I agree with all of the above. In fact, it can be advantageous to
have an amp that is rated higher in power than the rating on the
speakers. I've seen a 40 watt amp fry a pair of speakers rated at
100 watts each due to significant abuse of the system (they were
trying to use it in a hall much larger than they should have).

That's what you get when you assume power ratings to accurately reflect true
power handling capabilities.

I agree with all of the above. In fact, it can be advantageous to
have an amp that is rated higher in power than the rating on the
speakers. I've seen a 40 watt amp fry a pair of speakers rated at
100 watts each due to significant abuse of the system (they were
trying to use it in a hall much larger than they should have).

That's what you get when you assume power ratings to accurately reflect true
power handling capabilities.

I agree with all of the above. In fact, it can be advantageous to
have an amp that is rated higher in power than the rating on the
speakers. I've seen a 40 watt amp fry a pair of speakers rated at
100 watts each due to significant abuse of the system (they were
trying to use it in a hall much larger than they should have).

That's what you get when you assume power ratings to accurately reflect true
power handling capabilities.

"MZ" wrote in message
...
The typical scenario to destroy speaker high frequency
driver in a hifi speaker is to have too low power
amplifier and running it to severe distortion.
The disortion causes lots of high frequency components
to be generated by the distortion,

No. That's an UL.
http://www.rane.com/note128.html

That Rane note says exactly the same thing. Only they refer to the
introduction of additional high frequency components as dynamic
compression.

Not exactly, they say it's NOT due to the "introduction of additional HF
components" but due to dynamic spectral compression when driven well beyond
the point of clipping. The solution is simple, turn it down when it's
distorting. If the amplifier is small enough, and the tweeter large enough
however, then clipping will NOT blow up the tweeter. OTOH a big amp will
always require some attention to it's power output.

TonyP.

"MZ" wrote in message
...
The typical scenario to destroy speaker high frequency
driver in a hifi speaker is to have too low power
amplifier and running it to severe distortion.
The disortion causes lots of high frequency components
to be generated by the distortion,

No. That's an UL.
http://www.rane.com/note128.html

That Rane note says exactly the same thing. Only they refer to the
introduction of additional high frequency components as dynamic
compression.

Not exactly, they say it's NOT due to the "introduction of additional HF
components" but due to dynamic spectral compression when driven well beyond
the point of clipping. The solution is simple, turn it down when it's
distorting. If the amplifier is small enough, and the tweeter large enough
however, then clipping will NOT blow up the tweeter. OTOH a big amp will
always require some attention to it's power output.

TonyP.

"MZ" wrote in message
...
The typical scenario to destroy speaker high frequency
driver in a hifi speaker is to have too low power
amplifier and running it to severe distortion.
The disortion causes lots of high frequency components
to be generated by the distortion,

No. That's an UL.
http://www.rane.com/note128.html

That Rane note says exactly the same thing. Only they refer to the
introduction of additional high frequency components as dynamic
compression.

Not exactly, they say it's NOT due to the "introduction of additional HF
components" but due to dynamic spectral compression when driven well beyond
the point of clipping. The solution is simple, turn it down when it's
distorting. If the amplifier is small enough, and the tweeter large enough
however, then clipping will NOT blow up the tweeter. OTOH a big amp will
always require some attention to it's power output.

TonyP.

"Rich.Andrews" wrote in message
. 1...
"MZ" wrote in
:
Because it's important to emphasize that it's not the shape of the
waveform that's the killer, but rather the amount of power being
delivered to the driver. When you just say that square waves blow
tweeters, then this implies that this is true independent of the amount
of power being delivered. This is what feeds the myth that "distortion
blows speakers." Many people, if not most, believe in this myth - that
is, a "distorted" waveform, even when absent a sufficient amount of
power, can blow a speaker. This idea is simply untrue.


I don't recall seeing a spectrum analyzer display of a square wave on the
web so I posted one. I think the point about clipping and tweeter damage
is made quite clear if you look at the jpeg I posted to
alt.binaries.schematics.electronic. The subject is 400hz square wave.
The poor tweeter is expected to reproduce all of those frequencies all at
once with harmonics well beyond it's range. That is just one frequency. I
hate to imagine if one had many frequencies clipping.

Which is exactly the point. *ANY* speaker can accommodate a 400 Hz Square
wave, or any other arbitrary waveform, *IF* the power delivered to the
drivers is less than it is designed to handle.
For tweeters that is usually in the range of 1 watt RMS continuous, to over
50 watts in the case of some horn drivers. It's simply the fact that most
tweeters fall near the lower end of the range despite claiming "system music
power" ratings of up to 100 times more, that is the cause of tweeter
failure.

TonyP.

"Rich.Andrews" wrote in message
. 1...
"MZ" wrote in
:
Because it's important to emphasize that it's not the shape of the
waveform that's the killer, but rather the amount of power being
delivered to the driver. When you just say that square waves blow
tweeters, then this implies that this is true independent of the amount
of power being delivered. This is what feeds the myth that "distortion
blows speakers." Many people, if not most, believe in this myth - that
is, a "distorted" waveform, even when absent a sufficient amount of
power, can blow a speaker. This idea is simply untrue.


I don't recall seeing a spectrum analyzer display of a square wave on the
web so I posted one. I think the point about clipping and tweeter damage
is made quite clear if you look at the jpeg I posted to
alt.binaries.schematics.electronic. The subject is 400hz square wave.
The poor tweeter is expected to reproduce all of those frequencies all at
once with harmonics well beyond it's range. That is just one frequency. I
hate to imagine if one had many frequencies clipping.

Which is exactly the point. *ANY* speaker can accommodate a 400 Hz Square
wave, or any other arbitrary waveform, *IF* the power delivered to the
drivers is less than it is designed to handle.
For tweeters that is usually in the range of 1 watt RMS continuous, to over
50 watts in the case of some horn drivers. It's simply the fact that most
tweeters fall near the lower end of the range despite claiming "system music
power" ratings of up to 100 times more, that is the cause of tweeter
failure.

TonyP.

"Rich.Andrews" wrote in message
. 1...
"MZ" wrote in
:
Because it's important to emphasize that it's not the shape of the
waveform that's the killer, but rather the amount of power being
delivered to the driver. When you just say that square waves blow
tweeters, then this implies that this is true independent of the amount
of power being delivered. This is what feeds the myth that "distortion
blows speakers." Many people, if not most, believe in this myth - that
is, a "distorted" waveform, even when absent a sufficient amount of
power, can blow a speaker. This idea is simply untrue.


I don't recall seeing a spectrum analyzer display of a square wave on the
web so I posted one. I think the point about clipping and tweeter damage
is made quite clear if you look at the jpeg I posted to
alt.binaries.schematics.electronic. The subject is 400hz square wave.
The poor tweeter is expected to reproduce all of those frequencies all at
once with harmonics well beyond it's range. That is just one frequency. I
hate to imagine if one had many frequencies clipping.

Which is exactly the point. *ANY* speaker can accommodate a 400 Hz Square
wave, or any other arbitrary waveform, *IF* the power delivered to the
drivers is less than it is designed to handle.
For tweeters that is usually in the range of 1 watt RMS continuous, to over
50 watts in the case of some horn drivers. It's simply the fact that most
tweeters fall near the lower end of the range despite claiming "system music
power" ratings of up to 100 times more, that is the cause of tweeter
failure.

TonyP.

"Colin B." wrote in message
news:40d9bf1c_2@news....
In my
(small and hard-surfaced) living room, the loudest I can stand listening
to my stereo leads to peaks of about 2W on the VU meters--continuous is
less than 1W.

Yeah, pop music is getting pretty bad with peak to average ratio's of only 6
dB or so!
For real music you will find the peaks much higher, and the average maybe
even lower.

TonyP.

"Colin B." wrote in message
news:40d9bf1c_2@news....
In my
(small and hard-surfaced) living room, the loudest I can stand listening
to my stereo leads to peaks of about 2W on the VU meters--continuous is
less than 1W.

Yeah, pop music is getting pretty bad with peak to average ratio's of only 6
dB or so!
For real music you will find the peaks much higher, and the average maybe
even lower.

TonyP.

"Colin B." wrote in message
news:40d9bf1c_2@news....
In my
(small and hard-surfaced) living room, the loudest I can stand listening
to my stereo leads to peaks of about 2W on the VU meters--continuous is
less than 1W.

Yeah, pop music is getting pretty bad with peak to average ratio's of only 6
dB or so!
For real music you will find the peaks much higher, and the average maybe
even lower.

TonyP.

That Rane note says exactly the same thing. Only they refer to the
introduction of additional high frequency components as dynamic
compression.

Not exactly, they say it's NOT due to the "introduction of additional HF
components" but due to dynamic spectral compression when driven well
beyond
the point of clipping.

They can call it whatever they want, but it's the same exact thing! Looking
at their proposition in Fourier space is identical to the notion of a mere
increase in high frequency content.

That Rane note says exactly the same thing. Only they refer to the
introduction of additional high frequency components as dynamic
compression.

Not exactly, they say it's NOT due to the "introduction of additional HF
components" but due to dynamic spectral compression when driven well
beyond
the point of clipping.

They can call it whatever they want, but it's the same exact thing! Looking
at their proposition in Fourier space is identical to the notion of a mere
increase in high frequency content.

That Rane note says exactly the same thing. Only they refer to the
introduction of additional high frequency components as dynamic
compression.

Not exactly, they say it's NOT due to the "introduction of additional HF
components" but due to dynamic spectral compression when driven well
beyond
the point of clipping.

They can call it whatever they want, but it's the same exact thing! Looking
at their proposition in Fourier space is identical to the notion of a mere
increase in high frequency content.

"MZ" wrote
"TonyP" wrote
"MZ" wrote

That Rane note says exactly the same thing. Only they refer to
the introduction of additional high frequency components as
dynamic compression.
Not exactly, they say it's NOT due to the "introduction of
additional HF components" but due to dynamic spectral
compression when driven well beyond the point of clipping.

He's got it

They can call it whatever they want, but it's the same exact thing!

Not so.

Looking
at their proposition in Fourier space is identical to the notion of a
mere increase in high frequency content.

This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...

Rudi Fischer
--
....and may good music always be with you

"MZ" wrote
"TonyP" wrote
"MZ" wrote

That Rane note says exactly the same thing. Only they refer to
the introduction of additional high frequency components as
dynamic compression.
Not exactly, they say it's NOT due to the "introduction of
additional HF components" but due to dynamic spectral
compression when driven well beyond the point of clipping.

He's got it

They can call it whatever they want, but it's the same exact thing!

Not so.

Looking
at their proposition in Fourier space is identical to the notion of a
mere increase in high frequency content.

This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...

Rudi Fischer
--
....and may good music always be with you

"MZ" wrote
"TonyP" wrote
"MZ" wrote

That Rane note says exactly the same thing. Only they refer to
the introduction of additional high frequency components as
dynamic compression.
Not exactly, they say it's NOT due to the "introduction of
additional HF components" but due to dynamic spectral
compression when driven well beyond the point of clipping.

He's got it

They can call it whatever they want, but it's the same exact thing!

Not so.

Looking
at their proposition in Fourier space is identical to the notion of a
mere increase in high frequency content.

This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...

Rudi Fischer
--
....and may good music always be with you

They can call it whatever they want, but it's the same exact thing!

Not so.

Care to elaborate?


Looking
at their proposition in Fourier space is identical to the notion of a
mere increase in high frequency content.

This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...

What's the difference between sine waves and music (or any signal for that
matter)? Nothing! Music is, of course, composed of sine waves.

Look, they claim that tweeters blow because high frequency content
increases. That's what we've been saying all along. So how on earth are
the two notions different aside from the fact that they've tagged along a
nifty phrase for it?

They can call it whatever they want, but it's the same exact thing!

Not so.

Care to elaborate?


Looking
at their proposition in Fourier space is identical to the notion of a
mere increase in high frequency content.

This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...

What's the difference between sine waves and music (or any signal for that
matter)? Nothing! Music is, of course, composed of sine waves.

Look, they claim that tweeters blow because high frequency content
increases. That's what we've been saying all along. So how on earth are
the two notions different aside from the fact that they've tagged along a
nifty phrase for it?

They can call it whatever they want, but it's the same exact thing!

Not so.

Care to elaborate?


Looking
at their proposition in Fourier space is identical to the notion of a
mere increase in high frequency content.

This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...

What's the difference between sine waves and music (or any signal for that
matter)? Nothing! Music is, of course, composed of sine waves.

Look, they claim that tweeters blow because high frequency content
increases. That's what we've been saying all along. So how on earth are
the two notions different aside from the fact that they've tagged along a
nifty phrase for it?

"MZ" pam
wrote:



I agree with all of the above. In fact, it can be advantageous to
have an amp that is rated higher in power than the rating on the
speakers. I've seen a 40 watt amp fry a pair of speakers rated at
100 watts each due to significant abuse of the system (they were
trying to use it in a hall much larger than they should have).

That's what you get when you assume power ratings to accurately reflect true
power handling capabilities.

This is true. Tweeters generally have a modest power handling capability. But
the Urban Legend about small amplifiers being dangerous to speakers is chronic
and widespread.

A few years ago at a PSACS meeting a speaker technician from an Illinois
retailer gave a talk about speaker damage and repair. When asked if small
amplifiers were dangerous to tweeters he emphatically said "oh yes" and
produced a discolored voice coil (from a small woofer) and declared that this
damage came from using a small amplifier.

Because the coil looked like several others he had shown earlier I asked how he
knew that that had been the case. He said that he knew the owner of that
speaker and had watched him "abuse that speaker with that little amp ... for
years" completely ignoring the possibility that the guy might have blown up
that speaker in much less time with a bigger amplifier.

I'm of the thought that the urban legend of small amplifiers and tweeter damage
is simply a retail technqiue to sell amplifiers when some one brings in a
damaged speaker. Because the most likely speaker damage is a blown tweeter the
Legend gets to be used most often for that situation.

I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.

"MZ" pam
wrote:



I agree with all of the above. In fact, it can be advantageous to
have an amp that is rated higher in power than the rating on the
speakers. I've seen a 40 watt amp fry a pair of speakers rated at
100 watts each due to significant abuse of the system (they were
trying to use it in a hall much larger than they should have).

That's what you get when you assume power ratings to accurately reflect true
power handling capabilities.

This is true. Tweeters generally have a modest power handling capability. But
the Urban Legend about small amplifiers being dangerous to speakers is chronic
and widespread.

A few years ago at a PSACS meeting a speaker technician from an Illinois
retailer gave a talk about speaker damage and repair. When asked if small
amplifiers were dangerous to tweeters he emphatically said "oh yes" and
produced a discolored voice coil (from a small woofer) and declared that this
damage came from using a small amplifier.

Because the coil looked like several others he had shown earlier I asked how he
knew that that had been the case. He said that he knew the owner of that
speaker and had watched him "abuse that speaker with that little amp ... for
years" completely ignoring the possibility that the guy might have blown up
that speaker in much less time with a bigger amplifier.

I'm of the thought that the urban legend of small amplifiers and tweeter damage
is simply a retail technqiue to sell amplifiers when some one brings in a
damaged speaker. Because the most likely speaker damage is a blown tweeter the
Legend gets to be used most often for that situation.

I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.

"MZ" pam
wrote:



I agree with all of the above. In fact, it can be advantageous to
have an amp that is rated higher in power than the rating on the
speakers. I've seen a 40 watt amp fry a pair of speakers rated at
100 watts each due to significant abuse of the system (they were
trying to use it in a hall much larger than they should have).

That's what you get when you assume power ratings to accurately reflect true
power handling capabilities.

This is true. Tweeters generally have a modest power handling capability. But
the Urban Legend about small amplifiers being dangerous to speakers is chronic
and widespread.

A few years ago at a PSACS meeting a speaker technician from an Illinois
retailer gave a talk about speaker damage and repair. When asked if small
amplifiers were dangerous to tweeters he emphatically said "oh yes" and
produced a discolored voice coil (from a small woofer) and declared that this
damage came from using a small amplifier.

Because the coil looked like several others he had shown earlier I asked how he
knew that that had been the case. He said that he knew the owner of that
speaker and had watched him "abuse that speaker with that little amp ... for
years" completely ignoring the possibility that the guy might have blown up
that speaker in much less time with a bigger amplifier.

I'm of the thought that the urban legend of small amplifiers and tweeter damage
is simply a retail technqiue to sell amplifiers when some one brings in a
damaged speaker. Because the most likely speaker damage is a blown tweeter the
Legend gets to be used most often for that situation.

I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.

"MZ" wrote

They can call it whatever they want, but it's the same exact
thing!
Not so.
Care to elaborate?
Looking
at their proposition in Fourier space is identical to the notion
of a
mere increase in high frequency content.
This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...
What's the difference between sine waves and music (or any signal for
that
matter)? Nothing! Music is, of course, composed of sine waves.

Oh well...

Look, they claim that tweeters blow because high frequency content
increases.

How much does the h_f_c increase if you clip music
(say +1dB, 10W Amp) relative to the unclipped signal?
Is this relative amount enough to instantly grill a tweeter?
Not so.

BTW: About 20% of modern CDs are _very_badly_ clipped.
Does that kill more tweeters?

That's what we've been saying all along.

Seems to me it will stay that way...

So how on earth are
the two notions different aside from the fact that they've tagged
along a nifty phrase for it?

And why on earth don't you try an FFT on clipped music
relative to unclipped first and than tell us the outcome?

It's simply too much power and (thermal) compression that
kills speakers, with or without signal distortion. So *big*
amps will be doing this job way *better*.

Rudi Fischer
--
....and may good music always be with you

"MZ" wrote

They can call it whatever they want, but it's the same exact
thing!
Not so.
Care to elaborate?
Looking
at their proposition in Fourier space is identical to the notion
of a
mere increase in high frequency content.
This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...
What's the difference between sine waves and music (or any signal for
that
matter)? Nothing! Music is, of course, composed of sine waves.

Oh well...

Look, they claim that tweeters blow because high frequency content
increases.

How much does the h_f_c increase if you clip music
(say +1dB, 10W Amp) relative to the unclipped signal?
Is this relative amount enough to instantly grill a tweeter?
Not so.

BTW: About 20% of modern CDs are _very_badly_ clipped.
Does that kill more tweeters?

That's what we've been saying all along.

Seems to me it will stay that way...

So how on earth are
the two notions different aside from the fact that they've tagged
along a nifty phrase for it?

And why on earth don't you try an FFT on clipped music
relative to unclipped first and than tell us the outcome?

It's simply too much power and (thermal) compression that
kills speakers, with or without signal distortion. So *big*
amps will be doing this job way *better*.

Rudi Fischer
--
....and may good music always be with you

"MZ" wrote

They can call it whatever they want, but it's the same exact
thing!
Not so.
Care to elaborate?
Looking
at their proposition in Fourier space is identical to the notion
of a
mere increase in high frequency content.
This is (you might say trivially) correct for clipped sine-waves
but not for clipped /music/. Try it...
What's the difference between sine waves and music (or any signal for
that
matter)? Nothing! Music is, of course, composed of sine waves.

Oh well...

Look, they claim that tweeters blow because high frequency content
increases.

How much does the h_f_c increase if you clip music
(say +1dB, 10W Amp) relative to the unclipped signal?
Is this relative amount enough to instantly grill a tweeter?
Not so.

BTW: About 20% of modern CDs are _very_badly_ clipped.
Does that kill more tweeters?

That's what we've been saying all along.

Seems to me it will stay that way...

So how on earth are
the two notions different aside from the fact that they've tagged
along a nifty phrase for it?

And why on earth don't you try an FFT on clipped music
relative to unclipped first and than tell us the outcome?

It's simply too much power and (thermal) compression that
kills speakers, with or without signal distortion. So *big*
amps will be doing this job way *better*.

Rudi Fischer
--
....and may good music always be with you

Look, they claim that tweeters blow because high frequency content
increases.

How much does the h_f_c increase if you clip music
(say +1dB, 10W Amp) relative to the unclipped signal?

It depends on the frequency content of the original signal and on what you
define as "high frequency". It can, of course, be calculated when you
provide those parameters.

Is this relative amount enough to instantly grill a tweeter?
Not so.

Depends on the tweeter and the high frequency content. After all, power is
the only thing that can blow a tweeter.

Anyway, I'm not sure where you're going with this line of questioning.

BTW: About 20% of modern CDs are _very_badly_ clipped.
Does that kill more tweeters?

I think you're taking a basic concept of compression in modern day CDs and
distorting the facts. But your underlying point is not one that I disagreed
with. So how does this address whether or not the Ranenote is saying the
same as what the other poster said?


So how on earth are
the two notions different aside from the fact that they've tagged
along a nifty phrase for it?

And why on earth don't you try an FFT on clipped music
relative to unclipped first and than tell us the outcome?

I've done in many many times. What are you getting at? Yes, the high
frequency content increases! That's my entire point. And what Rane is
saying is the same thing.

It's simply too much power and (thermal) compression that
kills speakers, with or without signal distortion.

Yes, too much power will blow speakers. Who argued otherwise? Certainly
not me. I don't know what "thermal compression" is. Power compression
perhaps? That won't blow speakers. In fact, it acts in the opposite
manner.

Look, they claim that tweeters blow because high frequency content
increases.

How much does the h_f_c increase if you clip music
(say +1dB, 10W Amp) relative to the unclipped signal?

It depends on the frequency content of the original signal and on what you
define as "high frequency". It can, of course, be calculated when you
provide those parameters.

Is this relative amount enough to instantly grill a tweeter?
Not so.

Depends on the tweeter and the high frequency content. After all, power is
the only thing that can blow a tweeter.

Anyway, I'm not sure where you're going with this line of questioning.

BTW: About 20% of modern CDs are _very_badly_ clipped.
Does that kill more tweeters?

I think you're taking a basic concept of compression in modern day CDs and
distorting the facts. But your underlying point is not one that I disagreed
with. So how does this address whether or not the Ranenote is saying the
same as what the other poster said?


So how on earth are
the two notions different aside from the fact that they've tagged
along a nifty phrase for it?

And why on earth don't you try an FFT on clipped music
relative to unclipped first and than tell us the outcome?

I've done in many many times. What are you getting at? Yes, the high
frequency content increases! That's my entire point. And what Rane is
saying is the same thing.

It's simply too much power and (thermal) compression that
kills speakers, with or without signal distortion.

Yes, too much power will blow speakers. Who argued otherwise? Certainly
not me. I don't know what "thermal compression" is. Power compression
perhaps? That won't blow speakers. In fact, it acts in the opposite
manner.

Look, they claim that tweeters blow because high frequency content
increases.

How much does the h_f_c increase if you clip music
(say +1dB, 10W Amp) relative to the unclipped signal?

It depends on the frequency content of the original signal and on what you
define as "high frequency". It can, of course, be calculated when you
provide those parameters.

Is this relative amount enough to instantly grill a tweeter?
Not so.

Depends on the tweeter and the high frequency content. After all, power is
the only thing that can blow a tweeter.

Anyway, I'm not sure where you're going with this line of questioning.

BTW: About 20% of modern CDs are _very_badly_ clipped.
Does that kill more tweeters?

I think you're taking a basic concept of compression in modern day CDs and
distorting the facts. But your underlying point is not one that I disagreed
with. So how does this address whether or not the Ranenote is saying the
same as what the other poster said?


So how on earth are
the two notions different aside from the fact that they've tagged
along a nifty phrase for it?

And why on earth don't you try an FFT on clipped music
relative to unclipped first and than tell us the outcome?

I've done in many many times. What are you getting at? Yes, the high
frequency content increases! That's my entire point. And what Rane is
saying is the same thing.

It's simply too much power and (thermal) compression that
kills speakers, with or without signal distortion.

Yes, too much power will blow speakers. Who argued otherwise? Certainly
not me. I don't know what "thermal compression" is. Power compression
perhaps? That won't blow speakers. In fact, it acts in the opposite
manner.

Nousaine wrote:
stuff deleted
I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.


An interesting response but perhaps a little anticdotal. The
shortest job that I ever had was once I was hired to be a
bricklayer's helper. I was healthy, but not a really strong guy.
I was strong enough to lift buckets of morter and concrete but
after a short while I would get a little shakey. I spilled some
concrete once or twice on a wall because of my lack of strength.
If they had hired a stronger guy, it wouldn't have happened. If
they had hired a 3 year old kid, it ALSO wouldn't have happened
since the kid wouldn't have had the strength to even lift the
bucket in the first place. To say that the damage I caused was
not due to my lack of strength/control and say the proof is that
someone with even less strengh wouldn't cause any damage seems to
ignores some key elements of logic somewhere :-)

The problem is where there is enough power to get things going
but not enough to control things well. If my boss missed the
issue and somehow thought I could do twice as much work, he might
of made me carry two buckets at a time (like the other "Charles
Atlas" helper he had). Since I COULD lift two buckets, you might
say I could do it, but I suspect that there would have been twice
as much damage.

The issue with the speaker ratings is that they never tell you
how the rated power can be safely distributed across the spectrum
of the speaker or how they even arrived at the rating in the
first place. A "50 watt" speaker may only be rated for 1/4 watt
across the 5KHz to 20KHz band. As has been pointed out before, a
speaker rating is not linear across its entire bandwidth.

There may be some standards for speaker power rating but I don't
think that I've ever come across one.

- Jeff

Nousaine wrote:
stuff deleted
I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.


An interesting response but perhaps a little anticdotal. The
shortest job that I ever had was once I was hired to be a
bricklayer's helper. I was healthy, but not a really strong guy.
I was strong enough to lift buckets of morter and concrete but
after a short while I would get a little shakey. I spilled some
concrete once or twice on a wall because of my lack of strength.
If they had hired a stronger guy, it wouldn't have happened. If
they had hired a 3 year old kid, it ALSO wouldn't have happened
since the kid wouldn't have had the strength to even lift the
bucket in the first place. To say that the damage I caused was
not due to my lack of strength/control and say the proof is that
someone with even less strengh wouldn't cause any damage seems to
ignores some key elements of logic somewhere :-)

The problem is where there is enough power to get things going
but not enough to control things well. If my boss missed the
issue and somehow thought I could do twice as much work, he might
of made me carry two buckets at a time (like the other "Charles
Atlas" helper he had). Since I COULD lift two buckets, you might
say I could do it, but I suspect that there would have been twice
as much damage.

The issue with the speaker ratings is that they never tell you
how the rated power can be safely distributed across the spectrum
of the speaker or how they even arrived at the rating in the
first place. A "50 watt" speaker may only be rated for 1/4 watt
across the 5KHz to 20KHz band. As has been pointed out before, a
speaker rating is not linear across its entire bandwidth.

There may be some standards for speaker power rating but I don't
think that I've ever come across one.

- Jeff

Nousaine wrote:
stuff deleted
I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.


An interesting response but perhaps a little anticdotal. The
shortest job that I ever had was once I was hired to be a
bricklayer's helper. I was healthy, but not a really strong guy.
I was strong enough to lift buckets of morter and concrete but
after a short while I would get a little shakey. I spilled some
concrete once or twice on a wall because of my lack of strength.
If they had hired a stronger guy, it wouldn't have happened. If
they had hired a 3 year old kid, it ALSO wouldn't have happened
since the kid wouldn't have had the strength to even lift the
bucket in the first place. To say that the damage I caused was
not due to my lack of strength/control and say the proof is that
someone with even less strengh wouldn't cause any damage seems to
ignores some key elements of logic somewhere :-)

The problem is where there is enough power to get things going
but not enough to control things well. If my boss missed the
issue and somehow thought I could do twice as much work, he might
of made me carry two buckets at a time (like the other "Charles
Atlas" helper he had). Since I COULD lift two buckets, you might
say I could do it, but I suspect that there would have been twice
as much damage.

The issue with the speaker ratings is that they never tell you
how the rated power can be safely distributed across the spectrum
of the speaker or how they even arrived at the rating in the
first place. A "50 watt" speaker may only be rated for 1/4 watt
across the 5KHz to 20KHz band. As has been pointed out before, a
speaker rating is not linear across its entire bandwidth.

There may be some standards for speaker power rating but I don't
think that I've ever come across one.

- Jeff

Nousaine wrote:
stuff deleted
I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.

Okay, let's look at this problem slightly differently and see if it makes more
sense.

When a small amp goes into heavy clipping it produces a signal that looks pretty
much like a square wave. Forget about the harmonic train for a moment and just
look at (or consider) the shape of the signal: a sudden rise to the top, it
stays there for a while, then a sudden drop to the bottom, where it stays for a
while, and then it repeats all over again.

There's another way to describe that kind of signal: pulsating DC. For a
speaker, it's a hard signal to handle. The speaker moves out and simply sits
there, then it moves in, and sits there. While it's just sitting there, being
held out (or in) by the voltage, the temperature in the voice coil is rising,
since there's no way to dissipate the heat from the "DC" that's holding the
speaker still. Do that long enough (even at lower than maximum speaker ratings)
and the coil will eventually burn up.

Is that easier to grasp?
Harvey Gerst
Indian Trail Recording Studio
http://www.ITRstudio.com/

Nousaine wrote:
stuff deleted
I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.

Okay, let's look at this problem slightly differently and see if it makes more
sense.

When a small amp goes into heavy clipping it produces a signal that looks pretty
much like a square wave. Forget about the harmonic train for a moment and just
look at (or consider) the shape of the signal: a sudden rise to the top, it
stays there for a while, then a sudden drop to the bottom, where it stays for a
while, and then it repeats all over again.

There's another way to describe that kind of signal: pulsating DC. For a
speaker, it's a hard signal to handle. The speaker moves out and simply sits
there, then it moves in, and sits there. While it's just sitting there, being
held out (or in) by the voltage, the temperature in the voice coil is rising,
since there's no way to dissipate the heat from the "DC" that's holding the
speaker still. Do that long enough (even at lower than maximum speaker ratings)
and the coil will eventually burn up.

Is that easier to grasp?
Harvey Gerst
Indian Trail Recording Studio
http://www.ITRstudio.com/

Nousaine wrote:
stuff deleted
I sometimes challange the Legend with what I call the "Underpowering Contra
Argument". If "underpowering" with a small amplifier were the true cause of
speaker damage then driving one with the output from your preamplifier or from
the headphone jack on a walkman should be avoided at all cost.

Okay, let's look at this problem slightly differently and see if it makes more
sense.

When a small amp goes into heavy clipping it produces a signal that looks pretty
much like a square wave. Forget about the harmonic train for a moment and just
look at (or consider) the shape of the signal: a sudden rise to the top, it
stays there for a while, then a sudden drop to the bottom, where it stays for a
while, and then it repeats all over again.

There's another way to describe that kind of signal: pulsating DC. For a
speaker, it's a hard signal to handle. The speaker moves out and simply sits
there, then it moves in, and sits there. While it's just sitting there, being
held out (or in) by the voltage, the temperature in the voice coil is rising,
since there's no way to dissipate the heat from the "DC" that's holding the
speaker still. Do that long enough (even at lower than maximum speaker ratings)
and the coil will eventually burn up.

Is that easier to grasp?
Harvey Gerst
Indian Trail Recording Studio
http://www.ITRstudio.com/

Okay, let's look at this problem slightly differently and see if it makes
more
sense.

When a small amp goes into heavy clipping it produces a signal that looks
pretty
much like a square wave. Forget about the harmonic train for a moment and
just
look at (or consider) the shape of the signal: a sudden rise to the top,
it
stays there for a while, then a sudden drop to the bottom, where it stays
for a
while, and then it repeats all over again.

There's another way to describe that kind of signal: pulsating DC. For a
speaker, it's a hard signal to handle. The speaker moves out and simply
sits
there, then it moves in, and sits there. While it's just sitting there,
being
held out (or in) by the voltage, the temperature in the voice coil is
rising,
since there's no way to dissipate the heat from the "DC" that's holding
the
speaker still. Do that long enough (even at lower than maximum speaker
ratings)
and the coil will eventually burn up.

Is that easier to grasp?

Unfortunately, it doesn't really clarify anything. In fact, it muddies
things up even more. First of all, there's not really such a thing as
"pulsating DC". That's an oxymoron. If it's "pulsating", it's by
definition an AC signal.

The rest of what you say would be true only if the fundamental was on the
order of fractions of a Hz. It's a nice idea, but it's simply not the way
it works. The voice coil doesn't care a whole lot about the motion
waveform - it just cares that motion is occurring. Whether it's a square
wave or a sine wave, it makes no difference. Also, due to the inductance of
the voice coil and the limitations of the amplifier, most speakers will
generally not move in a square wave fashion anyway, even when the amplifier
is severely clipped.

Okay, let's look at this problem slightly differently and see if it makes
more
sense.

When a small amp goes into heavy clipping it produces a signal that looks
pretty
much like a square wave. Forget about the harmonic train for a moment and
just
look at (or consider) the shape of the signal: a sudden rise to the top,
it
stays there for a while, then a sudden drop to the bottom, where it stays
for a
while, and then it repeats all over again.

There's another way to describe that kind of signal: pulsating DC. For a
speaker, it's a hard signal to handle. The speaker moves out and simply
sits
there, then it moves in, and sits there. While it's just sitting there,
being
held out (or in) by the voltage, the temperature in the voice coil is
rising,
since there's no way to dissipate the heat from the "DC" that's holding
the
speaker still. Do that long enough (even at lower than maximum speaker
ratings)
and the coil will eventually burn up.

Is that easier to grasp?

Unfortunately, it doesn't really clarify anything. In fact, it muddies
things up even more. First of all, there's not really such a thing as
"pulsating DC". That's an oxymoron. If it's "pulsating", it's by
definition an AC signal.

The rest of what you say would be true only if the fundamental was on the
order of fractions of a Hz. It's a nice idea, but it's simply not the way
it works. The voice coil doesn't care a whole lot about the motion
waveform - it just cares that motion is occurring. Whether it's a square
wave or a sine wave, it makes no difference. Also, due to the inductance of
the voice coil and the limitations of the amplifier, most speakers will
generally not move in a square wave fashion anyway, even when the amplifier
is severely clipped.

Okay, let's look at this problem slightly differently and see if it makes
more
sense.

When a small amp goes into heavy clipping it produces a signal that looks
pretty
much like a square wave. Forget about the harmonic train for a moment and
just
look at (or consider) the shape of the signal: a sudden rise to the top,
it
stays there for a while, then a sudden drop to the bottom, where it stays
for a
while, and then it repeats all over again.

There's another way to describe that kind of signal: pulsating DC. For a
speaker, it's a hard signal to handle. The speaker moves out and simply
sits
there, then it moves in, and sits there. While it's just sitting there,
being
held out (or in) by the voltage, the temperature in the voice coil is
rising,
since there's no way to dissipate the heat from the "DC" that's holding
the
speaker still. Do that long enough (even at lower than maximum speaker
ratings)
and the coil will eventually burn up.

Is that easier to grasp?

Unfortunately, it doesn't really clarify anything. In fact, it muddies
things up even more. First of all, there's not really such a thing as
"pulsating DC". That's an oxymoron. If it's "pulsating", it's by
definition an AC signal.

The rest of what you say would be true only if the fundamental was on the
order of fractions of a Hz. It's a nice idea, but it's simply not the way
it works. The voice coil doesn't care a whole lot about the motion
waveform - it just cares that motion is occurring. Whether it's a square
wave or a sine wave, it makes no difference. Also, due to the inductance of
the voice coil and the limitations of the amplifier, most speakers will
generally not move in a square wave fashion anyway, even when the amplifier
is severely clipped.

"MZ" wrote in message

Okay, let's look at this problem slightly differently and see if it
makes more sense.

When a small amp goes into heavy clipping it produces a signal that
looks pretty much like a square wave. Forget about the harmonic
train for a moment and just look at (or consider) the shape of the
signal: a sudden rise to the top, it
stays there for a while, then a sudden drop to the bottom, where it
stays for a while, and then it repeats all over again.

There's another way to describe that kind of signal: pulsating DC.
For a speaker, it's a hard signal to handle. The speaker moves out
and simply sits there, then it moves in, and sits there. While it's
just sitting there, being held out (or in) by the voltage, the
temperature in the voice coil is rising, since there's no way to
dissipate the heat from the "DC" that's holding the
speaker still. Do that long enough (even at lower than maximum
speaker ratings) and the coil will eventually burn up.

Is that easier to grasp?

Unfortunately, it doesn't really clarify anything. In fact, it
muddies things up even more. First of all, there's not really such a
thing as "pulsating DC". That's an oxymoron. If it's "pulsating",
it's by definition an AC signal.

Your skepticism is IMO well-founded.

When you cleanly clip a music waveform, it doesn't just look like a square
wave, it is a variable-frequency square wave. However, there's no guarantee
that a true POS power amp will clip cleanly. What this comes down to is that
a POS is a POS, and using a POS power amp can be dangerous to your system,
no matter what its power rating is.

If we drop the POS power amps from the discussion, we're left with what
happens with a competent low power amp as opposed to what happens to a
competent high powered amp.

To understand this better, you have to consider how speakers fail. IME the
most common form of driver failure is caused by overheating of the voice
coil. Second is fracturing of the voice coil wiring due to excess flexing. A
third failure mode relates to over-travel of the cone. These three most
common loudspeaker driver failure modes have a common cause - too much
power.

Much has been written about spectral shifting due to clipping, and this can
clearly stimulate the first and second modes of failure by causing more
power to be routed to high frequency drivers.

However, there's a lot of music around whose high frequency spectral
content actually decreases when it is cleanly clipped, and even more where
there are no appreciable changes.

Classical music is one genre where upward spectral shifting can still be
dominant, but even there it's not a sure thing. During crescendos crashing
cymbals and blaring horns can build up a lot of power at high frequencies.

The bottom line is that most of the failure modes of drivers come from the
driver receiving too much power, too long. The easiest way to get more power
to a speaker is to have a more powerful amplifier. These days, 100 wpc power
amps are unbelievably inexpensive. 100 wpc is a lot of power for most
consumer speakers to handle, long term.

Intensely powerful *accidents* are more likely with more powerful
amplifiers.

More powerful amplifiers also provide a psychoacoustic cause for speaker
damage. Undistorted music often sounds less loud than distorted music with
equal power. Therefore, a listener is more likely to apply more power to his
speakers with a more powerful amplifier. In the absence of clipping, the
music will not sound as loud as it will if it is clipped.

That all said, I have just a few kilowatts of power amps around the house,
and most of them are hooked to speakers. The good news for my speakers is
that I have a lot of fairly robust speakers, and I try to be careful.

I don't think there is any doubt that over the past 30 years loudspeakers
have become as a rule, more robust.