"Mercury" wrote in message
news
take a very very low frequency clipping sine wave and power the speaker
with
it.... I dare you to tell me it wont damage it, the reason it gets damaged
is that the wave spends too much time on one side of 0 (DC)

Why do you keep referencing this as DC? Let me show you what DC is again...

__________________________________________________ ___

There, that is DC, does that confuse you?

It would also seem that you think that the ONLY means of cooling a driver is
by cone motion, which is just not true. See Marks post for a great
explanation on this.

at low
frequencies it is a varying DC wave until that wave crosses 0 then it can
be
called an AC wave....

There is no such thing as a DC wave. It does not exist, in theory or
practice. You cannot have a DC wave. DC, by it's very definition, cannot be
a wave. It's AC, whether it is clipped or not.


I see where people come up with the thought that I have fallible
thinking..
maybe i do.. thats why im here to maybe fix that

So tell me why its so important for people not to clip?


Go to google. Search my name and soundfreak03 as authors, you will find many
many threads and hundreds of posts to answer that question.


I play some loud music... its ok for me to blast it? even if its
clipping? It just wont sound as good....

It won't sound good, and it could damage drivers, but NOT because of
clipping or DC. The reason damage occurs is simply too much power. A clipped
amp delivers more power.


By the way give the speaker an ac sine wave at a low frequency that is
clipping and I dare you to proce the cone doesnt move... at that time it
is like pure DC at one Level the most extreme case take 1Hz or .5Hz
or
heck.... .1Hz

Let us get back to reality on this. This is what is know on the usenet as a
red herring. And no the cone isnt going to stop moving, it may go very slow,
as it should, but it won't stop moving. Research inductance.


now tell me that doesnt damage a speaker and ill gladly walk away laughing

Did you deliver more power than the driver could handle or exceed it's
mechanical limits? If NO then it won't damage the speaker. But then again
it's not even related in any way to the real world so why bother with it.


A good meter is what i used a fluke 87 on DC mode you can watch it toggle
any time the frequency is less then about 50 - 60hz

It toggles too quickly to get a reading of course.... but it does toggle
to get the average dc value a needle meter should be hooked up and the
average of the deflection should be 0.... try it with a digital it
doesnt work as well until you get a high enough frequency

I suppose my points may be fallible i admit it..

But tell me why severe clipping is ok for a speaker then I can power my
speakers more without damaging themn

Noone said it was ok. We just said it won't produce DC. It will sound bad
and can potentially deliver more power than the speaker can handle.


Also please do tell how to set up a head unit and amplifier to make so i
dont over power my speakers


Easy, don't turn it up too loud! It's called discipline to know when you
need to turn it down.

But as far as setting gains, here is a link for you to follow.

http://www.installer.com/tech/gains.html

This is to MZ and Les...

Thank you both for clarifying things... a few more questions however:


"MZ" wrote in message
...
take a very very low frequency clipping sine wave and power the speaker
with
it....

If by "very very low frequency" you mean around 1Hz, as your earlier
example
mentioned, then it doesn't matter whether or not the wave is clipping.
It's
still going to impede the air flow dynamic. But why do you insist on
bringing up examples that have no basis in the real world?

I dare you to tell me it wont damage it, the reason it gets damaged
is that the wave spends too much time on one side of 0 (DC)

Who cares if it spends too much time on one side? It's really not as
devastating as you would think. In fact, it may be BETTER that it's
clipped
because then forced air convection becomes a bigger factor by actively
pushing air into and out of the gap, whereas a 1Hz sine wave doesn't do
this
all too well. And if the excursion of the voice coil is not greater than
the voice coil length, the dispersion of heat over a given area will be
wider also under the clipped condition than under the sine condition. In
short, I wouldn't be surprised in the least if the 1Hz sine wave blew the
speaker before the 1Hz square wave did.

at low
frequencies it is a varying DC wave until that wave crosses 0 then it
can
be
called an AC wave....

"DC wave" is an oxymoron. It's either AC or DC. You can't selectively
pick
a part of a wave and say it's DC. The FACT (again, this is fact, not
opinion - and it can be backed by any introductory electronics textbook)
is
that a square wave is an AC wave with no DC component to it.

What do you call a signal that goes from 0V to +10 on and off... like a
square wave but (use an ideal diode) keeping only the positive portion...
this is what i consider to be a DC wave... it cannot be AC because AC must
cross 0 by definition (0 or some reference)



I see where people come up with the thought that I have fallible
thinking..
maybe i do.. thats why im here to maybe fix that

So tell me why its so important for people not to clip?

This has been covered in great detail in this newsgroup. Do a google
search. In short, clipping does two things: 1) it increases the overall
power content of the signal; and 2) it introduces high frequency harmonics
which therefore increases the power content of the high frequency portion.
Note that both reasons for concern have to do with excess power. So, a 50
watt amp can actually theoretically produce 100 watts (the power content
of
a square wave is double that of a sine wave) when fully clipped. It never
quite gets to 100 watts because of the output impedance of the amplifier,
but it's important to recognize that the power does in fact increase.
Tweeters are especially prone to being blown when clipping because this
increase in power tends to reside in the higher frequency portions of the
spectrum, because as I pointed out earlier, a square wave is composed of a
fundamental frequency and a series of odd-order harmonics.

Thats what i was looking for thank you...

A good meter is what i used a fluke 87 on DC mode you can watch it
toggle
any time the frequency is less then about 50 - 60hz

It toggles too quickly to get a reading of course.... but it does
toggle
to get the average dc value

There is no such thing as an "average DC value". If the value is varying
such that you need to take the average, then it's AC by definition. I
think
you need to pick up a physics textbook so you can see how AC and DC are
defined.

There is a such thing as average DC value... the average dc value for a
120V sine wave at 60Hz is 0 The rms value for a 120V 60hz sine wave is 170

this is what I was tought anyway maybe the school i went to was wrong...

Also please do tell how to set up a head unit and amplifier to make so i
dont over power my speakers

I am using an alpine MRV-540F 100W X 4 rms output

i am using infinty kappa 100W 5x7 speakers

using a sony mp3 player.... as a head unit
whats the best way to set up the headunit and the amp... i can use
the
sine wave until it distorts again just tell me how to make the signal
using
cooledit... thats what i use..

I wouldn't use Cool Edit to do it. Use your ears and a couple CDs. You
need to set the gain so that you can listen to the quietest CD you own at
full output power. As you can see, if you use a 0dB signal to set the
gains, then you'll never be able to get your quiet CDs to play at full
volume.

"Mercury" wrote in message news:...
This is to MZ and Les...

Thank you both for clarifying things... a few more questions however:


"MZ" wrote in message
...
take a very very low frequency clipping sine wave and power the
speaker
with
it....

If by "very very low frequency" you mean around 1Hz, as your earlier
example
mentioned, then it doesn't matter whether or not the wave is clipping.
It's
still going to impede the air flow dynamic. But why do you insist on
bringing up examples that have no basis in the real world?

I dare you to tell me it wont damage it, the reason it gets damaged
is that the wave spends too much time on one side of 0 (DC)

Who cares if it spends too much time on one side? It's really not as
devastating as you would think. In fact, it may be BETTER that it's
clipped
because then forced air convection becomes a bigger factor by actively
pushing air into and out of the gap, whereas a 1Hz sine wave doesn't do
this
all too well. And if the excursion of the voice coil is not greater
than
the voice coil length, the dispersion of heat over a given area will be
wider also under the clipped condition than under the sine condition.
In
short, I wouldn't be surprised in the least if the 1Hz sine wave blew
the
speaker before the 1Hz square wave did.

at low
frequencies it is a varying DC wave until that wave crosses 0 then it
can
be
called an AC wave....

"DC wave" is an oxymoron. It's either AC or DC. You can't selectively
pick
a part of a wave and say it's DC. The FACT (again, this is fact, not
opinion - and it can be backed by any introductory electronics textbook)
is
that a square wave is an AC wave with no DC component to it.

What do you call a signal that goes from 0V to +10 on and off... like a
square wave but (use an ideal diode) keeping only the positive portion...
this is what i consider to be a DC wave... it cannot be AC because AC
must
cross 0 by definition (0 or some reference)



I see where people come up with the thought that I have fallible
thinking..
maybe i do.. thats why im here to maybe fix that

So tell me why its so important for people not to clip?

This has been covered in great detail in this newsgroup. Do a google
search. In short, clipping does two things: 1) it increases the overall
power content of the signal; and 2) it introduces high frequency
harmonics
which therefore increases the power content of the high frequency
portion.
Note that both reasons for concern have to do with excess power. So, a
50
watt amp can actually theoretically produce 100 watts (the power content
of
a square wave is double that of a sine wave) when fully clipped. It
never
quite gets to 100 watts because of the output impedance of the
amplifier,
but it's important to recognize that the power does in fact increase.
Tweeters are especially prone to being blown when clipping because this
increase in power tends to reside in the higher frequency portions of
the
spectrum, because as I pointed out earlier, a square wave is composed of
a
fundamental frequency and a series of odd-order harmonics.

Thats what i was looking for thank you...

A good meter is what i used a fluke 87 on DC mode you can watch it
toggle
any time the frequency is less then about 50 - 60hz

It toggles too quickly to get a reading of course.... but it does
toggle
to get the average dc value

There is no such thing as an "average DC value". If the value is
varying
such that you need to take the average, then it's AC by definition. I
think
you need to pick up a physics textbook so you can see how AC and DC are
defined.

There is a such thing as average DC value... the average dc value for a
120V sine wave at 60Hz is 0 The rms value for a 120V 60hz sine wave is
170

this is what I was tought anyway maybe the school i went to was wrong...

Also please do tell how to set up a head unit and amplifier to make so
i
dont over power my speakers

I am using an alpine MRV-540F 100W X 4 rms output

i am using infinty kappa 100W 5x7 speakers

using a sony mp3 player.... as a head unit
whats the best way to set up the headunit and the amp... i can use
the
sine wave until it distorts again just tell me how to make the signal
using
cooledit... thats what i use..

I wouldn't use Cool Edit to do it. Use your ears and a couple CDs. You
need to set the gain so that you can listen to the quietest CD you own
at
full output power. As you can see, if you use a 0dB signal to set the
gains, then you'll never be able to get your quiet CDs to play at full
volume.

What do you call a signal that goes from 0V to +10 on and off... like a
square wave but (use an ideal diode) keeping only the positive portion...
this is what i consider to be a DC wave... it cannot be AC because AC
must
cross 0 by definition (0 or some reference)

Ah, in that case it's an AC wave with a DC component. Since it alternates
about 5 volts, the DC component is 5 volts. The AC component is a 5v
amplitude square wave (+5v to -5v). Add the two together and you come up
with the 0 to 10v square wave that you describe. Waves can be described by
the linear combination of sine wave components. In other words:

complex waveform = sine1 + sine2 + sine3 + sine4 + ...

Each of those sine waves listed above has a different frequency. If "sine1"
happens to be 0 Hz, then it's the DC component of the signal. The fourier
transform of a signal basically tells you what all these sine wave
components are.


There is a such thing as average DC value... the average dc value for a
120V sine wave at 60Hz is 0 The rms value for a 120V 60hz sine wave is
170

this is what I was tought anyway maybe the school i went to was wrong...

Wouldn't be a first. Colege professors certainly aren't perfect, and high
school teachers are even more prone to err.

so are you some kind of engineer or something or this is all just a hobby or
both?

Just wondering where i am entrusting my newly found knoladge

kenny

as you can see im not an english major
"MZ" wrote in message
...
What do you call a signal that goes from 0V to +10 on and off... like a
square wave but (use an ideal diode) keeping only the positive
portion...
this is what i consider to be a DC wave... it cannot be AC because AC
must
cross 0 by definition (0 or some reference)

Ah, in that case it's an AC wave with a DC component. Since it alternates
about 5 volts, the DC component is 5 volts. The AC component is a 5v
amplitude square wave (+5v to -5v). Add the two together and you come up
with the 0 to 10v square wave that you describe. Waves can be described
by
the linear combination of sine wave components. In other words:

complex waveform = sine1 + sine2 + sine3 + sine4 + ...

Each of those sine waves listed above has a different frequency. If
"sine1"
happens to be 0 Hz, then it's the DC component of the signal. The fourier
transform of a signal basically tells you what all these sine wave
components are.


There is a such thing as average DC value... the average dc value for a
120V sine wave at 60Hz is 0 The rms value for a 120V 60hz sine wave is
170

this is what I was tought anyway maybe the school i went to was wrong...

Wouldn't be a first. Colege professors certainly aren't perfect, and high
school teachers are even more prone to err.

so are you some kind of engineer or something or this is all just a hobby
or
both?

Just wondering where i am entrusting my newly found knoladge

I have a degree in engineering, but I wouldn't necessarily call myself an
engineer. But you shouldn't put your faith in what someone says simply
because of the degree they hold or their profession.

absolutely true
"MZ" wrote in message
...
so are you some kind of engineer or something or this is all just a
hobby
or
both?

Just wondering where i am entrusting my newly found knoladge

I have a degree in engineering, but I wouldn't necessarily call myself an
engineer. But you shouldn't put your faith in what someone says simply
because of the degree they hold or their profession.