Using piezo tweeters wisely: a "how to"

Well CRAP! I got the tweeter box out and it is a "super tweeter" just not the one you are posting about.

Do you have any info on this rocket tweeter???? (I can get better pictures to add)

Thanks,

It's not actually a compression driver - it's a mylar diaphragmed tweeter, really common design - kinda thing you can buy from Radio Shack.

In my opinion would sound nicer than a Piezo though. Often used as 'super tweeters' as they can't handle much in the lower mids.

Mike
 
It's not actually a compression driver - it's a mylar diaphragmed tweeter, really common design - kinda thing you can buy from Radio Shack.

In my opinion would sound nicer than a Piezo though. Often used as 'super tweeters' as they can't handle much in the lower mids.

Mike

Ok that makes sense. I bought them to "open up the high end" of an open baffle stack of 4" "full range" Pioneer speakers I bought from Parts Express (8 per side).

It has not been implemented yet. But one per side in a shoe box sounded "pleasant."
 
Thanks for the great info here, esp Paul. I am a Klipsch collector and have some of their 1970's PA stacks the MCM-1900. The very high cabinet is called the MTM and houses 5 piezo tweeters in a vertical stack, arrayed in a curved formation. These are the rectangular models and measure 2 5/8 x 5 3/4 overall to the outside of the mounting flange. Are these from Motorola/CTS? I need a a few replacements- are the Parts Express models the real deal or inexpensive imitations? Thanks
 
Parts express peizo's are made by goldwood. which are imitations. I have no idea how close they are to the originals.
 
Goldwood KSN1188A knock-off

Had a pair of PA cabs brought to me today for repair. They were dropped and it damaged one of the piezo drivers, breaking it's phase plug and lug post. Anyway, for those who have never seen the internals of one of these, here ya go. Note the paper cone with the piezo element attached, the waveguide and backchamber, that are sealed when bolted together. There's a 4.7uF cap and an inductor that surrounds the waveguide. You usually see small lamps in these for clip protection, but these (for whatever reason) don't have that. I also included a side view of the undamaged driver. Going to replace both with CTS Powerlines.

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The information in this thread has given me the confidence to add some tweeters to my guitar cabinets, through which I run a Roland VG-99 and GR-33.

My question is this:

If I use the L-pad / crossover circuit (as illustratred by Paul C) and I wire it in parallel with a single 8-ohm speaker, will the load on the amp drop to 4-ohms or does adding the tweeter in this fashion have no effect on the load?

cheers.
 
The information in this thread has given me the confidence to add some tweeters to my guitar cabinets, through which I run a Roland VG-99 and GR-33.

My question is this:

If I use the L-pad / crossover circuit (as illustratred by Paul C) and I wire it in parallel with a single 8-ohm speaker, will the load on the amp drop to 4-ohms or does adding the tweeter in this fashion have no effect on the load?

cheers.

Is this for acoustic guitar, or electric? I've used piezos successfully with acoustic amps, but always hated the sound of them with electric, even when properly installed. You might want to rig it up as a temp/test setup before putting too much work in it (or modding the cabinets).

YMMV-

je
 
I'm adding tweeters primarily for acoustic sounds and guitar synth, but will be playing electric through it, as well. The cabs will be powered by a clean, solid state amp. The VG-99 provides amp modelling and has output settings for line/phones, which makes it sound very good through a full-range system. I'm hoping that using an L-pad will enable me to dial-in just enough high-end to give a good balance for everything.

My cabs are Rocktron S112's (single 12" in ported trapezoid)...I have 4. Planning to add tweeters to only two of them and if the sound is too harsh for the electric sounds, I can put them on a separate amp and route my signals accordingly.

I'm just a little confused about how to wire the tweeters. I think I'll start by just using an L-pad with a series resistor in front of it (I was told this is the recommendation from the Motorola specs for the 1165's...to protect the L-pad). Hopefully, that will sound good...if not, I'll have to start experimenting with a crossover.

If I add a crossover, do I have to be concerned about the load on the amp? For example: the woofer (8-ohm) will be wide-open with a top-end freq. response of about 5K. If I crossover the tweeter at, say, 4K, in parallel with the woofer, will it put any extra load on the amp? What if the crossover point is lower for the tweeter (still full-range on woofer)?
 
Piezo Tweeter Application Note

I haven't but skimmed a couple posts in this thread, but I believe the following link - also seen at Parts Express - is considered about as definitive as any by at least one pro designer (Bill Fitzmaurice) who has used piezo arrays in some of his designs:

Piezo Tweeter Application Note
 
Can anyone help? piezo again u probly thnking!
how many piezo tweeters KSN1001A
can i hook up per channel on a power amp? safely!
just got hold of a cab with 14 in it and there wired in parallell.and had a resister on every tweeter.can i use all 14 on one channel?
so watt the differenece in series ie output? sound? ohms? do thay need resisters? ect ect
localy pa man at shop said u can wire as many as u like! cus no impedance but surly not?
hope someone can help
many thnks!!
 
Waveguides

Paul C,
You have me convinced to go with piezo tweeters. I have a question about the horns though. How do you feel about waveguides, especially 12" waveguides for over 5kHz?
My present OB started out with a 12" full range on top augmented with a 12" woofer& a 15" sub. I found that it's better with just the fullrange & the sub.
It occured to me that I could use a 12" waveguide.
Frank
 
Paul C convinced me as well to use a mid piexo driver on a EV build a while back. It was very impressive to say the least! I now consider Piezo in a new light- the good ones that is, not the knock off that are around every corner. The driver was very neutral sounding- not at all "hony" ot brittle soundng.
DC
 
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