I have a bunch of cheap piezoelectric tweeters which I got a long time ago, from Radio Shack I think.
Are these devices normally designed as "BURNOUT-proof"?
Do they require a capacitor connected in series to filter out low frequencies, when connected in parallel across a regular full range speaker?[/QUO
Hi Andy,
Welcome to the Forum. Nothing is really burnout proof - even your cheap Radio Shack piezo tweeters. I always found these to be a bit Harsh sounding but there are methods around to mitigate that.
The following is from this OEM Site:
http://www.piezosource.com/
The piezo tweeter does not require a crossover network. Since the tweeter is capacitive in nature, it rejects low-frequency power. However, if the mid-range is still operating at the turn-on of the tweeter (4 kHz in the case of the Super Horn), a harshness may be heard in the total system. This disturbance in the crossover region can be minimized by the addition of an R-C filter (Figure 10) tuned to attenuate the turn-on peak, rolling off the mid-range a little earlier. If a conventional crossover network is to be used, the tweeter must be made to look "resistive" in order to work with the crossover. This can be done by wiring an 8 ohm resistor across the piezo tweeter. It should be noted, however, that the power efficiency benefits are now lost since the piezo tweeter will look more like an 8 ohm dynamic unit electrically. It will, however, allow the use of conventional crossover technology. If a variable level attenuation is desired, an L-Pad can be used.
There is some good information there even though it's based on Motorola's design, in general it should apply to your units.
