Hello,
I have an audio amp, 40 watts RMS per channel (8 ohm) and I would like
to plug to one channel a small speaker 19 watts (8 ohm).

4 questions:
1- What circuit should I build to adapt?

2- How can I know how much ampere the amp is using to drive one
loudspeaker?

3- A better suitable newsgroup to post this question?

Search on the internet:
4- What words should I use to find some appropriate technical texts?

Thank you.

"Jean" wrote in message
om...
Hello,
I have an audio amp, 40 watts RMS per channel (8 ohm) and I would like
to plug to one channel a small speaker 19 watts (8 ohm).

4 questions:
1- What circuit should I build to adapt?

none. just connect it. The power in your program signal is NOT the full
power of the amplifier.

And after that, if it sounds bad, turn it down.

Unless you plan to pound the amp at clipping levels constantly (i.e., use it
as a guitar amp), there is very little danger of hurting the speaker with
too much power (you're probably more likely to hurt it with too LITTLE
power). If you plan to abuse the volume control (play loud without regard
to how much it is disorting), though, then you may need to watch out.


2- How can I know how much ampere the amp is using to drive one
loudspeaker?

It varies constantly with the program (music, voice, whatever).


3- A better suitable newsgroup to post this question?

Search on the internet:
4- What words should I use to find some appropriate technical texts?

Thank you.

In article ,
"Billw" wrote:

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

--
cyrus

*coughcasaucedoprodigynetcough*

cyrus writes:

In article ,
"Billw" wrote:

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

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, and those high
frequency components can overload the high freuqncy driver
even through the total power to the speaker is much less
than the speaker power rating. The reason for this is
that the high freuqncy driver has typically much lower
power rating then the other drivers on the speaker, because
normal sounds do not have much high frequency signals.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

"Tomi Holger Engdahl" wrote

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

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

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.

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.

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.

"Tomi Holger Engdahl" wrote

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

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

"Tomi Holger Engdahl" wrote

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

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

cyrus writes:

In article ,
"Billw" wrote:

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

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, and those high
frequency components can overload the high freuqncy driver
even through the total power to the speaker is much less
than the speaker power rating. The reason for this is
that the high freuqncy driver has typically much lower
power rating then the other drivers on the speaker, because
normal sounds do not have much high frequency signals.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

cyrus writes:

In article ,
"Billw" wrote:

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

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, and those high
frequency components can overload the high freuqncy driver
even through the total power to the speaker is much less
than the speaker power rating. The reason for this is
that the high freuqncy driver has typically much lower
power rating then the other drivers on the speaker, because
normal sounds do not have much high frequency signals.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

It's not the waveform in and of itself that tweeters are sensitive to. It's
simply the increased high frequency power content. The distinction is
important.

On Wed, 23 Jun 2004 16:56:51 -0400, "MZ"
wrote:

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

It's not the waveform in and of itself that tweeters are sensitive to. It's
simply the increased high frequency power content. The distinction is
important.

A squared-off waveform has added hf. Why is one way of describing it
better?

On Wed, 23 Jun 2004 16:56:51 -0400, "MZ"
wrote:

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

It's not the waveform in and of itself that tweeters are sensitive to. It's
simply the increased high frequency power content. The distinction is
important.

A squared-off waveform has added hf. Why is one way of describing it
better?

On Wed, 23 Jun 2004 16:56:51 -0400, "MZ"
wrote:

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

It's not the waveform in and of itself that tweeters are sensitive to. It's
simply the increased high frequency power content. The distinction is
important.

A squared-off waveform has added hf. Why is one way of describing it
better?

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

It's not the waveform in and of itself that tweeters are sensitive to. It's
simply the increased high frequency power content. The distinction is
important.

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

It's not the waveform in and of itself that tweeters are sensitive to. It's
simply the increased high frequency power content. The distinction is
important.

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

If you're in a position to turn the input (or maybe preamp stage) too
far up in a vain quest for extra volume, it may start clipping, giving
the power amplifier a nasty square-edged waveform to amplify.
Tweeters can succumb to these waveforms rather easily.

In article ,
"Billw" wrote:

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

--
cyrus

*coughcasaucedoprodigynetcough*

In article ,
"Billw" wrote:

(you're probably more likely to hurt it with too LITTLE
power).

How does that happen?

--
cyrus

*coughcasaucedoprodigynetcough*

"Billw" wrote in message ...
"Jean" wrote in message
om...
Hello,
I have an audio amp, 40 watts RMS per channel (8 ohm) and I would like
to plug to one channel a small speaker 19 watts (8 ohm).

4 questions:
1- What circuit should I build to adapt?

none. just connect it. The power in your program signal is NOT the full
power of the amplifier.

And after that, if it sounds bad, turn it down.

Unless you plan to pound the amp at clipping levels constantly (i.e., use it
as a guitar amp), there is very little danger of hurting the speaker with
too much power (you're probably more likely to hurt it with too LITTLE
power). If you plan to abuse the volume control (play loud without regard
to how much it is disorting), though, then you may need to watch out.

Then, what is the purpose to have a loudspeaker (on a HI-FI audio amp)
with enough power to be driven by the amp? ( I use my amp only for
music)

3- A better suitable newsgroup to post this question?

Search on the internet:
4- What words should I use to find some appropriate technical texts?

Jean wrote:

Then, what is the purpose to have a loudspeaker (on a HI-FI audio amp)
with enough power to be driven by the amp? ( I use my amp only for
music)

The key is to understand what the ratings mean.

The speaker is able to withstand 19W of clean signal before it fries.
The amplifier is capable of putting out 40W of power before it blows
up or distorts the signal excessively.

An amplifier that only puts out 10W cleanly will be distorting heavily
at 15W. This is VERY likely to blow up the tweeter in your speakers.
An amp that can put out more than 19W cleanly (in this case, 40W) is
probably NOT going to blow up your speakers at 15W output.

Consider it this way: Your speakers will blow up at 19W with a clean
signal, or sooner with a bad signal.

Something else to consider is that for an average home, 10W continuous
into typical speakers is almost enough to make your ears bleed! 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.

So hook 'em up, and don't worry about it.

"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.

Jean wrote:

Then, what is the purpose to have a loudspeaker (on a HI-FI audio amp)
with enough power to be driven by the amp? ( I use my amp only for
music)

The key is to understand what the ratings mean.

The speaker is able to withstand 19W of clean signal before it fries.
The amplifier is capable of putting out 40W of power before it blows
up or distorts the signal excessively.

An amplifier that only puts out 10W cleanly will be distorting heavily
at 15W. This is VERY likely to blow up the tweeter in your speakers.
An amp that can put out more than 19W cleanly (in this case, 40W) is
probably NOT going to blow up your speakers at 15W output.

Consider it this way: Your speakers will blow up at 19W with a clean
signal, or sooner with a bad signal.

Something else to consider is that for an average home, 10W continuous
into typical speakers is almost enough to make your ears bleed! 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.

So hook 'em up, and don't worry about it.

Jean wrote:

Then, what is the purpose to have a loudspeaker (on a HI-FI audio amp)
with enough power to be driven by the amp? ( I use my amp only for
music)

The key is to understand what the ratings mean.

The speaker is able to withstand 19W of clean signal before it fries.
The amplifier is capable of putting out 40W of power before it blows
up or distorts the signal excessively.

An amplifier that only puts out 10W cleanly will be distorting heavily
at 15W. This is VERY likely to blow up the tweeter in your speakers.
An amp that can put out more than 19W cleanly (in this case, 40W) is
probably NOT going to blow up your speakers at 15W output.

Consider it this way: Your speakers will blow up at 19W with a clean
signal, or sooner with a bad signal.

Something else to consider is that for an average home, 10W continuous
into typical speakers is almost enough to make your ears bleed! 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.

So hook 'em up, and don't worry about it.

Jean wrote:

"Billw" wrote in message ...
"Jean" wrote in message
om...
Hello,
I have an audio amp, 40 watts RMS per channel (8 ohm) and I would like
to plug to one channel a small speaker 19 watts (8 ohm).

4 questions:
1- What circuit should I build to adapt?

none. just connect it. The power in your program signal is NOT the full
power of the amplifier.

And after that, if it sounds bad, turn it down.

Unless you plan to pound the amp at clipping levels constantly (i.e., use it
as a guitar amp), there is very little danger of hurting the speaker with
too much power (you're probably more likely to hurt it with too LITTLE
power). If you plan to abuse the volume control (play loud without regard
to how much it is disorting), though, then you may need to watch out.


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).


Then, what is the purpose to have a loudspeaker (on a HI-FI audio amp)
with enough power to be driven by the amp? ( I use my amp only for
music)


That really is kinda reversed. You want an amp that can produce
clean undistorted power over the range that the speakers are
rated for. It's only a rough reference and does not mean as much
as some sales people would have you think. All things being even,
a 40 watt speaker can be driven to a louder level than a 20 watt
one before it begins to distort (i.e., is being driven beyond its
physical capabilities).

The problem is that things are almost NEVER all even! For
example, if the 40 watt speakers were 3dB less sensitive than the
20 watt ones, driving them at 40 watts would produce the SAME
loudness as driving the 20 watt ones at 20 watts. If you had 100
watt rated headphones and fed 100 watts of audio power into them,
you still couldn't fill a dance hall with music. You could though
with some very efficient speakers such as a horn type design, etc.

Frequently, in order to get extremly "clean" sound from a
speaker, exotic designs are used that can be very inefficient and
have strange reactive characteristics. This has the interesting
effect that on a lower power or moderate quality amplifier, the
exotic (and usually pricey) speaker can sound much worst that
some other bargin bin speaker. It won't start to really sing
until it is coupled with a high quality, highly resolving
amplifier, etc.

The really important thing is, can you get the maximum volume
that you want to listen to out of the speakers with it sounding
clean and without distortion? If you can, then you need an amp
with a higher power rating than the speakers, that will help to
ensure that you will always be sending clean audio to the
speakers. If the amp is MASSIVELY powered compared to the
speakers it just means you might only use a tiny part of your
volume control before things get too loud and start to distort
(or if you have children in the house, the possibility of blowing
the speakers are greater when someone leaves the volume dial at
100% :-).

You pick your speakers for the volume level and distortion free
sound that you want, then make sure your amp can provide
distortion free audio at that level and somewhat above. Your
system should be fine and you need no "adapter" of any sort. In
fact, you don't want anything between the two components that
would affect the sound.


3- A better suitable newsgroup to post this question?



This is not a "Pro" audio group, its a "Recreation-Audio" group
so my opinion is that this one is fine (although it HAS been a
while since I read the charter :-) However, there are also folks
here with very advanced understanding (or some that just THINK
they do :-) so some basic questions can spin off some more
complicated threads. I appreciated the reference to the RANE
article that was mention earlier by someone in this thread. I was
not aware of some of the issues that it addressed.


Search on the internet:
4- What words should I use to find some appropriate technical texts?


Not sure here. You are looking at many different issues when you
start dealing with loudspeakers. E.g., did you know that the 8
ohm rating is only nominal? that actual impeadance can vary from
as low as 4 ohms and go as high as 15,000 ohms depending on the
frequency that the impeadance is being measured at. Some basic
introductory texts on speaker theory might work for you.

Hope this helps some.

- Jeff

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" 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.

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.

Jeff Wiseman wrote in message ...
Jean wrote:

"Billw" wrote in message ...
"Jean" wrote in message
om...
Hello,
I have an audio amp, 40 watts RMS per channel (8 ohm) and I would like
to plug to one channel a small speaker 19 watts (8 ohm).

4 questions:
1- What circuit should I build to adapt?

none. just connect it. The power in your program signal is NOT the full
power of the amplifier.

And after that, if it sounds bad, turn it down.

Unless you plan to pound the amp at clipping levels constantly (i.e., use it
as a guitar amp), there is very little danger of hurting the speaker with
too much power (you're probably more likely to hurt it with too LITTLE
power). If you plan to abuse the volume control (play loud without regard
to how much it is disorting), though, then you may need to watch out.


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).


Then, what is the purpose to have a loudspeaker (on a HI-FI audio amp)
with enough power to be driven by the amp? ( I use my amp only for
music)


That really is kinda reversed. You want an amp that can produce
clean undistorted power over the range that the speakers are
rated for.
...
The really important thing is, can you get the maximum volume
that you want to listen to out of the speakers with it sounding
clean and without distortion?
- Jeff

My situation: I already have a Hi-Fi amp 40 watts. I have extra
loudspeakers 19 watts. I do not want to damage my 19 watts. I am not
concerned about distortion because my guess ( before plugging my 19
watts) is if I put the volume 40 watts at 10/10, I will damage my 19
watts, tweeters probably first than woofers as I understand from the
postings...
The really important thing is getting max volume 10/10 from a kid not
without distortion, but without damaging my 19 watts loudspeakers.
I could try this: plug the 19 watts, take up the volume to 5/10
(20watts?), 6/10 (24 watts?)... 10/10 (40 watts) and see at what level
I blow up the 19 watts speakers?
I wanted to adapt the power so that if a kid turn the volume 10/10,
yes, the 19 watts speakers are still reproducing the sound.
Then I will think about distortion: If I hear distortion, it is
because the loudspeaker is not able to reproduce the music, then
because there is too much power sent to the speaker: therefore, turn
dowm the volume!
A 1 watt speaker is able to reproduce a 1000 watt amp if you do not
turn the volume at 10/10! You have to adapt in some ways ( which is
the first question ) to keep alive the 1 watt speaker. Then I will
think about a clean reproduction of the music...

Jean wrote:
My situation: I already have a Hi-Fi amp 40 watts. I have extra
loudspeakers 19 watts. I do not want to damage my 19 watts. I am not
concerned about distortion because my guess ( before plugging my 19
watts) is if I put the volume 40 watts at 10/10, I will damage my 19
watts, tweeters probably first than woofers as I understand from the
postings...

In general, putting the setting at 10/10 will cause damage on
most systems anyway if left running long enough.


The really important thing is getting max volume 10/10 from a kid not
without distortion, but without damaging my 19 watts loudspeakers.
I could try this: plug the 19 watts, take up the volume to 5/10
(20watts?), 6/10 (24 watts?)... 10/10 (40 watts) and see at what level
I blow up the 19 watts speakers?
I wanted to adapt the power so that if a kid turn the volume 10/10,
yes, the 19 watts speakers are still reproducing the sound.


Ahh! NOW we're getting to the crux of the matter :-) Cranking the
volume up to 100% on most systems will usually result in a
failure given long enough to heat things up. That's why most
people don't do it :-) I once had a 125watt receiver that my 2
year old daughter cranked up all the way when it was off. She
then made the mistake of pushing the power button! I was in the
house as was able to turn it off before any real damage occurred
but I suspect it was close :-) Suggestions for this at the end of
this note:


Then I will think about distortion: If I hear distortion, it is
because the loudspeaker is not able to reproduce the music, then
because there is too much power sent to the speaker: therefore, turn
dowm the volume!


Exactly. If your amp is rated higher than the speakers, in
general when you start to hear distortion, is because the
speakers are being pushed to hard.


A 1 watt speaker is able to reproduce a 1000 watt amp if you do not
turn the volume at 10/10! You have to adapt in some ways ( which is
the first question ) to keep alive the 1 watt speaker. Then I will
think about a clean reproduction of the music...


OK, here's a way to deal with it but it assumes that you can get
to the signal between your preamp and your main amp. The issue is
that you don't want the signal entering the amp to be high enough
to create a damaging level of signal to the speakers. I solved my
problem as followes:

Although I had a receiver at the time, the preamp and power amp
sections were separated by a pair of jumpers on the back. I
removed the jumpers and put a "T-pad" resistor in using a value
so that when my volume level was up all the way, the total volume
in the room was only slightly louder than I normally listened to.
By putting the resistance between the preamp and the main amp, it
prevented the amp itself from being overdriven into distortion
even when the preamp's volume was up all the way. In other words,
even though the main amp was rated for 125 watts, I was
preventing it from getting enough signal to ever reach that level.

I used a pair of T-pads but I also could have just used a stereo
potentiometer (about a 50Kohm unit wired across the output of the
preamp with the common and tap going to the main amp) adjusted to
limit the maximum volume in the room when the preamp's volume was
set to 100%. I had to make them myself as I couldn't find
something off the self. I'm not sure where you might find
something like this pre-built but anyone handly with a soldering
iron could put something like that together real cheap.

- Jeff

Jean wrote:
My situation: I already have a Hi-Fi amp 40 watts. I have extra
loudspeakers 19 watts. I do not want to damage my 19 watts. I am not
concerned about distortion because my guess ( before plugging my 19
watts) is if I put the volume 40 watts at 10/10, I will damage my 19
watts, tweeters probably first than woofers as I understand from the
postings...

In general, putting the setting at 10/10 will cause damage on
most systems anyway if left running long enough.


The really important thing is getting max volume 10/10 from a kid not
without distortion, but without damaging my 19 watts loudspeakers.
I could try this: plug the 19 watts, take up the volume to 5/10
(20watts?), 6/10 (24 watts?)... 10/10 (40 watts) and see at what level
I blow up the 19 watts speakers?
I wanted to adapt the power so that if a kid turn the volume 10/10,
yes, the 19 watts speakers are still reproducing the sound.


Ahh! NOW we're getting to the crux of the matter :-) Cranking the
volume up to 100% on most systems will usually result in a
failure given long enough to heat things up. That's why most
people don't do it :-) I once had a 125watt receiver that my 2
year old daughter cranked up all the way when it was off. She
then made the mistake of pushing the power button! I was in the
house as was able to turn it off before any real damage occurred
but I suspect it was close :-) Suggestions for this at the end of
this note:


Then I will think about distortion: If I hear distortion, it is
because the loudspeaker is not able to reproduce the music, then
because there is too much power sent to the speaker: therefore, turn
dowm the volume!


Exactly. If your amp is rated higher than the speakers, in
general when you start to hear distortion, is because the
speakers are being pushed to hard.


A 1 watt speaker is able to reproduce a 1000 watt amp if you do not
turn the volume at 10/10! You have to adapt in some ways ( which is
the first question ) to keep alive the 1 watt speaker. Then I will
think about a clean reproduction of the music...


OK, here's a way to deal with it but it assumes that you can get
to the signal between your preamp and your main amp. The issue is
that you don't want the signal entering the amp to be high enough
to create a damaging level of signal to the speakers. I solved my
problem as followes:

Although I had a receiver at the time, the preamp and power amp
sections were separated by a pair of jumpers on the back. I
removed the jumpers and put a "T-pad" resistor in using a value
so that when my volume level was up all the way, the total volume
in the room was only slightly louder than I normally listened to.
By putting the resistance between the preamp and the main amp, it
prevented the amp itself from being overdriven into distortion
even when the preamp's volume was up all the way. In other words,
even though the main amp was rated for 125 watts, I was
preventing it from getting enough signal to ever reach that level.

I used a pair of T-pads but I also could have just used a stereo
potentiometer (about a 50Kohm unit wired across the output of the
preamp with the common and tap going to the main amp) adjusted to
limit the maximum volume in the room when the preamp's volume was
set to 100%. I had to make them myself as I couldn't find
something off the self. I'm not sure where you might find
something like this pre-built but anyone handly with a soldering
iron could put something like that together real cheap.

- Jeff