Taming piezos?

[bogie]

I'm thinking of using a bunch of the little 2x5 dealies... Figuring on a highish xover point, active xover, with active EQ available... Object is SPL for a few dj'd parties. Plan B is a row of neos... Mids are going to be Beta 8 lines, and I'm looking at a pair of Fitz's Tuba 36 slims for the low end.

I know that Fitzmaurice uses piezos in his PA stuff... what sorta crossover magic do they mess with?

[Paul O]

> I know that Fitzmaurice uses piezos in his
> PA stuff... what sorta crossover magic do
> they mess with?

None!! and apparently "they sound great". I have heard plenty of piezos over the years, including some large arrays, and still they sound like.. a whole bunch of piezos!!! There's no getting away from that distinctive sound. I prefer conventional bullets.. the 270-055 driver works much better.

[samadams]

He doesn't use any crossover, and doesn't use any do-dads. He uses lots of horns, vertically arrayed, with the frames between the individual horns removed so there's one continuous horn mouth from top to bottom. It works.

[envisionelec]

> I'm thinking of using a bunch of the little
> 2x5 dealies... Figuring on a highish xover
> point, active xover, with active EQ
> available... Object is SPL for a few dj'd
> parties. Plan B is a row of neos... Mids are
> going to be Beta 8 lines, and I'm looking at
> a pair of Fitz's Tuba 36 slims for the low
> end.

> I know that Fitzmaurice uses piezos in his
> PA stuff... what sorta crossover magic do
> they mess with?

I would be cautious about running an array of piezos without some sort of compensation. The load is (almost) purely capacitive which causes problems for many amplifiers. I can't recall the exact value, but I think a 20 ohm 5 or 10W series resistor with the array will help keep that current waveform from lagging too much.

[matg]

[wg_ski]

> He doesn't use any crossover, and doesn't
> use any do-dads. He uses lots of horns,
> vertically arrayed, with the frames between
> the individual horns removed so there's one
> continuous horn mouth from top to bottom. It
> works.

Do THAT with real compression drivers and you'll be getting somewhere.

[samadams]

> Do THAT with real compression drivers and
> you'll be getting somewhere.
Maybe. But the $26 piezo arrays in my DR250s sound better than the $450 JBL 2426/2370 in the cabs they replaced.

[Paul O]

> Maybe. But the $26 piezo arrays in my DR250s
> sound better than the $450 JBL 2426/2370 in
> the cabs they replaced.

Well..I can't say they don't because I'm not wearing your ears. :)) But consider that what you quantify as "better" may have more to do with the way the different drivers are employed.
The piezos in the DR's are only contributing significant output above 3.5khz to 5khz, while the 2426/2370 combo was likely operating down to the 800-1000hz area. So it's not really an apples to apples comparison. My experience with trading piezos for compression drivers where the operating range is identical, is that the compression drivers offer clearer more detailed sound every time. The lower that range extends the more pronounced the difference.

[wg_ski]

> Maybe. But the $26 piezo arrays in my DR250s
> sound better than the $450 JBL 2426/2370 in
> the cabs they replaced.
Compare that piezo array to a stack of D210's with the horn flares cut so they fit together like one big horn. One big horn that doesn't have the roll off problems of a single large format horn. Then you'll be pitching the piezos, and wondering where you're going to get the money for the other side :-).

And most all 1" or 2" drivers on *large format* horn flares suffer from roll off above 5kHz or so unless the horn was designed to beam with increasing frequency. Used without any EQ on a large format CD horn, you get your head ripped off with midrange. Ouch.