Piezos from monday morning shift...

[AntonZ]

MPT-016

Anton, could you please tell me where you got those? Planning on building 4 DR250's

Try Sabbelbacke. He's located in Germany.

The MPT-016 are from Monacor. I don't know if it's an OEM.

Yep, PM member Sabbelbacke (Reiner). He got me both the cheap and the good tweeters. The tweeters may take some time, so better order in time. He also got me some Eminence drivers and cabinet hardware for good prices, too.

I didn't know these piezo's were from Monacor, thanks for the info.

[thijs666]

Try Sabbelbacke. He's located in Germany.
The MPT-016 are from Monacor. I don't know if it's an OEM.

Yep, PM member Sabbelbacke (Reiner). He got me both the cheap and the good tweeters. The tweeters may take some time, so better order in time. He also got me some Eminence drivers and cabinet hardware for good prices, too.
I didn't know these piezo's were from Monacor, thanks for the info.

Yep, thanks for the info

[slyslam]

Hey!!!
That's exactly what I found with my piezo tweeter. For the ones who remember, I mentionned that a bank of 6 of my #SH305 ( same as right) outpassed significantly the other one with #1016.
Happy that I'm not crazy!!!!

Double in price but also double in quality!!!!

[Tom]

Pyle 1016s are made by Pyramid as model PMBTW12

http://www.pyramidcaraudio.com/itempage ... el=PMBTW12

They have the ridge shown in the picture.

They sell for less than a dollar at allaudioexpo.com.

I BOUGHT A BULK PACK OF 125!

My DR250s sound fine to me, but now I'm freakin' out after reading this post!

[Tom]

Here are some pics of the two models of piezo's that I got. Model with the red dot is good quality

Your photo of the terminal-side view looks like the 1016 I use.

These photos look swapped to me. Are the "cheap piezo" terminals aligned with the short dimension of the tweeter, or rotated by 90 degrees, aligning with the longer dimension?

I would like to settle this supplier issue for all going forward.

[AntonZ]

Here are some pics of the two models of piezo's that I got. Model with the red dot is good quality

Your photo of the terminal-side view looks like the 1016 I use.

These photos look swapped to me. Are the "cheap piezo" terminals aligned with the short dimension of the tweeter, or rotated by 90 degrees, aligning with the longer dimension?

I would like to settle this supplier issue for all going forward.

I checked once again, on all my pics the ones with the red dot are the better quality model. Not swapped. The cheap model is slightly larger.

Can't be 100% sure about the location of the terminals on the cheap model. You can see the three screws are missing. All I had left from the cheap ones after practicing and using some in a bass cab was in parts. That's because I took them apart if they didn't work well, to check for glue on cone. There was no need to take any of the good ones apart, so the model with the red dot has the terminals as they came from the factory.

Please note that this is not conclusive about each and every 1016-like piezo model out there. There may very well be more than two sources, so the model you have may be ok while different from my good piezo's.

[N.Webber]

Ok,
(Well, actually not so…)

I have replaced the damaged drivers I mentioned in my initial post and checked all the piezos for 'good' (more on that later…)
and equal output and matching polarity and proceeded to saw and glue the arrays.

As the second array was curing, I re-assembled the drivers of the first array and wired them (correctly ).
I then connected them to some music just to hear how the array sounded.
The array sounded real bad! It had this prominent peak at around 4 kHz but everything above that was noticeably weaker

I decided to conduct a basic bench test to compare the response of one of these piezos to a known good one
(a genuine Motorola I had laying around).
I set up the two piezos adjacent to each other in front of an SPL meter and fed them alternatively
through an A-B switch with the same sine signal.

I monitored the output of both at different frequencies from 2 kHz and up.
I noticed the 'No Brand' piezo was about 3 -6 dB behind the Motorola up to around 4 kHz
(the closest the NB got to the Mot. was at 4.5 kHz with just 1.5 dB difference)
From there the NB simply dived and run in the range of 10 up to 30 dB (!! At 10 kHz) lower then the Mot.
The Mot. 'finally' started rolling off at 15 kHz maintaining ±2 dB along its working range.

I was disappointed, though I hadn't expected too much from back street China piezos, I just didn't think they would be SO bad

These NB piezos are definitely no good for (any) serious PA cab even when arrayed. They are junk.
I would recommend to anyone looking for piezos to avoid this 'brand' if possible (before purchasing…)

…And to conduct a response test BEFORE sawing and gluing

This is how they look up close:



As for my 290/280 'piezo project', I am back at square one, looking for decent 1016 piezos…

[Frankenspeakers]

Ok,
(Well, actually not so…)

OH NOOOOO, MiSTER BILLLLLLL

Say it ain't so,Joe!

I have a small pile of PE piezos I got July 06. They look like Anton's 'good' ones... but they also look a lot like the bad ones from Mr. Webber (except that the oval "tag spot" on his appears to be further off center than on mine & the texture seems a little more pronounced ... Anton's seem to not have a tag spot, and less texture also. The 'A' side of the mold looks like it has a few more marks on the tooling around the ejector pin marks... I'm hoping fervently that Mr. Webber didn't get those from PE! Pleeeeeze...

These seem to be made in three pieces: the horn, the throat piece, and the back (with the element attached) ayone have trouble with the PE piezos?

[Bill Fitzmaurice]

At this point all we can say for sure is that the 1016's from PE in the US, and CPC Farnell in the UK are OK.

[AntonZ]

OH NOOOOO, MiSTER BILLLLLLL

Say it ain't so,Joe!

Mine are also three pieces. At first glance, they look identical to Nick's bad batch. The only distinct difference I can spot is the location of the + and - marks. Mine have the marks more towards the center, the marks on Nick's piezo's are more towards the edge. So although the resemblance is striking, they do appear to me to come from different sources.

Try like 20 of yours on the headphone output of a small transistor radio tuned between stations. If one in every 5 or 6 sounds distinctly different from the rest, you may have a nice pile of crap to practice cut&glue beyond perfection If they all sound near identical, you most probably have good piezo's.

[fender3x]

I have been studying this pic... I have some PSN1167s (the dreaded Pyle tweeters) and some Goldwood 1005s. Looking at the backs, the Pyle tweeters look pretty much like the bottom tweeter in this pic. The GW tweeters have "tag oval" too...but it's larger than the one on the Pyle... so the GW tweeters don't look exactly like the ones on the "red dot" tweeters either... All that means is that they are not identical to the GWs, but I mention it here for what it's worth.

I am using the Pyle horns because they fit better in my cab than the 1005s...due to a (long story) mistake I made in port placement. What I've been doing is taking apart the Pyles (a process that requires soaking in mineral spirits due to the excess glue used in the Pyles). I clean out the glue (with toothpics and mineral spirits) and throw away the Pyle element, replacing it with a GW 1005 element.

Not endorsing the use of 1167s or 1005s here. The only reason that I mention this is that it looks like you may have glued up your tweeter array already. if you can get some GW tweeters (or the UK equivalent) you can swap out your bad elements and put good ones in. It's kind of a pain to clean the horn elements if you have the excess glue problem, but might be easier than remaking the array.

If you haven't done the glue up yet...please ignore this post and I'll go back to sleep....

[gdougherty]

OH NOOOOO, MiSTER BILLLLLLL

Say it ain't so,Joe!

Mine are also three pieces. At first glance, they look identical to Nick's bad batch. The only distinct difference I can spot is the location of the + and - marks. Mine have the marks more towards the center, the marks on Nick's piezo's are more towards the edge. So although the resemblance is striking, they do appear to me to come from different sources.

Try like 20 of yours on the headphone output of a small transistor radio tuned between stations. If one in every 5 or 6 sounds distinctly different from the rest, you may have a nice pile of crap to practice cut&glue beyond perfection If they all sound near identical, you most probably have good piezo's.

Would be interested in other comments regarding Anton's observation here. My purchases from PE and bltsound both fall into the "nice pile of crap" rule of thumb he suggests here.

[David Carter]

Mine are also three pieces. At first glance, they look identical to Nick's bad batch. The only distinct difference I can spot is the location of the + and - marks. Mine have the marks more towards the center, the marks on Nick's piezo's are more towards the edge. So although the resemblance is striking, they do appear to me to come from different sources.

Try like 20 of yours on the headphone output of a small transistor radio tuned between stations. If one in every 5 or 6 sounds distinctly different from the rest, you may have a nice pile of crap to practice cut&glue beyond perfection If they all sound near identical, you most probably have good piezo's.

Would be interested in other comments regarding Anton's observation here. My purchases from PE and bltsound both fall into the "nice pile of crap" rule of thumb he suggests here.

I am also very interested. I purchased 48 peizos from Lawrence Langford (they were delivered in a PE box) for two DR250 melded arrays. I did the "listening to static" test with white noise, and found 8 out of the bunch that sounded lower in tone. I used those to practice cutting, and I made two melded arrays with the rest. I don't have any SPL meters or RTA gear for testing--just my ears (which are very much of the novice variety). I'm very concerned about whether or not I'm wasting my using these arrays.

[Bill Fitzmaurice]

If you're using PE piezos, which are what both Lawrence and Leland ship too, your results will be the same as mine.

[slyslam]

the only difference I noticed on mine is the location of the front diffusor.
The better one align horizontaly (same as red spot )and the cheap one vertically.