question about piezos...

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Hi I was wondering if someone could help me figure out which resistor to put on this piezo tweeter that I am running with an 8 in dayton classic woofer.

This is the woofer: Dayton Audio DC200-8 8" Classic Woofer 295-310


The piezo: Goldwood GT-400CD Bullet Piezo Horn Driver 270-069

I put a 4.7 on the piezo and it soundfine but im not sure if im getting the midrange frequencies. What would be a good resisitor to use in this setup? and how do the resistors affect piezos?

thanks
 
Piezo tweeters are capacitive (in this case about 300nF), so it makes sense to me to use a crossover something like this:
 

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Aren't piezos like supertweeter ? Or at least, in hi-fi I think they should be used like supertw ...
There's a design that uses a Ciare pt 383 as a regular tweeter and a Motorola
piezo, used above 10 KHz ( well, the Ciare tw is not 'regular', being mid-hi sensitivity and having a big dome ...)

So, the midrange...:rolleyes:
 
Using just a single resistor in series with the tweeter doesn't help the tweeter at all, it just protects the amp from possible instability at ultrasonic frequencies. You can use a piezo tweeter like that, but it's better to use a proper crossover as shown above. That keeps the bass and most of the midrange out of the piezo, thereby improving power handling and reducing distortion.
 
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