Can I use Pizeo Tweeters, or????

[olds...@tubes.com]

I have an older pair of Fisher 3 Way Speakers. They are good speakers,
except on of the tweeters is blown and sounds horrid. Fisher is out of
business, so I cant buy an original replacement tweeter.

I am looking on speaker websites and ebay, trying to find a replacement.

I realize that I will need to replace the tweeter in BOTH speaker
cabinets so they match.

Obviously I need something that will fit the hole in the cabinet. I also
need to match the impedense (8 ohm), and get tweeters rated at the same
of higher power rating for these cabinets, (each cabinet is rated at
120W).

I have heard that the Pizeo tweeters are good, and can handle a lot of
power, plus they are fairly inexpensive.

However, I may be wrong, but I recall hearing something years ago, that
the Pizeo speakers should not be connected to a crossover system, and
need to be run direct. (I do not know if this is correct).

These cabinets DO have a crossover.

Of the non-pizeo types, I am seeing a lot of terms that I dont fully
understand. There are "Bullet Horn Tweeters", "Titanium tweeters",
"Fluid Enhanced Voice Coil", and more....

Some have huge magnets and are rated at extreme wattages, like 1500W
(but I'm sure that highly exaggerated, and not true or RMS power).

Some also list the frequency range. I dont really know what the
crossover points are, and doubt I can really find that out.

My question is this: Do I need to be real critical, or will most any
tweeter work? I will avoid the Pizeo types if they wont perform properly
with the crossover.

Do the "Bullet" types perform better, or is that just a decorative
thing? What is Titanium? Is that the magnet type, or what?

I do intend to buy something that can handle power, since these speakers
do get driven hard at times.

One other thing, are there any brands to avoid, and any brands that are
considered to be the best? I'm seeing a lot of brands, but the brands I
see most are Pyle, Pyramid, Orien, Pioneer, AudioQuest and Alpine. (The
Alpine seem to all be for cars, but it probably dont matter what they
are used for).

Any tips or suggestions?

Thanks in advance.

[pf...@aol.com]

On Wednesday, May 3, 2017 at 4:36:37 PM UTC-4, olds...@tubes.com wrote:
> I have an older pair of Fisher 3 Way Speakers. They are good speakers,

On Wednesday, May 3, 2017 at 4:36:37 PM UTC-4, olds...@tubes.com wrote:

> I have an older pair of Fisher 3 Way Speakers. They are good speakers.

These two statements are mutually contradictory.

With that in mind, seriously:

a) any tweeter that will fit will be remarkably better than what started there back in the day.
b) Rebuild the crossover (if any), at least replace *all* the capacitors. Use screened non-polarized caps of the correct value. No guessing.
c) Piezo speakers are, in a single word, manure.

So, look on-line at any of several sources (one attached).

https://www.parts-express.com/cat/tweeters/17

$10 or so should be your upper, upper limit per each, whatever fits and is approximately the same impedance as the existing unit - which, unless it is open can be measured. When in doubt, use nominal 4-ohms.

If it fits, this one will do fine:

https://www.parts-express.com/grs-1td1-8-1-dome-tweeter-8-ohm--292-462

You need to understand how speakers are rated. If you were to run a steady-state 120 watts of power into those speakers for say.... 20 minutes at a reasonable frequency mix, they would be a slagged mess. At a specific frequency, a slagged mess in 3 minutes or less. Music does not play that way.

I have a pair of speakers "rated" at 125 watts, but they are extremely inefficient. 1 watt makes 83 dB at 1 meter. I feed it with a 225-watt amplifier that will make a peak (without clipping) of about 1,000 watts for one (1) second.

Which means that if my *average* volume is 83 dB, I will be able to handle a 30 dB Peak-to-Average signal, without clipping, as long as the peaks do not exceed 1 second (most really do not). Would I be worried about pumping 1,000 watts into these speakers? Not hardly. And were the signal to be longer than 1 second, the safety circuits would kick in and shut it all down anyway. But in 40 years I have not blown a speaker (due to volume, anyway) yet.

Would I be comfortable running either of my brute-force amps into those Fishers? No, I would not. Into my little AR4xs? Every day.

Peter Wieck
Melrose Park, PA

[amdx]

On 5/3/2017 3:56 PM, pf...@aol.com wrote:
> On Wednesday, May 3, 2017 at 4:36:37 PM UTC-4, olds...@tubes.com wrote:
>
>> I have an older pair of Fisher 3 Way Speakers. They are good speakers.
>

> These two statements are mutually contradictory.

You just couldn't restrain yourself could you? :-)

I used to work in a consumer electronics repair shop.
Authorized repair for about 100 brands, but we made a
lot of money on Fisher products.

Mikek

[ohg...@gmail.com]

I can't count how many of those Darlington STK ICs I changed in the 80s. As bad as they were, they were nowhere near as bad as the Pioneer amps with the "suicide" line to "protect" the speakers. The good thing is that they used a fan in the tunnel to conveniently let the smoke out the back.

[Clifford Heath]

On 04/05/17 05:35, olds...@tubes.com wrote:
>
> I have an older pair of Fisher 3 Way Speakers. They are good speakers,
> except on of the tweeters is blown and sounds horrid. Fisher is out of
> business, so I cant buy an original replacement tweeter.
>
> I am looking on speaker websites and ebay, trying to find a replacement.
>
> I realize that I will need to replace the tweeter in BOTH speaker
> cabinets so they match.
>
> Obviously I need something that will fit the hole in the cabinet. I also
> need to match the impedense (8 ohm), and get tweeters rated at the same
> of higher power rating for these cabinets, (each cabinet is rated at
> 120W).
>
> I have heard that the Pizeo tweeters are good, and can handle a lot of
> power, plus they are fairly inexpensive.

Two out of three ain't bad. But piezo tweeters are.
They have a vast array of mechanical resonant modes
so you just can't get a flat response. Throw them in
the trash where they belong and buy modern Kevlar
domes or something, depending how much you care.

[mike]

On 5/3/2017 12:35 PM, olds...@tubes.com wrote:
>
> I have an older pair of Fisher 3 Way Speakers. They are good speakers,
> except on of the tweeters is blown and sounds horrid. Fisher is out of
> business, so I cant buy an original replacement tweeter.
>
> I am looking on speaker websites and ebay, trying to find a replacement.
>
> I realize that I will need to replace the tweeter in BOTH speaker
> cabinets so they match.
>
> Obviously I need something that will fit the hole in the cabinet. I also
> need to match the impedense (8 ohm), and get tweeters rated at the same
> of higher power rating for these cabinets, (each cabinet is rated at
> 120W).
>
> I have heard that the Pizeo tweeters are good, and can handle a lot of
> power, plus they are fairly inexpensive.
>
> However, I may be wrong, but I recall hearing something years ago, that
> the Pizeo speakers should not be connected to a crossover system, and
> need to be run direct. (I do not know if this is correct).
>
> These cabinets DO have a crossover.
>
> Of the non-pizeo types, I am seeing a lot of terms that I dont fully
> understand. There are "Bullet Horn Tweeters", "Titanium tweeters",
> "Fluid Enhanced Voice Coil", and more....
>
> Some have huge magnets and are rated at extreme wattages, like 1500W
> (but I'm sure that highly exaggerated, and not true or RMS power).
>
> Some also list the frequency range. I dont really know what the
> crossover points are, and doubt I can really find that out.

If you can read or measure the component values, you can
calculate it.
There are spectrum analyzer apps for Android. Connect and disconnect
the tweeter on the good one and see how the shape of the signal changes.
Would be more precise with another phone and a signal or white noise
generator to drive the amp.

>
> My question is this: Do I need to be real critical, or will most any
> tweeter work? I will avoid the Pizeo types if they wont perform properly
> with the crossover.
>
> Do the "Bullet" types perform better, or is that just a decorative
> thing? What is Titanium? Is that the magnet type, or what?
>
> I do intend to buy something that can handle power, since these speakers
> do get driven hard at times.
>
> One other thing, are there any brands to avoid, and any brands that are
> considered to be the best? I'm seeing a lot of brands, but the brands I
> see most are Pyle, Pyramid, Orien, Pioneer, AudioQuest and Alpine. (The
> Alpine seem to all be for cars, but it probably dont matter what they
> are used for).
>
> Any tips or suggestions?
>
> Thanks in advance.

There are a huge number of issues.
There should be a lot of overlap in the frequency response of your
woofers and tweeters, so the precise crossover may not matter much.
BUT, the sensitivity of the tweeter needs to match.


I bought a subwoofer with built-in crossover at a garage sale.
It's about the size of a coffee table. Puts out a LOT of bass.
Problem is that I never found any speakers that would work with it.
Sure, there's bass, but the response is not flat because the
sensitivity of the speakers doesn't match the design of the crossover.
There's a big step in the frequency response plot.

Still works as a coffee table.
And the Klipsch Korner Horns still work as speakers.
I don't use 'em, should sell 'em.

[olds...@tubes.com]

I recall back in the 80s I had a woman friend with a Fisher solid state
receiver. She had spent a lot of money getting that thing repaired when
she blew out the audio output ICs. A few months later she blew them
again. When she learned that I had previously worked on electronics, she
wanted me to fix it. At the time I did not have much left for test gear,
and I hated working on IC devices. But as a friend, I tried. Those ICs
were blown, along with some other diodes and stuff. I could not find
replacements for those ICs anyhow. I talked her into buying a separate
power amp. I cut the power to that output board, and she just used the
Fisher receiver as a tuner/preamp, and fed the sound to the new power
amp. I was NOT impressed by that receiver.

I never owned any Fisher tube gear, but I heard it was built well.
That's all I know about that, except it sells for big $$$ now.

As far as my Fisher speakers, they have decent 15" woofers, and sounded
good till I connected up my new 600W (300 per channel) commercial power
amp. I'm only running it at about 1/3 full power, and the woofers sound
great. The mids are ok too, but I blew that tweeter almost instantly.

However, I just learned why. I removed both tweeters and found that the
one that blew is a Radio Shack replacement rated at 25W. I guess there
is no need to explain this further, since I'm pumping at least 100W into
them and that was a 25W speaker....

[Trevor Wilson]

On 4/05/2017 5:35 AM, olds...@tubes.com wrote:
>
> I have an older pair of Fisher 3 Way Speakers. They are good speakers,
> except on of the tweeters is blown and sounds horrid. Fisher is out of
> business, so I cant buy an original replacement tweeter.
>
> I am looking on speaker websites and ebay, trying to find a replacement.
>
> I realize that I will need to replace the tweeter in BOTH speaker
> cabinets so they match.
>
> Obviously I need something that will fit the hole in the cabinet. I also
> need to match the impedense (8 ohm), and get tweeters rated at the same
> of higher power rating for these cabinets, (each cabinet is rated at
> 120W).
>
> I have heard that the Pizeo tweeters are good, and can handle a lot of
> power, plus they are fairly inexpensive.

**Nope. They're shit. Look at how the things are built. They use levers
and pivots and all manner of bits and pieces. Tweeters should be simple.
Voice coil, magnet and a dome or a cone. That's all you need. More
power? Find one that employs ferro-fluid cooling.

>
> However, I may be wrong, but I recall hearing something years ago, that
> the Pizeo speakers should not be connected to a crossover system, and
> need to be run direct. (I do not know if this is correct).

**Incorrect. Just parallel an 8 Ohm, 10 Watt resistor with the piezo
'voice coil' and the crossover will operate (more or less) correctly.
Contrary to a lot of common-knowledge, piezos should always be used with
some kind of crossover.

>
> These cabinets DO have a crossover.
>
> Of the non-pizeo types, I am seeing a lot of terms that I dont fully
> understand. There are "Bullet Horn Tweeters", "Titanium tweeters",
> "Fluid Enhanced Voice Coil", and more....
>
> Some have huge magnets and are rated at extreme wattages, like 1500W
> (but I'm sure that highly exaggerated, and not true or RMS power).

**Of course. Just use your noodle. A REALLY efficient tweeter is about
10% efficient. IOW: 90% of the input power is converted into heat. Think
any tweeter can dissipate more than 100 Watts?

Correct. They cannot. Most tweeters can deal with between 5 and 30 Watts
of continuous power (there is no such thing as 'RMS power'). After that
the voice coil fails.

>
> Some also list the frequency range. I dont really know what the
> crossover points are, and doubt I can really find that out.
>
> My question is this: Do I need to be real critical, or will most any
> tweeter work? I will avoid the Pizeo types if they wont perform properly
> with the crossover.
>
> Do the "Bullet" types perform better, or is that just a decorative
> thing? What is Titanium? Is that the magnet type, or what?

**'Bullet' types drivers tend to be more efficient. Not necessarily
better. Titanium refers to the cone/dome material. Modern titanium
drivers are pretty good. But so are modern plastic ones.

>
> I do intend to buy something that can handle power, since these speakers
> do get driven hard at times.

**Find a driver that uses ferro-fluid cooling and/or one that is
efficient. That way you can pad it back.

>
> One other thing, are there any brands to avoid, and any brands that are
> considered to be the best? I'm seeing a lot of brands, but the brands I
> see most are Pyle, Pyramid, Orien, Pioneer, AudioQuest and Alpine. (The
> Alpine seem to all be for cars, but it probably dont matter what they
> are used for).
>
> Any tips or suggestions?
>
> Thanks in advance.

**If you care about sound quality, avoid piezos.


--
Trevor Wilson
www.rageaudio.com.au

[Phil Allison]

Trevor Wilson wrote:

>
>
> **Incorrect. Just parallel an 8 Ohm, 10 Watt resistor with the piezo
> 'voice coil' and the crossover will operate (more or less) correctly.
> Contrary to a lot of common-knowledge, piezos should always be used with
> some kind of crossover.
>

** Having no need for a x-over was a big selling point for piezos - but it's complete bullshit

Running them without low frequency attenuation is the MAIN cause of burn outs - due to BASS frequencies exceeding the VOLTAGE limit of the piezo element.

I always added a parallel resistor and series film cap to roll of the input below 5kHz to stop that nonsense.

FYI: for use in cheap foldback boxes with Etone guitar woofers.


.... Phil

[gregz]

How old are these Fishers ?

Newer types are junk anyway. Piezo might be fine if you work out the
details as suggested. Your crossover might just be a cap plus possible
resistor.

How old are these Fishers ? Model number ?

Greg

[Adrian Caspersz]

I like the build of this Fisher pricey dual cassette deck.

https://www.youtube.com/watch?v=vmPhJj4WDOI

--
Adrian C

[tabb...@gmail.com]

Piezos are not the 'junk' some opine, far from it. But they're not top of the tree either. If you're not spending lots of $ then piezos can deliver quite good performance at relatively low price. Their shortcoming is the frequency response is a bit uneven at the top end, but domes, cones etc aren't flat either.

They can be connected where your old tweeters were if you add an 8R resistor - piezos are high impedance devices, at least in their operating range. Always put a series resistor on piezos, 10R is ok. Otherwise the amp sees a capacitive load, and some are not ok with that.

Any type of tweeter comes in good & not so good variants. If I were buying blind (or deaf) for average consumer kit I'd be more likely to get a happy result from piezos than domes.

Crossover frequency is typically 1 - 4kHz.
Tweeters only handle somewhere vaguely in the region of 20% of a speaker's input power.


NT

[pf...@aol.com]

YIKES!

OK - you are running your Altec amp at the 1/3 point. That does NOT mean you are putting 100 watts into the amp.

You really need to learn some of the basics of audio. Little steps for little feet:

a) Audio Taper Controls: https://i.stack.imgur.com/f5P1V.png

At the 1/3 point you are, perhaps, putting 10% of the amp power into the speakers - and that ONLY IF the signal is driving the amp to that level of power. So, maybe 30 watts at the absolutely loudest passage.

b) Amp output vs. signal input: Amps are rated in WPC/RMS (watts-per-channel/root-mean-square), and at a specified voltage input. Typically around 2V or so, typically at a specified frequency or group of frequencies. A preamp varies the level of input into the amp, from 0V up to as much as 13-or-more V. Consider on that and consider why.

c) I do not know what you listen to, in general. Whether it is classical (as in orchestral or 'high-brow' stuff), rock, country, Polka, or whatever. But, *most* music as recorded these days has a Peak-to-Average of 20dB at the high end, to under 10dB at the low end. Very, very few recordings even approach 30dB. So, if you are listening to well-recorded "classical" music, your P/A is 20dB AT BEST.

d) Not knowing what volume you prefer, but assume that you are averaging 1 watt into reasonably efficient speakers (those Fishers are that, at least). So, you will need no more than 100 watts of output for the very few peaks.

I doubt you have the XP10, or you would not have any issues with replacing the tweeter as that is a 2" soft dome, any decent one will do. But, as these go back to the days of Avery Fisher (1965 or so), you will be having surround-rot issues and more, which you are not reporting. So, I suspect you have one of their latter-day speakers that traded on the Fisher name, but without the quality.

[ohg...@gmail.com]

On Wednesday, May 3, 2017 at 7:56:36 PM UTC-4, olds...@tubes.com wrote:

>
> I never owned any Fisher tube gear, but I heard it was built well.
> That's all I know about that, except it sells for big $$$ now.
>

I have a small collection of vintage tube hifi, mostly Scott and Fisher and one Mac and one Marantz. IMO the Fishers are the equal of any equipment made by any metric. I've been using a Fisher X1000 integrated as my main amplifier for decades (I have two of them actually), even when they were sniffed at by "audiophiles". I just love the combination of power and finesse of the 1000.

For a time, vintage Fisher tube equipment was pretty reasonably priced and undervalued (in context). My *opinion* on this is that Fisher was not only a beautifully designed and built product, but Avery Fisher was a good businessman as well. Fisher built a *lot* of stuff at reasonable prices (think Henry Ford meets Augie and Fred Duesenberg)

Since a lot of "value" is based on rarity, it's my opinion that Fishers were cheaper years ago then the average Marantz or McIntosh simply because there are so many more of them, but it seems collectors finally caught on to Fisher judging by what they're selling for nowadays.

[Trevor Wilson]

**Oh yes they are. Absolute crap. Rip one apart and you'll wonder that
they even work at all.

far from it. But they're not
> top of the tree either. If you're not spending lots of $ then piezos
> can deliver quite good performance at relatively low price. Their
> shortcoming is the frequency response is a bit uneven at the top end,
> but domes, cones etc aren't flat either.

**They have a number of serious problems that rule them out of any high
quality audio application. Sound reinforcement is probably OK, because
the listeners don't give a shit.

>
> They can be connected where your old tweeters were if you add an 8R
> resistor - piezos are high impedance devices, at least in their
> operating range. Always put a series resistor on piezos, 10R is ok.
> Otherwise the amp sees a capacitive load, and some are not ok with
> that.

**The resistor MUST be in parallel (when used with a crossover). The
capacitance exhibited by a typical piezo driver is almost
inconsequential. Any amp that runs into trouble with such a load will
have exploded years ago.

>
> Any type of tweeter comes in good & not so good variants. If I were
> buying blind (or deaf) for average consumer kit I'd be more likely to
> get a happy result from piezos than domes.
>
> Crossover frequency is typically 1 - 4kHz. Tweeters only handle
> somewhere vaguely in the region of 20% of a speaker's input power.

**Much, MUCH less than that. However, as Phil stated, they still respond
to bass frequencies and thus benefit from a crossover.


--
Trevor Wilson
www.rageaudio.com.au

[tabb...@gmail.com]

On Friday, 5 May 2017 08:12:27 UTC+1, Trevor Wilson wrote:

> On 4/05/2017 9:58 PM, tabbypurr wrote:

> > Piezos are not the 'junk' some opine,
>
> **Oh yes they are. Absolute crap.

that's not a sensible factual claim

> Rip one apart and you'll wonder that
> they even work at all.

I already know how they work, and have constructed experimental speakers using piezo technology. I don't wonder that they work, the principles are well known, and have been for a long time.

> far from it. But they're not
> > top of the tree either. If you're not spending lots of $ then piezos
> > can deliver quite good performance at relatively low price. Their
> > shortcoming is the frequency response is a bit uneven at the top end,
> > but domes, cones etc aren't flat either.
>
> **They have a number of serious problems that rule them out of any high
> quality audio application.

'high quality' is a bit too vague there. They're good enough for the average domestic hifi.

> Sound reinforcement is probably OK, because
> the listeners don't give a shit.


> > They can be connected where your old tweeters were if you add an 8R
> > resistor - piezos are high impedance devices, at least in their
> > operating range. Always put a series resistor on piezos, 10R is ok.
> > Otherwise the amp sees a capacitive load, and some are not ok with
> > that.
>
> **The resistor MUST be in parallel (when used with a crossover).

a resistor must.

> The
> capacitance exhibited by a typical piezo driver is almost
> inconsequential. Any amp that runs into trouble with such a load will
> have exploded years ago.

Maybe you should tell that to the amp I had that couldn't drive them stably without a resistor. It's clearly not factual.

> > Any type of tweeter comes in good & not so good variants. If I were
> > buying blind (or deaf) for average consumer kit I'd be more likely to
> > get a happy result from piezos than domes.
> >
> > Crossover frequency is typically 1 - 4kHz. Tweeters only handle
> > somewhere vaguely in the region of 20% of a speaker's input power.
>
> **Much, MUCH less than that.

Percentage does vary according to the music.

> However, as Phil stated, they still respond
> to bass frequencies and thus benefit from a crossover.

NT

[Trevor Wilson]

On 6/05/2017 2:08 AM, tabb...@gmail.com wrote:
> On Friday, 5 May 2017 08:12:27 UTC+1, Trevor Wilson wrote:
>> On 4/05/2017 9:58 PM, tabbypurr wrote:
>
>>> Piezos are not the 'junk' some opine,
>>
>> **Oh yes they are. Absolute crap.
>
> that's not a sensible factual claim

**Absolutely factual. They're shit. They are down there with the worst
HF drivers available.

>
>> Rip one apart and you'll wonder that they even work at all.
>
> I already know how they work, and have constructed experimental
> speakers using piezo technology. I don't wonder that they work, the
> principles are well known, and have been for a long time.

**Indeed. However, the reality is that the performance has always failed
to live up to the hype.

>
>
>> far from it. But they're not
>>> top of the tree either. If you're not spending lots of $ then
>>> piezos can deliver quite good performance at relatively low
>>> price. Their shortcoming is the frequency response is a bit
>>> uneven at the top end, but domes, cones etc aren't flat either.
>>
>> **They have a number of serious problems that rule them out of any
>> high quality audio application.
>
> 'high quality' is a bit too vague there. They're good enough for the
> average domestic hifi.

**I guess we have different ideas on what constitutes 'average domestic
hi fi'. One local manufacturer decided that piezo tweeters were a great
idea for his speaker systems. He crossed them over correctly and used a
parallel resistor to ensure the whole thing worked correctly. I used to
replace the piezos with a nice dome tweeter (after modelling and
correcting the crossover to suit of course). The result was far more
satisfying. The speakers cost (as I recall) around AUS$1,200.00/pair.
That is what I refer to as 'average domestic hi fi'.

>
>
>> Sound reinforcement is probably OK, because the listeners don't
>> give a shit.
>
>
>>> They can be connected where your old tweeters were if you add an
>>> 8R resistor - piezos are high impedance devices, at least in
>>> their operating range. Always put a series resistor on piezos,
>>> 10R is ok. Otherwise the amp sees a capacitive load, and some are
>>> not ok with that.
>>
>> **The resistor MUST be in parallel (when used with a crossover).
>
> a resistor must.
>
>> The capacitance exhibited by a typical piezo driver is almost
>> inconsequential. Any amp that runs into trouble with such a load
>> will have exploded years ago.
>
> Maybe you should tell that to the amp I had that couldn't drive them
> stably without a resistor. It's clearly not factual.

**The average capacitance exhibited by piezo tweeters is between 100nF
and 250nF. Any amplifier incapable of dealing with those amounts of
capacitance (on the end of a speaker cable and crossover) does not
deserve to be called an audio amplifier. It is no better than a door-stop.

>
>>> Any type of tweeter comes in good & not so good variants. If I
>>> were buying blind (or deaf) for average consumer kit I'd be more
>>> likely to get a happy result from piezos than domes.
>>>
>>> Crossover frequency is typically 1 - 4kHz. Tweeters only handle
>>> somewhere vaguely in the region of 20% of a speaker's input
>>> power.
>>
>> **Much, MUCH less than that.
>
> Percentage does vary according to the music.

**Of course. It is still MUCH less than 20%. More like 5%.

>
>> However, as Phil stated, they still respond to bass frequencies and
>> thus benefit from a crossover.
>
>
> NT
>

--
Trevor Wilson
www.rageaudio.com.au

[tabb...@gmail.com]

On Saturday, 6 May 2017 01:32:21 UTC+1, Trevor Wilson wrote:

I hoped you'd come back with some facts.


NT

[Phil Allison]

Trevor Wilson wrote:

>
>
> **Absolutely factual. They're shit. They are down there with the worst
> HF drivers available.
>
>

** Even a $20 Tandy horn was/is waaay better.

> >
> > Maybe you should tell that to the amp I had that couldn't drive them
> > stably without a resistor. It's clearly not factual.
>
> **The average capacitance exhibited by piezo tweeters is between 100nF
> and 250nF. Any amplifier incapable of dealing with those amounts of
> capacitance (on the end of a speaker cable and crossover) does not
> deserve to be called an audio amplifier. It is no better than a door-stop.
>

** So that would include all the Phase Linears and of course Naims.

FYI: These amps lacked output Zobel inductors.

FYI-2: Later piezos included 33ohm series resistors or tiny lamps that helped.


BTW: I have done 4 cycle tone burst tests on various piezos and lemme tell ya the results are not pretty.



.... Phil

[jurb...@gmail.com]

>"** So that would include all the Phase Linears and of course Naims.

FYI: These amps lacked output Zobel inductors.

FYI-2: Later piezos included 33ohm series resistors or tiny lamps that helped. "

Then that would include my 400-2.

However, I found a page a while back that said that coil there is not correctly referred to as a Zobel. It's not a big deal.

Had a Sony reel to reel a long time ago, had speakers. I decided to hook it to my Peavey T-1210s. They had a bank of three peizo tweeters per, and all that thing did was hum, so of course I disconnected it. It was the bias oscillator leaking into the output.

>"BTW: I have done 4 cycle tone burst tests on various piezos and lemme tell ya the results are not pretty. "

Oh, I'll bet. The things are not known for real high fidelity, to say the least. Anything peizo is non-linear and if you need anything in audio, it is linear.

I am surprised they got ceramic phono cartridges to work so well. In fact years (decades) ago I had a situation where I had a ceraic cartridge and a magnetic input on the amp. I shunted the cartridge with a resistor, I do not remember the value. It also seemed to take off the rolloff of the cartridge which normally would make RIAA EQ unecessesary. It actually sounded good going through an RIAA EQed preamp. It was an Astatic 353D IIRC. I don't remember what kind of amp, but back then I was in the amp of the week club.

But a peizo tweeter, it almost only puts out noise. If you want to claim the response and have a hot high end, cross them over at at least 8KHz, which puts second harmonic at 16 KHz. Most people will never hear it. Use a horn for up to 8 KHz if you are looking for volume.

And I do like the 33 ohm series resistor idea.

[Phil Allison]

jurb...@gmail.com wrote:

--------------------

>
> >"** So that would include all the Phase Linears and of course Naims.
>
> FYI: These amps lacked output Zobel inductors.
>
> FYI-2: Later piezos included 33ohm series resistors or tiny lamps that helped. "
>
.
>
> Then that would include my 400-2.
>

** Eeeeeeyeppp.....

> However, I found a page a while back that said that coil there is
> not correctly referred to as a Zobel. It's not a big deal.
>

** Which I did not.

I used a longer. more specific title.

>
> >"BTW: I have done 4 cycle tone burst tests on various piezos and lemme
> tell ya the results are not pretty. "
>
>
> Oh, I'll bet. The things are not known for real high fidelity,
> to say the least. Anything peizo is non-linear and if you need
> anything in audio, it is linear.
>

** Tone bursts reveal the "timer domain" behaviour of a speaker.

Good ones radiate the exact same number of cycles they are fed.

Poor one radiate an extra cycle, or two.

I found peizos were having a drunken party....

>
> And I do like the 33 ohm series resistor idea.

** Yep - it's pure genius...




..... Phil

[jurb...@gmail.com]

>" I found peizos were having a drunken party.... "

Given their theory of operation I am surprised they can even put out a reasonable approximation of a sine wave.