hello,

Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?

wrote in message
hello,

Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?



** Quote the post - TROLL.



.......... Phil

wrote:
Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?

I think he indicated that _clipping_ was really bad for speakers since
it could cause them to overheat. Other forms of distortion, probably
not, unless you're applying a strong DC component to the signal...

See the other posts in that thread for much flamage on the topic.

On Thu, 1 Dec 2005 14:51:20 +1100, "Phil Allison"
wrote:


wrote in message
hello,

Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?



** Quote the post - TROLL.



......... Phil


Damn . . .

I thought my killfilter was working. Suddenly Miss Manners pops up
again with polite and handy usenet etiquette tips.

It's like whack-a-mole with a human witchetty grub.







Kurt Riemann

Kurt Riemann
"Phil Allison"


Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?


** Quote the post - TROLL.



Damn . . .

I thought my killfilter was working. Suddenly Miss Manners pops up
again with polite and handy usenet etiquette tips.


** Gawd - the anencephalic Moose ****er is back.

Hide your pet sheep - he thinks they are blonde moose babes.




........... Phil

wrote:

hello,

Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?

'Distortion' per se is mainly irrelevant.

Very large distortion - e.g. severe clipping - may present a problem since
it will be full of harmonics whose energy may well be in the tweeter band
and this may 'overload' the tweeter e.g. burn it out.

In such circumstances an unclipped signal from a 'bigger' amplifier may
actually be kinder on the speaker despite the apparently larger power.

In any case you should be able to hear clipping and turn it down.

Graham

wrote in message
oups.com
hello,

Mr. Dorsey indicated in a recent post that distortion is
really bad for speakers. Why is that?

Close to my heart right now because I found a dead stage
monitor last night, no doubt due to an overdrive accident
that happened since last Sunday. I'm not sure what happened,
but the woofer was toast.

In estimated order of importance:

(1) When you clip things, its usually because you're running
an excessively large signal. Excessively large signals are
really bad for speakers. Amps clip and play another day, but
speakers burn out and then you must repair or replace or do
without.

(2) Clipping compresses the dynamics of the signal. A
compressed signal generally contains higher average power
than an uncompressed signal.

(3) Clipping may or may not change the spectral energy
distribution in a signal. Clipping makes really bright
sounds seem duller, which means that high frequency energy
is reduced. Clipping has less impact on less-bright sounds,
and may not change their energy distribution that much.
Clipping can make darker sounds seem brighter, which means
that energy is being redirected to the higher frequency
ranges.

If you change the spectral energy distribution of a signal
it may stress different parts of a speaker, particularly the
mids and tweeters.

(4) Some equipment does not clip cleanly, and may even
misbehave quite a bit when clipped. It may send out subsonic
pulses and other nasties that are not strictly related to
the music, which is different from the usual harmonics
generation.

Arny Krueger wrote:
Close to my heart right now because I found a dead stage
monitor last night, no doubt due to an overdrive accident
that happened since last Sunday. I'm not sure what happened,
but the woofer was toast.

So much for all these theories about clipping producing harmonics which
burn out the tweeter. I've never really bought that as an explanation:
to do that the clipping would have to besevere enough to trash the sound.

Thanks for a set of much more plausible explanations, especially the
point about clipping causing compression. It's the thermal effect of
those average levels that's doing much of the damage.

I'd guess that a heavily compressed sound with low peak-average ratio
could also be a hazard for speakers, even if the peaks never clipped the
amp.

Anahata

For what I know clipping an amplifier makes the amp output AC..... THAT is
very bad for speakers....
F.

"Federico"

For what I know clipping an amplifier makes the amp output AC..... THAT is
very bad for speakers....


** Abso****ingbloominglootley !!!!

AC is just terrible for loudspeakers !!!

If a loudspeaker was never fed any AC or DC it would NEVER fail !!!

The simplest and most blindingly obvious fact about loudspeakers that
EVERYONE has missed is:


** Leave it in the packing carton = NO FAILURES **





........ Phil

On Thu, 1 Dec 2005 14:24:00 +0100, "Federico"
wrote:

For what I know clipping an amplifier makes the amp output AC..... THAT is
very bad for speakers....
F.

Not half as bad as DC. AC is what speakers are designed to work with.

d

Pearce Consulting
http://www.pearce.uk.com

wrote:

Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?

No, I said _clipping_ is really bad for speakers. Clipping is only ONE
of many kinds of distortion.

And the reason is because it contains a lot of high frequency trash, some
of which is ultrasonic. The tweeters try very hard to reproduce it, but
they can't move quickly enough, and the residual energy becomes heat.
Most speakers are very displeased about dealing with ultrasonics, and
many are displeased at dealing with high levels of audible high frequencies.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Anahata wrote:
Arny Krueger wrote:
Close to my heart right now because I found a dead stage
monitor last night, no doubt due to an overdrive accident
that happened since last Sunday. I'm not sure what happened,
but the woofer was toast.

So much for all these theories about clipping producing harmonics which
burn out the tweeter. I've never really bought that as an explanation:
to do that the clipping would have to besevere enough to trash the sound.

Yes, it does have to be severe enough to trash the sound. I go to
concerts _all the time_ where the sound has been trashed.

I have worked with PA guys who turn the sound up until they can hear
the system clipping. That's how they know it's loud enough. They
judge the operating level by the amount of clipping. Give them a
system with a lot of headroom and they just keep turning it up and
complaining it doesn't sound loud to them.

Thanks for a set of much more plausible explanations, especially the
point about clipping causing compression. It's the thermal effect of
those average levels that's doing much of the damage.

That's right. Speakers blow for two reasons: thermal effects from
lots of signal that can't be reproduced, and mechanical damage from
exceeding excursion limits. One is a slow effect, the other is a
fast effect, and because of this there are two protection mechanisms
required on speaker cabinets.

I'd guess that a heavily compressed sound with low peak-average ratio
could also be a hazard for speakers, even if the peaks never clipped the
amp.

This can be true, but in this case you have the speaker ratings to tell
you how much power you can safely put into the cabinet. The problems
start when you start putting stuff into the cabinet that is either too
high or too low for the drivers to reproduce. Poor crossover design
can also be an issue here in that it can allow drivers to see signal
that is too high or too low for them to handle at a given power level.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Of course I meant DC, not AC... sorry....
F.

In Italian we call it with other names (CC and CA).... I'm not used to AC
and DC......

Scott Dorsey wrote:
wrote:
Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?

No, I said _clipping_ is really bad for speakers.

As someone else asked in the other thread, why, then, is the kind of
clipping that is built into nearly all modern CD's, many with some
severity, not damaging to speakers?

It's not clipping, it's excess power. Clipped material, whether from
the amp, or from the source, or wherever has relatively more HF energy
than that which is not clipped which can expose the HF drivers sooner
than non-clipped material. There is no fast rule that clipping will
damage a speaker. It will do so if and only if the amp is delivering
more power than a driver can handle.


Bob
--

"Things should be described as simply as possible, but no simpler."

A. Einstein

You all probably have more knowledge and experience than I so take my
post with a grain of salt.

I agree with a number of things people have posted, but maybe a
different approach might help people who think more like I do.

Clipping, by its very nature creates waveforms that approach square
waves: __|''''''''|__|''''''''|__ etc. Of course it wouldn't be able to
reach that totally, but for our purposes let's say it does. So, with a
severly clipped signal you are basically sending a square wave to the
speaker. Speakers are designed to convert the foward and backward flow
of the current presented to it (AC) into the foward and backward motion
of the speaker cone, horn diaphragm, etc. In a square wave, the
current is essentially instantly foward, holds there for a very small
period of time, then instantly backward, then holds, then is repeated.
Sure, this may work electrically, but mechanically it can't. The
speaker cone can't be in the "foward" position, then instantly in the
"back" position. Even if you do this with, say, your hand you feel the
strain. Put your hand in one spot, then IMMEDIATELY move it no a new
spot and go back and forth. Your arm should get tired and rightly so.

I don't know what specific effect this causes to make the speaker die,
but I'm guessing it's the thermal issues other posters have spoken of.

I hope this helps somebody, and if this is all wrong, please let me
know so I don't put my faith in something incorrect.

-steve

"elecbanana"

I hope this helps somebody, and if this is all wrong, please let me
know so I don't put my faith in something incorrect.


** It is UTTERLY and COMPLETELY W R O N G !!!!!!!!!!!!!!


The simple fact is that woofer cone motion does NOT follow the input voltage
waveform.

It follows the second integral of that waveform ( in the passband).

Eg.

A woofer fed with a 100 Hz square wave moves pretty much in a SINE WAVE
motion to reproduce the square wave in the air.

A woofer fed with a 1000 Hz square wave HARDLY MOVES AT ALL !!

Amazing - eh ??




......... Phil

It's not clipping, it's excess power. Clipped material, whether from
the amp, or from the source, or wherever has relatively more HF energy
than that which is not clipped which can expose the HF drivers sooner
than non-clipped material. There is no fast rule that clipping will
damage a speaker. It will do so if and only if the amp is delivering
more power than a driver can handle.

Finally. A sane comment on the subject.

"William Sommer****wit"

It's not clipping, it's excess power. Clipped material, whether from
the amp, or from the source, or wherever has relatively more HF energy
than that which is not clipped which can expose the HF drivers sooner
than non-clipped material. There is no fast rule that clipping will
damage a speaker. It will do so if and only if the amp is delivering
more power than a driver can handle.

Finally. A sane comment on the subject.




** As if.

The simple fact is that 90% of speakers spend their lives connected to
amplifiers the can easily destroy them.

But like wives and their husbands.




............ Phil

The simple fact is that 90% of speakers spend their lives
connected to amplifiers the can easily destroy them.

This is true, but the destruction is almost always caused by listener
abuse -- turning up the volume well past the point of audible distortion.

"William Sommer******"

The simple fact is that 90% of speakers spend their lives
connected to amplifiers the can easily destroy them.

This is true, but the destruction is almost always caused by listener
abuse -- turning up the volume well past the point of audible distortion.



** Sigh - what an annoying autistic ****wit.



........ Phil

Bob Cain wrote:
Scott Dorsey wrote:
wrote:
Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?

No, I said _clipping_ is really bad for speakers.

As someone else asked in the other thread, why, then, is the kind of
clipping that is built into nearly all modern CD's, many with some
severity, not damaging to speakers?

It's not as bad as it _could_ be, because the reconstruction filter in
the CD player is going to remove all the ultrasonic trash. So what is
getting to the speakers doesn't include a lot of trash that the tweeters
are unable to reproduce, like happens when an amplifier clips.

It's not clipping, it's excess power. Clipped material, whether from
the amp, or from the source, or wherever has relatively more HF energy
than that which is not clipped which can expose the HF drivers sooner
than non-clipped material.

Right, and the increase in high frequency content from clipping in
mastering IS bad for speakers for just that reason... there is now
more HF content and more HF power at a given overall level. But it
is not as catastrophically bad as clipping the amps.

There is no fast rule that clipping will
damage a speaker. It will do so if and only if the amp is delivering
more power than a driver can handle.

Right. The problem is that a typical tweeter can't handle much power
at all at 30 KHz. It can't move that fast, and so it all turns to heat.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey"

Right. The problem is that a typical tweeter can't handle much power
at all at 30 KHz. It can't move that fast, and so it all turns to heat.




** Oh my god !!!!!!!!!!!

Is there no end to the *diabolical crapology* this Dorsey IDIOT can post.

He must be in line for a Oscar in Bull**** Artistry !!!




"C'est un Nagra. C'est suisse, et tres, tres precis."


** C'est un Dorsey. C'est a poostering ferkwitt.




........... Phil

Bob Cain wrote:

No, I said _clipping_ is really bad for speakers.

As someone else asked in the other thread, why, then, is the kind of
clipping that is built into nearly all modern CD's, many with some
severity, not damaging to speakers?

It's not clipping, it's excess power. Clipped material, whether from
the amp, or from the source, or wherever has relatively more HF energy
than that which is not clipped which can expose the HF drivers sooner
than non-clipped material. There is no fast rule that clipping will
damage a speaker. It will do so if and only if the amp is delivering
more power than a driver can handle.

Yes, that's certainly true. But here's the issue: Since most music has
much of its power represented in the lower frequencies, most speaker
systems are designed to handle much more power at lower frequencies than
at higher frequencies. When an amplifier is pushed to clipping, two
things occur that skew this balance.

1) The clipped low frequencies take on the characteristics of square
waves. Square waves are mathematically made up of harmonics of the
original frequency, the result is an unnaturally high amount of power
being routed by the crossover to the tweeter. However, mathematical
analysis suggests that the amount of power involved in this phenomenon
alone is not enough to damage most tweeters.

2) As the overall signal is increased in level, the low frequencies
(which are at the highest amplitudes) get clipped. They can't cause the
amp to produce more power than it is capable of delivering, so they "max
out" at the power ceiling for the amp. However, the high frequency
component of the music just keeps getting louder - it started out at a
much lower level, so there is still room for it to increase in loudness.
As a result, the signal going to the speaker now contains a much higher
proportion of high frequencies than it did before amplification.

So the final signal has more highs - a lot more - both because of the
low frequency clipping and because of the high amplification of the
original high frequency content. The result, eventually, is a blown
tweeter.

As you observe, the problem isn't clipping per se, it is excessive
amplification. But it is still an underpowered amplifier driven to
clipping that represents the problem.

For a better explanation than I could ever write, see:

http://www.rane.com/note128.html

** I am UTTERLY and COMPLETELY S O R R Y !!!!!!!!!!!!!!
for being such a moron.

"Phil Allison" wrote in
:

"William Sommer******"

The simple fact is that 90% of speakers spend their lives
connected to amplifiers the can easily destroy them.

This is true, but the destruction is almost always caused by listener
abuse -- turning up the volume well past the point of audible
distortion.

** Sigh - what an annoying autistic ****wit.

Phil, please justify your statement. I have been following this thread
trying to stay up on the math and the physics. Lord knows I've blown
enough speakers in my time and would like to stop.

How can you destroy a speaker that isn't being driven into distortion?
Granted the amp might not be overdriving, but the speaker must, mustn't it?

Jim,
Thanks for the link to Rane's explanation. That was very helpful
and makes a lot of sense. What I was explaining in my first post in
this thread is the concept of introduced high frequencies due to
clipping into square waves. I totally believe the Rane article and you
Jim, but I am not cinvinced yet that the square wave-high frequency
thing couldn't also be a possible culprit in the right situation. What
if you fed a low frequency sine wave into an amp, clipped it like mad,
then sent it to a speaker? In this situation, could this blow the
tweeter? In the Rane article it puts the blame on the original high
frequency content getting amplified past the handling of the tweeter,
but what if there is no high frequency content? I know this isn't a
situation that would happen very much in real life, but I like to
understand every aspect of something if I can. The only example I can
think of at the moment is using an external crossover, then sending the
low end to an amp, clipping it, and sending the output to a 2-way
speaker (because that's all you can find or something). Say, in the
case of some terribly rigged up bass amp cranked up toward the end of
the gig. Could this blow the tweeter in the 2-way speaker?

Again, I am not arguing, just wanting to know more.

-steve

Carey Carlan wrote:

How can you destroy a speaker that isn't being driven into distortion?

Call the Teamsters.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Phil Allison" wrote in
:


"Scott Dorsey"

Right. The problem is that a typical tweeter can't handle much power
at all at 30 KHz. It can't move that fast, and so it all turns to
heat.




** Oh my god !!!!!!!!!!!

Is there no end to the *diabolical crapology* this Dorsey IDIOT can
post.

He must be in line for a Oscar in Bull**** Artistry !!!




"C'est un Nagra. C'est suisse, et tres, tres precis."


** C'est un Dorsey. C'est a poostering ferkwitt.




.......... Phil




Phil, I love you man.
You are the one saving grace to this newsgroup.

Hey there electricalbanana, I see you have thrown yourself to the
wolves here and they have attacked, but truth is you were homing in on
the real answer in your first post.

If one considers two situations the problem starts to become obvious.
Take an amplifier and a speaker. The amplifier, if solid state, will
ususally have a maximum voltage limit. When you feed in a sinewave at a
given frequency so that the peaks of the sinewave are at the voltage
limit of the amp, that is usually the rms power rating of the
amplifier. If you hook that amp to a speaker also rated at that rms
power, everything is hunky dory.

BUT if as you note you take that sinewave input and really crank it up
so the amp clips (voltage limit, remember?) the output soon closely
approximates a square wave. So now take that sinewave with a peak
voltage of V giving a certain power P, and then caclulate the power in
a square wave of the same peak voltage V. Whoa! You discover that the
power in that waveform is 2P! (The reason being that the sinewave
spends considerable time below max voltage.)

OK. So now you see that if you have a 100 watt amp and speaker, hard
clipping will tend to pump 200 watts into the speaker. Since the
speaker is only rated at 100 watts rms continuous, doubling the input
power over the rating has a tendency to turn it into toast.
=========

Now the case with tweeters is similar but sligtly different. First off
tweeters tend to have power ratings well below the rms rating of the
associated woofer. The reason is that it doesn't take a lot of power to
make high freqencies loud and furthermore the high frequency power in
music is usually well below the average power. So people can easily get
away with under-rating tweeters. But that is only if things are going
right. So you get away with a 20 watt tweeter in a 100 watt speaker
system.

But what if there is a mic feedback? Now you've got full amplifier
power at a single frequency into the tweeter! Toast. What if there is
no feedback but you are cranking the amp till it clips like mad. Two
things: First you've got your amp putting out twice rated power, and
furthermore the clipped waveforms are filled with high frequency
harmopnics. So you've shifted the music power balance so that there is
MUCH more energy in the tweeter range. So you've created a situation
where you've now got 200 watts of potential amplifier power into your
"compromise" 20 watt tweeter. Needless to say this will not long stay a
happy situation.

In answer to your question about blowing a tweeter in a two-way bass
rig, no, generally basses as a source do not have enough sustained
high frequency content to blow a tweeter even when clipped. Slapping
can create lots of highs but it's usually quite transient so the
average power is lower. But bass players can and often DO blow bass
speakers from clipping. If you feed those sustained bass notes into a
given amp and then crank it so it clips, chances are you'll be putting
twice the rated power into the speaker and kiss it goodbye. As someone
here noted bass players typically tend to try to use larger amps with
lower rated speakers which sounds as if it's a mistake, but it's not.
This is because the larger amp won't clip and it lets you hear when the
speaker itself is starting to strain. You can still blow a speaker, of
course, but you'll have much more control over doing it. :-)

Benj

"Carey Carlan"
"Phil Allison"
"William Sommer******"

The simple fact is that 90% of speakers spend their lives
connected to amplifiers the can easily destroy them.

This is true, but the destruction is almost always caused by listener
abuse -- turning up the volume well past the point of audible
distortion.

** Sigh - what an annoying autistic ****wit.

Phil, please justify your statement.


** That Sommer****** is an autistic ****wit ?



How can you destroy a speaker that isn't being driven into distortion?



** Huh - where is that idea anything that I posted about ?



......... Phil

On Fri, 02 Dec 2005 09:45:52 -0500, Jim Gilliland
wrote:

As you observe, the problem isn't clipping per se, it is excessive
amplification. But it is still an underpowered amplifier driven to
clipping that represents the problem.

Speaker driver abuse failures come from exceeding either
excursion or thermal limits.

Your point that the culprit is the hand on the fader
pretty much covers it completely.

Chris Hornbeck

sorry- clipping. didn't mean to mis-quote you.

that's interesting about ultrasonics and the tweeters "trying hard". i
thought if it was out of the effective band of the driver, the driver
would simply ignore the signal more and more because it can't "see" the
sound at that frequency range. but if i understand you correctly, a
driver might be trying to produce that sound.

i learn something new each week here. thank you.

that's interesting information on subsonics and brightness effects of
harmonics.

that's interesting about ultrasonics and the tweeters "trying hard". i
thought if it was out of the effective band of the driver, the driver
would simply ignore the signal more and more because it can't "see" the
sound at that frequency range. but if i understand you correctly, a
driver might be trying to produce that sound.

It doesn't matter whether the driver "tries" to reproduce the sound, or not.
The voice coil still has to dissipate the power.

If you put 50 watts at 1MHz into a tweeter that can only handle 5 watts, you
_will_ burn it out.

Bob Cain wrote:

Scott Dorsey wrote:
wrote:
Mr. Dorsey indicated in a recent post that distortion is really bad for
speakers. Why is that?

No, I said _clipping_ is really bad for speakers.

As someone else asked in the other thread, why, then, is the kind of
clipping that is built into nearly all modern CD's, many with some
severity, not damaging to speakers?

What evidence do you have that CDs are clipped ?


It's not clipping, it's excess power. Clipped material, whether from
the amp, or from the source, or wherever has relatively more HF energy
than that which is not clipped which can expose the HF drivers sooner
than non-clipped material. There is no fast rule that clipping will
damage a speaker. It will do so if and only if the amp is delivering
more power than a driver can handle.

Uhuh.

And clipping results in more of the signal power in the HF band.

Simple really.

Graham

"Arny Krueger"

A speaker that is resistant to damage has:

(1) An impedance curve that is high, bumpy and rises dramatically at the
frequency extremes.

(2) Is highly effficient.

(3) Can take a lot of power, and come around looking for more.

(4) Sounds horrid well before the beginnings of destruction.



** Hmmm - sounds like someone is describing a JBL 2482 phenolic horn
driver ........

Or else an Altec 290 .......




........... Phil

William Sommerwerck wrote:

It's not clipping, it's excess power. Clipped material, whether from
the amp, or from the source, or wherever has relatively more HF energy
than that which is not clipped which can expose the HF drivers sooner
than non-clipped material. There is no fast rule that clipping will
damage a speaker. It will do so if and only if the amp is delivering
more power than a driver can handle.

Finally. A sane comment on the subject.

It should say 'in band power'

The dividing network in a multi-way speaker directs HF energy ( as produced
by clipping ) to the tweeter which typically has low thermal capacity.
That's why tweeters are easilt burnt out by clipping.

If we were talking about a single full-range speaker without crossover - the
probability of damage from clipping would be much lower.

Graham

In article .com,
wrote:

that's interesting about ultrasonics and the tweeters "trying hard". i
thought if it was out of the effective band of the driver, the driver
would simply ignore the signal more and more because it can't "see" the
sound at that frequency range. but if i understand you correctly, a
driver might be trying to produce that sound.

Try it with a woofer, where the effect is easier to see. Sweep a tone
back and forth from 10 Hz to 2 KHz and watch what happens to the cone.

When the frequency is too low for the system to handle, you see the
cone break up, and you see massive excursion. When the frequency is
too high, you see a different kind of cone break-up, a lot less movement,
and the voice coil gets hot.

Get some of those $5 8" full-range installed sound drivers and give it
a try. It's lots of fun.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

William Sommerwerck wrote:

It doesn't matter whether the driver "tries" to reproduce the sound, or not.
The voice coil still has to dissipate the power.

If you put 50 watts at 1MHz into a tweeter that can only handle 5 watts, you
_will_ burn it out.

One man's tweeter is another man's inductor.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."