

[shawn1972]

Geminni and rest thanks for the help.That diagram is exactly what I was looking for.I have 12 Vifa mids and I have decided to go with 12 instead of 24 piezo's. i will run each 1 parallel off woofer to that diagram crossover.Geminn,How do they sound?

 

[geminni]

Well, my piezos are crossed somewhere around 6khz because they work in 3-way PA speaker. I used them here because mid horn lacks in high frequencies. Sound is ok for PA but for home listening i don't like them.
Other thing is that mine are some cheap chinese piezos, 3 per box, and all 6 have different spl!!

Some years ago i had one cheap and one Motorola piezo conected parallel, per box. After just 1 party both Motorolas have survived and both cheap one blew out! And i remember that Motorlas had much better sound.

Sound of your piezos can be different so it is up to you to decide what to do. Do some experiments with crossover so you can learn what each element does. And then you can find the sound you like.