Fullrangedriver Forum

A super tweeter, that is.

I had an unused automotive speaker box that I had aquired with the purchase of a previous vehicle , so I snatched the Piezo tweeters from it .

I couldn't leave them stock, and I'm glad I didn't ! They were different drivers , although they appeared to be the same from the external view.

The compression "star" of each driver was slightly different from one another , and one of them had considerable plastic flashing (excess from the mold) and blobs of hot glue blocking the openings of the compression "star" . On that same driver, the manufacturer had used hot glue to attach the Piezo element to the paper cone ! I carefully seperated it with an X-Acto and reattached the Piezo element to the paper cone with some superglue after a careful cleaning.

Next step was to remove the rear chamber from behind the paper element. You know , the plastic "cup" that the terminals are molded into ? So I pulled out my Dremel and a cutoff wheel and basically removed the whole rear "cup" except for two small tabs to hold the terminals. No more nasty reflections radiating directly back into the paper element ! Nice dipolar output to match my 'Rads .

I reused the 17 ohms of resistors they had from the factory ( they were originally a 10 ohm and a 7 ohm in series, then series with the driver ) , but wired them across the terminals and used a .47 Poly cap for a X-over . If I calculated correctly , this should be about 6db down at 10khz.

I've only listened to one album thus far (Mark Knopfler), but am impressed with the extra "air" and the obvious extension in the highs. No real misgivings so far. I'll have to try some more and different styles of music.

At this point, I will say "Success !"  Thanks for the idea , all those that have used and posted about the use of Piezo super tweeters !

I'll try to get some pics up soon. Here's a link to a similar driver : http://www.adelcom.net/MOTOROLA_ksn1038a.htm



Gotta go chow and listen some more. I'll post more listening impressions and some pics soon.

....................................Blake