Can I use Pizeo Tweeters, or????

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).

$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:

Peter Wieck Melrose Park, PA

These two statements are mutually contradictory.

With that in mind, seriously:

a) any tweeter that will fit will be remarkably better than what started th ere back in the day. b) Rebuild the crossover (if any), at least replace *all* the capacitors. U se 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).

$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:

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 re asonable frequency mix, they would be a slagged mess. At a specific frequen cy, 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 inef ficient. 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 n ot 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 longe r than 1 second, the safety circuits would kick in and shut it all down any way. 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 Fis hers? No, I would not. Into my little AR4xs? Every day.

Peter Wieck Melrose Park, PA

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

I can't count how many of those Darlington STK ICs I changed in the 80s. A s 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.

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.

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....

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.

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.

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

Piezos are not the 'junk' some opine, far from it. But they're not top of t he tree either. If you're not spending lots of $ then piezos can deliver qu ite good performance at relatively low price. Their shortcoming is the freq uency 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 resisto r - piezos are high impedance devices, at least in their operating range. A lways 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

YIKES!

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

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

a) Audio Taper Controls:

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

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

c) I do not know what you listen to, in general. Whether it is classical (a s in orchestral or 'high-brow' stuff), rock, country, Polka, or whatever. B ut, *most* music as recorded these days has a Peak-to-Average of 20dB at th e high end, to under 10dB at the low end. Very, very few recordings even ap proach 30dB. So, if you are listening to well-recorded "classical" music, y our 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 thes e go back to the days of Avery Fisher (1965 or so), you will be having surr ound-rot issues and more, which you are not reporting. So, I suspect you ha ve one of their latter-day speakers that traded on the Fisher name, but wit hout the quality.

Peter Wieck Melrose Park, PA

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 m ade by any metric. I've been using a Fisher X1000 integrated as my main am plifier for decades (I have two of them actually), even when they were snif fed 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 onl y a beautifully designed and built product, but Avery Fisher was a good bus inessman as well. Fisher built a *lot* of stuff at reasonable prices (thin k Henry Ford meets Augie and Fred Duesenberg)

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