I disagree with the concept that speakers "draw power". An amp clips when it is pushed beyond its limit -- the top of the wave is chopped off.
If I'm wrong, I would like to hear why.
If I'm wrong, I would like to hear why.
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Help me understand the concept of speakers "drawing power"
I guess this question relates to how amplifiers and A/V receiver clip. My question is, what causes amplifiers to clip? People say it is when a speakers demands more power than the amplifier can supply but how does this work? How does a speaker know how much power to demand? I thought speakers simply "play" with the amount of power that is sent from an amplifier or A/V receiver and thus the amplifier or A/V receiver sets how loud it is going to be (with the use of the volume control).
People also say that clipping is more likely at higher volumes. Again, what is causing them to clip at higher volumes? How does the speaker "demand power?"
People also say that clipping is more likely at higher volumes. Again, what is causing them to clip at higher volumes? How does the speaker "demand power?"
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I would like to know too. I have a Monster 5 channel signature amp that would clip with my old 8 ohm Polk towers. My Denon 4308ci has no such issues playing at even higher volumes while watching the old BDs. And I could tell the difference in sound with this amp, much clearer then the Denon, but not by much.
And no Monster bashing please, just want to know why the clip?
And I am not talking above 0db volumes either, well maybe +5db, but why the clip with 8ohm speakers?
Mike
And no Monster bashing please, just want to know why the clip?
And I am not talking above 0db volumes either, well maybe +5db, but why the clip with 8ohm speakers?
Mike
How many watts on the Monster amp? A speaker can clip too. Basically the cone has a limit to its excursion. If the amp tries to push the cone out further than it is physically able to go, it halts abruptly, which is another type of "clipping".
One benefit of pro level speakers, is that they usually have a high dB that can be achieved. Listening to a less capable speaker at a high SPL, can push the speaker beyond its limit.
One benefit of pro level speakers, is that they usually have a high dB that can be achieved. Listening to a less capable speaker at a high SPL, can push the speaker beyond its limit.
Read up on Ohm's Law and you'll have the basics down pretty good.
The receiver/amp is the voltage source, the speaker is the resistance (impedance really, but no need to get complex on the first day at school), and current is developed in the circuit depending on the voltage and resistance.
The resultant current and the voltage determine the power (watts) delivered to the speakers.
When you turn up the volume, you are increasing the voltage to the speakers then current follows the voltage according to the speaker's impedance. It's this combination of voltage and current that determine the watts the speaker is receiving.
The receiver/amp is the voltage source, the speaker is the resistance (impedance really, but no need to get complex on the first day at school), and current is developed in the circuit depending on the voltage and resistance.
The resultant current and the voltage determine the power (watts) delivered to the speakers.
When you turn up the volume, you are increasing the voltage to the speakers then current follows the voltage according to the speaker's impedance. It's this combination of voltage and current that determine the watts the speaker is receiving.
Depends on what people mean by clipping. Frankly, I think the term is often used improperly.
Usually the only time that sort of phraseology is used (correctly) is when, as alluded to by whoaru, impedance is being discussed. A 4ohm load (load is a bit of a misnomer, btw) is more of a draw on an amp than an 8ohm load.
That said, the impedance rating of a speaker is a nominal value. The impedance any one speaker presents is not static. It changes constantly. Goes up and down. A speaker whose impedance is nominally rated at 8ohms may actually drop lower than another speaker whose impedance is also nominally rated at 8ohms. In this case one can say that the speaker whose impedance drops lower is more of a draw on the amp than the other.
That said, the impedance rating of a speaker is a nominal value. The impedance any one speaker presents is not static. It changes constantly. Goes up and down. A speaker whose impedance is nominally rated at 8ohms may actually drop lower than another speaker whose impedance is also nominally rated at 8ohms. In this case one can say that the speaker whose impedance drops lower is more of a draw on the amp than the other.
If the impedance gets high (I am aware it's not a constant), and the music is loud, then the speaker may ask for more current than the amp can produce, and that is when amp clipping occurs. And is why high current amps (like the HK's) don't clip even though they have a low watt rating.
Am I understanding that correctly?
Also, what causes the impedance to swing? Is it the frequency of the music, or another factor?
TIA
Quote:
Originally Posted by whoaru99 /forum/post/16883066
Read up on Ohm's Law and you'll have the basics down pretty good.
The receiver/amp is the voltage source, the speaker is the resistance (impedance really, but no need to get complex on the first day at school), and current is developed in the circuit depending on the voltage and resistance.
The resultant current and the voltage determine the power (watts) delivered to the speakers.
When you turn up the volume, you are increasing the voltage to the speakers then current follows the voltage according to the speaker's impedance. It's this combination of voltage and current that determine the watts the speaker is receiving.
If the impedance gets high (I am aware it's not a constant), and the music is loud, then the speaker may ask for more current than the amp can produce, and that is when amp clipping occurs. And is why high current amps (like the HK's) don't clip even though they have a low watt rating.
Am I understanding that correctly?
Also, what causes the impedance to swing? Is it the frequency of the music, or another factor?
TIA
low
Quote:
Originally Posted by MLKstudios /forum/post/16883391
I never finished my EE degree, so pardon my ignorance.
If the impedance gets high...............
low
OK. If the impedance drops, then more current is demanded.
Yes?
Yes?
Think of impedance as exactly that. You have a wire coming out of an amp (the + strand) and a wire going back to the amp (the - strand). In between is the speaker which has an impedance. The speaker impedes the current. The less it impedes, the more easily (faster?) current can flow through the whole system. The amp will provide current as fast as it can but it has a limit. So, it is not really the amount of current, but how quickly the amp is asked to provide it, or push it, that creates a problem for an amp.
If you remove the speaker and short the wires, that presents zero impedance to an amp. The current is completely unimpeded. And we know what will happen.
Quote:
Originally Posted by MLKstudios /forum/post/16883437
OK. If the impedance drops, then more current is demanded.
Yes?
Think of impedance as exactly that. You have a wire coming out of an amp (the + strand) and a wire going back to the amp (the - strand). In between is the speaker which has an impedance. The speaker impedes the current. The less it impedes, the more easily (faster?) current can flow through the whole system. The amp will provide current as fast as it can but it has a limit. So, it is not really the amount of current, but how quickly the amp is asked to provide it, or push it, that creates a problem for an amp.
If you remove the speaker and short the wires, that presents zero impedance to an amp. The current is completely unimpeded. And we know what will happen.
Its best to use the water analogy is these cases.
* Resistance = the size of the pipe
* Current = the current/pressure of the water
* Voltage = the difference in water pressures between two points.
* Voltage source = water pump
If you raise the water level difference between two points (voltage increase), the pressure of the water flow will increase (current increase). If you do this while the pipes are large (lower resistance) and still want the same pressure your pump will have to pump harder. If you do this while the pipes are small (higher resistance) and you still want the same pressure, your pump will have to work less as hard.
Quote:
Originally Posted by MLKstudios /forum/post/16883437
OK. If the impedance drops, then more current is demanded.
Yes?
Its best to use the water analogy is these cases.
* Resistance = the size of the pipe
* Current = the current/pressure of the water
* Voltage = the difference in water pressures between two points.
* Voltage source = water pump
If you raise the water level difference between two points (voltage increase), the pressure of the water flow will increase (current increase). If you do this while the pipes are large (lower resistance) and still want the same pressure your pump will have to pump harder. If you do this while the pipes are small (higher resistance) and you still want the same pressure, your pump will have to work less as hard.
Speed is not the issue as the current flows as fast a large proportion of the speed of light. I usually say to think of a high impedance/resistance as analogous to a narrow hose and a low impedance/resistance as analogous to a wide diameter hose. For a given pressure, more water (current) will flow through the large hose assuming there is enough water supply. If the diameter is large enough, all the supply will be drained.
Sloppy but that's often the way with analogies. As you said earlier, Ohm's law (V=IR) should be enough. For any V, I and R are inversely proportional.
Quote:
Originally Posted by sivadselim /forum/post/16883541
Think of impedance as exactly that. You have a wire coming out of an amp (the + strand) and a wire going back to the amp (the - strand). In between is the speaker which has an impedance. The speaker impedes the current. The less it impedes, the more easily (faster?) current can flow through the whole system. The amp will provide current as fast as it can but it has a limit. So, it is not really the amount of current, but how quickly the amp is asked to provide it, or push it, that creates a problem for an amp.
If you remove the speaker and short the wires, that presents zero impedance to an amp. The current is completely unimpeded. And we know what will happen.
Speed is not the issue as the current flows as fast a large proportion of the speed of light. I usually say to think of a high impedance/resistance as analogous to a narrow hose and a low impedance/resistance as analogous to a wide diameter hose. For a given pressure, more water (current) will flow through the large hose assuming there is enough water supply. If the diameter is large enough, all the supply will be drained.
Sloppy but that's often the way with analogies. As you said earlier, Ohm's law (V=IR) should be enough. For any V, I and R are inversely proportional.
That speed is not the correct way to think of it is why I wrote "(faster?)" with a question mark.
It is hard to avoid analogies like water in a hose or pipe, but they are faulty. Impedance is not really like pressure in that sort of analogy. A better analogy (IMO) is one of a sink, spigot, and drain. You can set the rate of flow out of a spigot such that the water remains at a certain constant level in a sink. This is, of course, related to the rate at which water drains from the sink. So, if you can "sync" the rate of inflow and outflow, you can keep the water at a constant level. But if you suddenly increase the size of the drain-hole (decrease the impedance) you may or may not be able to turn the spigot up to a high enough rate of output to keep the water in the sink at the same level. If you can't, the impedance is too low (drain-hole is too big).
Quote:
Originally Posted by Kal Rubinson /forum/post/16883595
Speed is not the issue as the current flows as fast a large proportion of the speed of light. I usually say to think of a high impedance/resistance as analogous to a narrow hose and a low impedance/resistance as analogous to a wide diameter hose. For a given pressure, more water (current) will flow through the large hose assuming there is enough water supply. If the diameter is large enough, all the supply will be drained.
Sloppy but that's often the way with analogies. As you said earlier, Ohm's law (V=IR) should be enough. For any V, I and R are inversely proportional.
That speed is not the correct way to think of it is why I wrote "(faster?)" with a question mark.
It is hard to avoid analogies like water in a hose or pipe, but they are faulty. Impedance is not really like pressure in that sort of analogy. A better analogy (IMO) is one of a sink, spigot, and drain. You can set the rate of flow out of a spigot such that the water remains at a certain constant level in a sink. This is, of course, related to the rate at which water drains from the sink. So, if you can "sync" the rate of inflow and outflow, you can keep the water at a constant level. But if you suddenly increase the size of the drain-hole (decrease the impedance) you may or may not be able to turn the spigot up to a high enough rate of output to keep the water in the sink at the same level. If you can't, the impedance is too low (drain-hole is too big).
Of course, impedance is not like pressure. The analog for pressure is voltage. OTOH, I like your analogy.
Quote:
Originally Posted by sivadselim /forum/post/16883604
That speed is not the correct way to think of it is why I wrote "(faster?)" with a question mark.
It is hard to avoid analogies like water in a hose or pipe, but they are faulty. Impedance is not really like pressure in that sort of analogy. A better analogy is one of a sink, spigot, and drain. You can set the rate of flow out of a spigot such that the water remains at a certain constant level in a sink. This is of course related to the rate at which water drains from the sink. So, if you can "sync" the rate of inflow and outflow, you can keep the water at a constant level. But if you suddenly increase the size of the drain-hole (decrease the impedance) you may or may not be able to turn the spigot up to a high enough rate of output to keep the water in the sink at the same level. If you can't, the impedance is too low (drain-hole is too big).
Of course, impedance is not like pressure. The analog for pressure is voltage. OTOH, I like your analogy.
So, OP, clipping is the amp distorting because it can't make any more power. Louder equals more power flowing to the speaker - - this should feel pretty obvious - - you turn up the volume to increase the power you're providing to the speaker.
How loud a particular amp/speaker will be when the amp clips depends on a number of factors, including the speaker's sensitivity (how loud does it get with one watt of power?) the amp's own power limit (eg 100 watts at clipping) and the speaker's impedance, which can be very different at different frequencies.
Since the amp is responding to the input signal, it might be easier to think of it as the input signal exceeding the ability of the amp to amplify without distortion. Amps don't know they are dostorting - - they just keep trying to amplify the signal proportionally, rather than just getting to X power and then refusing to try to amplify any louder input signal.
But the speaker is critical because its sensitivity and impedance control how loud the system will play before distortion.
Easy to search amp clipping and see what it's about. You can find an Ohm's law calculator via google if you just want to play around with how power, impedance, voltage and current interact.
How loud a particular amp/speaker will be when the amp clips depends on a number of factors, including the speaker's sensitivity (how loud does it get with one watt of power?) the amp's own power limit (eg 100 watts at clipping) and the speaker's impedance, which can be very different at different frequencies.
Since the amp is responding to the input signal, it might be easier to think of it as the input signal exceeding the ability of the amp to amplify without distortion. Amps don't know they are dostorting - - they just keep trying to amplify the signal proportionally, rather than just getting to X power and then refusing to try to amplify any louder input signal.
But the speaker is critical because its sensitivity and impedance control how loud the system will play before distortion.
Easy to search amp clipping and see what it's about. You can find an Ohm's law calculator via google if you just want to play around with how power, impedance, voltage and current interact.
Thanks for all the analogies. I can ALMOST remember something similar years ago.
If you don't mind me asking again, what causes the "impedance" in the speaker to change (rise and fall)?
If you don't mind me asking again, what causes the "impedance" in the speaker to change (rise and fall)?
There are two big variables. One is the inductance of the voice coil and the reactances of the crossover. This causes a change in resistance with frequency. Another is heat as a consequence high levels which changes the resistance of many elements.
Quote:
Originally Posted by MLKstudios /forum/post/16884325
Thanks for all the analogies. I can ALMOST remember something similar years ago.
If you don't mind me asking again, what causes the "impedance" in the speaker to change (rise and fall)?
There are two big variables. One is the inductance of the voice coil and the reactances of the crossover. This causes a change in resistance with frequency. Another is heat as a consequence high levels which changes the resistance of many elements.
Appreciate the response Kal. Is it higher or lower frequencies that cause the impedance to drop, or is there no direct relationship?
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