1000w speakers a lie?

[Sx57]

Hello dear memebrs please take a look at this quote:
""Q: Would you consider a design for a 1,000W amplifier?
A: No, I would never consider a 1kW amp. No loudspeaker can handle that much power, regardless of claims. Look at a 1000W electric heater - feel how hot it gets and how quickly. Note that the element is thick resistance wire on a ceramic former. The resistance wire glows red hot after only a few seconds.

Since only about 1% of power is converted to sound, the voicecoil has to do the same work as the electric heater. But look at a voicecoil - it is thin wire on a thin aluminium or Kapton former. At 1kW it may last a few minutes if you are lucky. At low frequencies, the voicecoil will leave the gap, the speaker will distort badly, and quickly fail. In some cases, the spider or surround can be torn, or the voicecoil can suffer impact damage from colliding with the rear pole-piece

Unfortunately, the advertisements and even data sheets lead one to believe that many drivers will take that kind of power. The vast majority will not. I have tested a (claimed) 500W driver that distorted (and would have quickly overheated) with only 100W input. It was a massive affair, having dual voicecoils, dual spiders, dual magnets and double the distortion.

Although it is useful to have headroom in an amp, it is far better to use smaller amps and an electronic crossover. This makes the requirement for 1kW amps simply go away for all domestic hi-fi systems. Having said all this, P117 has been published, but I hope no-one is silly enough to build it ""

Source:sound.westhost.com
This is extracted from the mentioned website's FAQ section.this is one of the most knowledgeable sites I have ever seen about audio,amps,speaker...
As you can see it is clearly stating that it is not possible for a speaker driver to handle 1000w(RMS) power.so how do we have so many speakers with more than 1000w RMS power?
Are the companies lying to us?
Is it just a matter of more sensitive speaker paired with 1000w rms power amp,configured in a way that the driver never uses that 1000w because it will simply fail?(for example there is something similar about qsc k12 compression driver equipped with 500w RMS which obviously will never be used even for milliseconds.)I always wondered that even if a speaker wastes 250w heat,shouldn't it make my room warmer?where does the heat go really?now think about 1000w!man my PC gpu (gtx 970)needs a case with good fans plus it' own fan to waste a lot less heat.so how does the 1000w speaker waste that amount of heat without failing?
What is the truth about the 1000w (or more) speakers?

 

[markw]

Please note that these numbers would most likely be for very short peaks of musical material, not steady tones over a period of time. and, jut because it might be able to absorb that power for a short period, nowhere does it say it wouldn't sound like ash while doing so.

And, electric heaters absorb that power for extended periods of time to generate heat. That's what they are made for. Speakers aren't.

Aln0g that line, we could truthfully say that a human can fun at speeds of 28 miles per hour. Unless your name is Barry Allen, I doubt you could keep it up for long.

Humans could perhaps run as fast 40 mph, a new study suggests. Such a feat would leave in the dust the world's fastest runner, Usain Bolt, who has clocked nearly 28 mph in the 100-meter sprint. - See more at: http://www.livescience.com/8039-humans-run-40-mph-theory.html#sthash.ktkxAOoC.dpuf

 

[Swerd]

Please note that these numbers would most likely be for very short peaks of musical material, not steady tones over a period of time. and, jut because it might be able to absorb that power for a short period, nowhere does it say it wouldn't sound like ash while doing so.

I completely agree with Mark.

All amplifier power ratings are made with a time factor in mind. Some ratings are estimated over very short times, essentially a fraction of a second, and others are an average power over several minutes. Often these time spans are not directly stated, and I think that is the major reason why people get confused. For any amplifier, a short time span leads to a higher wattage rating, and a longer time span leads to lower wattage value.

That's why comparing different types of wattage ratings (with their different time frames) can be meaningless, like comparing apples & oranges. However if you compare the wattage ratings of two different amps, that are estimated by the same method, such as Federal Trade Commission (FTC) required continuous watts calculated by the root mean square (RMS) method, it becomes useful.

As far as a speaker's ability to handle high power, as the OP pointed out, too much sustained high power will cause some part of a driver to fail. There are some large PA speakers that are built to handle very high power levels, for much longer times, than small hifi speakers made for indoor use. But there is also a wide range between the minimum power required for a speaker to sound good, and the upper power limit before a speaker goes into thermal failure. That's why a single power rating for a speaker doesn't mean much.

 

[Sx57]

Thanks.that's why I wanted to know if speaker could take 1000w RMS not peak.after all RMS is used for continuous not just a few seconds.i believe your are right.take a look at these speakers for example:zxa 5 from EV company and dsr115 by Yamaha.both of them mention 1000w continuous RMS.seems the companies are lying by giving amp RMS power implying that the speaker can take them continuously.now according the what is mentioned in previous post,no speaker can take such amount of power.

 

[Swerd]

I always assume a speaker manufacturer's power rating talks about the power at which thermal failure takes place. They usually try to test for that or estimate it. It says nothing about the power level you might want to use when listening to those speakers.

 

[TLS Guy]

Everything you say is basically correct. High power and good is an expensive proposition. The problem is that there is no accepted standard of how long the RMS signal has to be applied. Yes, a speaker voice coil can become and electric fire.

Things that make for high power drivers, are flattened edge wound voice coils with a very narrow VC gap so that the magnet acts as a heat sink. In addition the cone moving creates air motion and with a vented gap removes heat.

Even if the VC does not fry it still heats and causes dynamic thermal compression. There is strength in numbers. I use 10" drivers with an Fs of 20 Hz. Those four VCs in my view are better then two 15" or one 18".

The big problem though is not the woofers, it is the midrange. There are huge power demands from 80 Hz to 2.5 KHz and sometimes above. The drivers have to be smaller and move a lot less. That is the real trouble range for the realistic reproduction of music.

Tweeter can use ferro fluid to conduct heat to the magnet pole pieces. I do not believe that adversely affects performance, in fact the reverse. The fluid damping lowers Fs and lowers Q.

The real question becomes why to we have monster amps? Floyd Toole alluded to this a few weeks ago here and it is mentioned in the article you site. The reason is incompetently designed speakers, especially high priced passive three way speakers. These speakers often have passive crossovers below 350 Hz and often around 100 Hz. This frequently results in resonance, with voltage and current 45 degrees out of phase, and impedance drops lower than the DC resistance of the bass drivers! Believe me there are plenty of those. They are lousy speakers with a horrid bass and lots of distortion. The golden eared audiophools still often lavish huge praise on them and run off at the mouth with hyperbole. Then of course they have the excuse to was eloquent about which welding amp is best suited to drive the monstrosity.

This brings me to the next point. Only active designs deliver all power to the VC. In passive speakers at least half and often more of the power is lost in the crossover and these can and do burn out in these high powered passive monstrosities.

In my view for ANY three way to be considered a state of the art reference speaker it needs to be fully active or at least active in crossovers below 2 KHz. I am quite definite on that point.

Really that means that for domestic purposes a power of 100 to 200 watts per VC below 2 KHz is plenty. On my mains I have three amps of 250 watts each spread between four VC below 2.5 KHz. So that is 175 watts per VC and everything coasts and is nice and relaxed.

 

[Sx57]

I always assume a speaker manufacturer's power rating talks about the power at which thermal failure takes place. They usually try to test for that or estimate it. It says nothing about the power level you might want to use when listening to those speakers.

So do you mean that if a speaker like zxa5 is rated continuous 1000w RMS,it will fail at 1000w used?
Shouldn't RMS be the actual power rate we can trust?

 

[Swerd]

So do you mean that if a speaker like zxa5 is rated continuous 1000w RMS,it will fail at 1000w used?

Yes

Shouldn't RMS be the actual power rate we can trust?

Don't place your trust in a single power rating for a speaker. There are too many variables that change from owner to owner.

 

[Sx57]

Everything you say is basically correct. High power and good is an expensive proposition. The problem is that there is no accepted standard of how long the RMS signal has to be applied. Yes, a speaker voice coil can become and electric fire.

Things that make for high power drivers, are flattened edge wound voice coils with a very narrow VC gap so that the magnet acts as a heat sink. In addition the cone moving creates air motion and with a vented gap removes heat.

Even if the VC does not fry it still heats and causes dynamic thermal compression. There is strength in numbers. I use 10" drivers with an Fs of 20 Hz. Those four VCs in my view are better then two 15" or one 18".

The big problem though is not the woofers, it is the midrange. There are huge power demands from 80 Hz to 2.5 KHz and sometimes above. The drivers have to be smaller and move a lot less. That is the real trouble range for the realistic reproduction of music.

Tweeter can use ferro fluid to conduct heat to the magnet pole pieces. I do not believe that adversely affects performance, in fact the reverse. The fluid damping lowers Fs and lowers Q.

The real question becomes why to we have monster amps? Floyd Toole alluded to this a few weeks ago here and it is mentioned in the article you site. The reason is incompetently designed speakers, especially high priced passive three way speakers. These speakers often have passive crossovers below 350 Hz and often around 100 Hz. This frequently results in resonance, with voltage and current 45 degrees out of phase, and impedance drops lower than the DC resistance of the bass drivers! Believe me there are plenty of those. They are lousy speakers with a horrid bass and lots of distortion. The golden eared audiophools still often lavish huge praise on them and run off at the mouth with hyperbole. Then of course they have the excuse to was eloquent about which welding amp is best suited to drive the monstrosity.

This brings me to the next point. Only active designs deliver all power to the VC. In passive speakers at least half and often more of the power is lost in the crossover and these can and do burn out in these high powered passive monstrosities.

In my view for ANY three way to be considered a state of the art reference speaker it needs to be fully active or at least active in crossovers below 2 KHz. I am quite definite on that point.

Really that means that for domestic purposes a power of 100 to 200 watts per VC below 2 KHz is plenty. On my mains I have three amps of 250 watts each spread between four VC below 2.5 KHz. So that is 175 watts per VC and everything coasts and is nice and relaxed.

Thank you for your explanation.
So am I right in concluding that no speaker driver can take long continuous RMS power (at least 2 hours)? the reason I ask is that I see a lot of pa speakers claiming big powers which are also bi amped.for example Yamaha DSR 115 or EV zxa5.I always wonder how in hell these speakers can waste such heat!where all the heat goes? My PC has a gtx 970which needs a good amount of fans plus it's own to waste much less heat than 1000ws.how such speakers could waste such heat?shouldn't a 250w real RMS pa speaker warm my house like a 230w heater really? I have 2 behringer 115d which are 250w RMS(I am guessing 1000w peak must be 250w at most optimistically) at max and db sub808d(500w rms) in my house and even when I am pushing them,I feel no heat or increasd heat in my house or even near the speakers.man where is the heat then?

 

[Sx57]

Yes
Don't place your trust in a single power rating for a speaker. There are too many variables that change from owner to owner.

Thank you for kindly answering mate

 

[BoredSysAdmin]

Thank you for your explanation.
So am I right in concluding that no speaker driver can take long continuous RMS power (at least 2 hours)?

Generalizing is a bad habit:
http://reactionaudio.com/Gamma-21_p_36.html
is shipped with 2400W RMP amp. I am fairly confident that it's driver could take continuous 1000W rms power , but not sure you could
another one:
http://www.deepseasound.com/products/mariana-24sr-24-subwoofer
this one has 4k amp

 

[highfigh]

Thank you for your explanation.
So am I right in concluding that no speaker driver can take long continuous RMS power (at least 2 hours)? the reason I ask is that I see a lot of pa speakers claiming big powers which are also bi amped.for example Yamaha DSR 115 or EV zxa5.I always wonder how in hell these speakers can waste such heat!where all the heat goes? My PC has a gtx 970which needs a good amount of fans plus it's own to waste much less heat than 1000ws.how such speakers could waste such heat?shouldn't a 250w real RMS pa speaker warm my house like a 230w heater really? I have 2 behringer 115d which are 250w RMS(I am guessing 1000w peak must be 250w at most optimistically) at max and db sub808d(500w rms) in my house and even when I am pushing them,I feel no heat or increasd heat in my house or even near the speakers.man where is the heat then?

The heat released by most speakers isn't enough to feel unless you actually touch the voice coil or the magnet, but only touch gives a quick result. The voltage across the VC will change as the coil wire becomes warmer, so it's possible to measure that but if a magnet becomes warmer, it's from radiation, not conduction.

Also, the comments about a heater completely ignore thee fact that the wire used in that application is chosen specifically because it does become hot AND survives many heating/cooling cycles. The ceramic is only there for thermal isolation. The wire gauge and composition have everything to do with the amount of heat generated by the coil, at whatever voltage and current are present. Copper or aluminum wire around an aluminum VC with a vented magnet and pole piece are used for allowing heat to be removed and a heater (or toaster) are designed to radiate for a specific purpose, not move a cone because it's immersed in a magnetic field.

One Btu is the amount of work needed to raise the temperature of one pound of water by one degree Fahrenheit and air is a better insulator than conductor, so you won't feel much from your speaker. Another reason is, as Mark mentioned, passive crossovers waste energy, so 3dB insertion loss equates to halving the power.

Speakers and amplifiers for large-venue PA use do handle more power, but they never use passive crossovers because power wasted = money wasted. Heavy power amp or speaker weight also means it costs a lot more to transport the rig.

Then, there's the question of how much power someone actually needs. In a small room, no system really needs to be able to develop 1000w unless the speakers are monstrously insensitive and that is called 'bad system design'. Even in a large space, it's far better to use more speakers with each receiving a few Watts than trying to cover the whole place with a stack on each side of a stage, blasting those who are closest and leaving those in the back corners relatively unaffected.

 

[TLS Guy]

Thank you for your explanation.
So am I right in concluding that no speaker driver can take long continuous RMS power (at least 2 hours)? the reason I ask is that I see a lot of pa speakers claiming big powers which are also bi amped.for example Yamaha DSR 115 or EV zxa5.I always wonder how in hell these speakers can waste such heat!where all the heat goes? My PC has a gtx 970which needs a good amount of fans plus it's own to waste much less heat than 1000ws.how such speakers could waste such heat?shouldn't a 250w real RMS pa speaker warm my house like a 230w heater really? I have 2 behringer 115d which are 250w RMS(I am guessing 1000w peak must be 250w at most optimistically) at max and db sub808d(500w rms) in my house and even when I am pushing them,I feel no heat or increasd heat in my house or even near the speakers.man where is the heat then?

There is no speaker on earth that will take a continuous 1000 watt sine wave for more than a few seconds period. Fortunately real world signals are nothing like a continuous sine wave usually. Although synths used improperly are well known speaker destroyers.

 

[Sx57]

The heat released by most speakers isn't enough to feel unless you actually touch the voice coil or the magnet, but only touch gives a quick result. The voltage across the VC will change as the coil wire becomes warmer, so it's possible to measure that but if a magnet becomes warmer, it's from radiation, not conduction.

Also, the comments about a heater completely ignore thee fact that the wire used in that application is chosen specifically because it does become hot AND survives many heating/cooling cycles. The ceramic is only there for thermal isolation. The wire gauge and composition have everything to do with the amount of heat generated by the coil, at whatever voltage and current are present. Copper or aluminum wire around an aluminum VC with a vented magnet and pole piece are used for allowing heat to be removed and a heater (or toaster) are designed to radiate for a specific purpose, not move a cone because it's immersed in a magnetic field.

One Btu is the amount of work needed to raise the temperature of one pound of water by one degree Fahrenheit and air is a better insulator than conductor, so you won't feel much from your speaker. Another reason is, as Mark mentioned, passive crossovers waste energy, so 3dB insertion loss equates to halving the power.

Speakers and amplifiers for large-venue PA use do handle more power, but they never use passive crossovers because power wasted = money wasted. Heavy power amp or speaker weight also means it costs a lot more to transport the rig.

Then, there's the question of how much power someone actually needs. In a small room, no system really needs to be able to develop 1000w unless the speakers are monstrously insensitive and that is called 'bad system design'. Even in a large space, it's far better to use more speakers with each receiving a few Watts than trying to cover the whole place with a stack on each side of a stage, blasting those who are closest and leaving those in the back corners relatively unaffected.

Thanks .now I understand why speaker's heat doesn't affect my house(or surrounding).my speakers are bi amped by the way.

There is no speaker on earth that will take a continuous 1000 watt sine wave for more than a few seconds period. Fortunately real world signals are nothing like a continuous sine wave usually. Although synths used improperly are well known speaker destroyers.

Thanks for clarification.

Generalizing is a bad habit:
http://reactionaudio.com/Gamma-21_p_36.html
is shipped with 2400W RMP amp. I am fairly confident that it's driver could take continuous 1000W rms power , but not sure you could
another one:
http://www.deepseasound.com/products/mariana-24sr-24-subwoofer
this one has 4k amp

Thanks for the examples mate but I seriously doubt there is any speaker driver that can take 1000w RMS for 2 hours,let alone more watts!

 

[Irvrobinson]

The real question becomes why to we have monster amps? Floyd Toole alluded to this a few weeks ago here and it is mentioned in the article you site. The reason is incompetently designed speakers, especially high priced passive three way speakers. These speakers often have passive crossovers below 350 Hz and often around 100 Hz. This frequently results in resonance, with voltage and current 45 degrees out of phase, and impedance drops lower than the DC resistance of the bass drivers! Believe me there are plenty of those. They are lousy speakers with a horrid bass and lots of distortion. The golden eared audiophools still often lavish huge praise on them and run off at the mouth with hyperbole. Then of course they have the excuse to was eloquent about which welding amp is best suited to drive the monstrosity.

This brings me to the next point. Only active designs deliver all power to the VC. In passive speakers at least half and often more of the power is lost in the crossover and these can and do burn out in these high powered passive monstrosities.

In my view for ANY three way to be considered a state of the art reference speaker it needs to be fully active or at least active in crossovers below 2 KHz. I am quite definite on that point.

Really that means that for domestic purposes a power of 100 to 200 watts per VC below 2 KHz is plenty. On my mains I have three amps of 250 watts each spread between four VC below 2.5 KHz. So that is 175 watts per VC and everything coasts and is nice and relaxed.

Here you go again. Speakers with a crossover at 120Hz can't be any good, except that several expensive ones do sound very good, including at least one developed under the watchful eye of Toole. None of these I've listened to have "horrid bass and lots of distortion". The KEF 207/2 is one of the best speakers I've ever heard, and it has neither of these attributes, and it has a 120Hz crossover. On the other hand, the B&W 800D, which has one of the supposedly more correct 350Hz crossovers, doesn't sound as good overall, and doesn't have smoother or better bass. The Revel Salon2 (with a 120Hz crossover) sounds virtually identical to the smaller Studio2, which has a crossover nearly an octave higher. Do any of these speakers sound as good as your custom TLs? I don't know, having never heard your TLs, but I do know that none of them sound "horrid" or have "high distortion".

I also know that selling 300-600W/ch/4ohm amplifiers is a lot easier than selling active speakers. These amps are not even all that expensive any more. Not that I have anything against active speakers, I'm considering a pair for my next purchase, but limiting oneself to some hypothetically better approach is ill-advised, if others can produce good results.

You'd have a lot more credibility if you stopped talking in absolutes, hyperbole (which is odd, when you accuse audiophiles of the same thing), and drawing conclusions easily disproven by simple listening. You're better than this.

 

[everettT]

Read the write up on this driver, 70+ volts applied and the amp ran out of steam

http://www.data-bass.com/data?page=system&id=130&mset=142

 

[herbu]

Shouldn't RMS be the actual power rate we can trust?

To me, RMS is even more ambiguous than peak.
An RMS measurement can be made over a period of milliseconds or days. I don't ever recall seeing a spec that specifies the time period over which they took their RMS measurement.

I consider "peak" as instantaneous. Something tells me they don't use square waves.

So as mentioned, I consider power ratings of amps and speakers to be more of a neighborhood than a specification.

 

[Sx57]

Read the write up on this driver, 70+ volts applied and the amp ran out of steam

http://www.data-bass.com/data?page=system&id=130&mset=142

Thanks for the input?impressive performance.do you know how long the max long term test implies?can the speaker take a sine wave for about 2 hours at 70+ volts?

 

[Sx57]

To me, RMS is even more ambiguous than peak.
An RMS measurement can be made over a period of milliseconds or days. I don't ever recall seeing a spec that specifies the time period over which they took their RMS measurement.

I consider "peak" as instantaneous. Something tells me they don't use square waves.

So as mentioned, I consider power ratings of amps and speakers to be more of a neighborhood than a specification.

Yeah man.the specs for most speakers seem to be for magicians who know the spell needed to actually push the drivers as hard as claimed.

 

[markw]

Yeah man.the specs for most speakers seem to be for magicians who know the spell needed to actually push the drivers as hard as claimed.

No, they are a guide for people with common sense to get an idea of what their speakers can realistically handle in real world situations.

Can you run at 28 mph for an extended period of time?