How much power do your speakers need? Is low power or high power amp more dangerous?

[PENG]

As ADTG knows, I would have responded "it depends..". He got me cornered, though not completely, by specifying the wattage ranges and narrowed down the user to an idiot. Not completely corned, I could have insisted on the "it depends.." response (no choice though) but I answered yes anyway, reluctantly.

I was a little reluctant because of at least two points:

1) He didn't provide the specs of the speakers. Example: For some speakers, the tweeter is the weak link but as @TLS Guy mentioned, the mid range could also be more prone! So that depends..

2) Some idiots are worse than others. I think we can agree on that, so how much of such an idiot needs to be specified too. Example: An idiot may be forced to turn the volume down when he/she can no longer stand the high level of distortions. In that case, the 50-100 W amp for sure won't pose as much danger even if @ADTG confine his poll question to tweeters than can only handle 20 W average, but if this idiot is one that could withstand extremely high levels of distortions and insist on maxing out spl, then the 500-1000 W is definitely more dangerous, even for tweeters rated 150 W "program power".

For those who typically make blanket statements, just one more food for thought kind of point:

A clipped signal, in an extreme case may even look like a square wave, even then, the harmonics that make up the near square wave are always going to be perfect sine waves that have magnitudes below that of the fundamental frequency. Depending on the contents of the media being played, the harmonics resulted from clipping would vary greatly and therefore the point of danger for the individual bass, mid range, high frequency driver will also vary greatly. The same idiot may blow his tweeter one day using the 50 W amp, and blow the mid range on another day when using the 500 W amp. That idiot may even blow the woofer, yet on another day.

I answered yes, but it really still depends, though to a lesser extent given the choices by this particular poll.

 

[snakeeyes]

So clipping is a surge of energy equivalent to all the amps power? This happens because the amp is underpowered? Or why?

 

[Out-Of-Phase]

https://en.wikipedia.org/wiki/Clipping_(audio)

 

[snakeeyes]

https://en.wikipedia.org/wiki/Clipping_(audio)

So seems like a lower powered amp would be more likely to clip. Or am I missing something? Sorry for the newbie questions.

 

[PENG]

So clipping is a surge of energy equivalent to all the amps power? This happens because the amp is underpowered? Or why?

No, not really. It clips when the output of amplifier cannot provide the voltage required to preserve the waveform of the input voltage. When this happens, understandably the peak of the waveform would be capped at the maximum voltage the amplifier is capable of outputting. So if it is a sine wave, the top part of the original sine wave form will be "clipped" off, that is, with a flattened top part. In that sense it is really no longer a sine wave as such, but it is still made up of harmonics that are all sine waves including the fundamental and the harmonics of multiples of the fundamental frequencies.

https://en.wikipedia.org/wiki/Clipping_(audio)

A clipped periodic waveform can be represented by an infinite series containing the fundamental frequency and the harmonic frequencies. For example, when a 1 kHz sine wave signal clips, you will get in addition to the 1 kHz sine wave, a series of harmonics that may include 2, 3, 4, 5,........................nth harmonics so obviously the high pass filter of the crossover network will pass the higher order harmonic frequency signal to the tweeter. It does not mean any amplifier can kill any tweeter just because the signal is badly clipped. A 5 W amp is going to have hard time delivering the current needed to blow a 150 W "program power" rated tweeter through the crossover network, just an extreme example to make a point.

Edit: As @mtrycrafts pointed out, and thanks to him, there shouldn't be even order harmonics in the clipped sine wave I used as example. I won't edit it out because I stated it as "may include.., so it shouldn't mislead.., and in case the clipped sine wave may not be 100% symmetrical when real contents are played, and that means there would then be multiple sine waves and the waveform might in fact be not totally symmetrical, resulting in even order harmonics as well. Not trying to be argumentative, but it wouldn't hurt to be more inclusive.

 

[Out-Of-Phase]

So, in my case, I guess it could have been a combination of things, the receiver amplifier clipping and the design of the tweeter not being able to withstand the lack of current during peaks.

 

[snakeeyes]

No, not really. It clips when the output of amplifier cannot provide the voltage required to preserve the waveform of the input voltage. When this happens, understandably the peak of the waveform would be capped at the maximum voltage the amplifier is capable of outputting. So if it is a sine wave, the top part of the original sine wave form will be "clipped" off, that is, with a flattened top part. In that sense it is really no longer a sine wave as such, but it is still made up of harmonics that are all sine waves including the fundamental and the harmonics of multiples of the fundamental frequencies.

https://en.wikipedia.org/wiki/Clipping_(audio)

A clipped periodic waveform can be represented by an infinite series containing the fundamental frequency and the harmonic frequencies. For example, when a 1 kHz sine wave signal clips, you will get in addition to the 1 kHz sine wave, a series of harmonics that may include 2, 3, 4, 5,........................nth harmonics so obviously the high pass filter of the crossover network will pass the higher order harmonic frequency signal to the tweeter. It does not mean any amplifier can kill any tweeter just because the signal is badly clipped. A 5 W amp is going to have hard time delivering the current needed to blow a 150 W "program power" rated tweeter through the crossover network, just an extreme example to make a point.

So clipping can occur in lower watt amps more frequently but most speakers would not get damaged by a lower watt amp.

 

[PENG]

So clipping can occur in lower watt amps more frequently but most speakers would not get damaged by a lower watt amp.

It can occur even if you have a Monolith 200 W amp if you listen loud enough at a given distance. For example, if you listen to 2 channel classical music that has peaks of 20 dB and expect your amp to output an average of 10 W, depending on the music it would clip more often that you realize. For me, the average is more like between 0.2 to 25 W so I highly doubt my amps would clip on me.

I wouldn't say most speakers would be more frequently damaged by a lower watt amp because it depends on many other factors, including a few I mentioned in this and other threads.

 

[PENG]

and the design of the tweeter not being able to withstand the lack of current during peaks.

I am not sure what you meant. If the amp clipped during peaks, depending on how badly it clipped, and the contents you were playing at the time, it might have in fact generated enough harmonic contents for the crossover to pass on to the tweeter. In that case, that particular tweeter could have failed due to the heat generated by the excessive currents at the higher order harmonic frequencies. All else being equal, a different tweeter, a different amp, or a combination of both, might have resulted in a different outcome. As I mentioned before, imo it is better not to generalize.

 

[Out-Of-Phase]

I am not sure what you meant. If the amp clipped during peaks, depending on how badly it clipped, and the contents you were playing at the time, it might have in fact generated enough harmonic contents for the crossover to pass on to the tweeter. In that case, that particular tweeter could have failed due to the heat generated by the excessive currents at the higher order harmonic frequencies. All else being equal, a different tweeter, a different amp, or a combination of both, might have resulted in a different outcome. As I mentioned before, imo it is better not to generalize.

After the Kenwood, I had several receivers back in the day, JVC, Pioneer, Luxman, Yamaha and none of those blew any tweeters with any of my music. None.

I even tried to blow them up one day with my Yamaha and couldn't. After I ditched the Kenwood, something changed, something, but my speakers remained the same.

One thing I do remember with the Kenwood was the awful sound of the clipping right before losing a tweeter.

I remember later I went into the HiFi store where I bought my speakers and told them of my experience with the Kenwood. I got yelled at by an irate salesman who told me when I bought those speakers to not use that under-powered Kenwood or you will be sorry. Turns out, he was right.

So, I'll always wonder if it was the internal design of the Kenwood?
Would another brand and model of receiver with the same power ratings (30wpc rms) exert the same symptoms?

All I know is my future (more powerful) receivers were very kind to those speakers even at high volume.

 

[PENG]

After the Kenwood, I had several receivers back in the day, JVC, Pioneer, Luxman, Yamaha and none of those blew any tweeters with any of my music. None.

I even tried to blow them up one day with my Yamaha and couldn't. After I ditched the Kenwood, something changed, something, but my speakers remained the same.

One thing I do remember with the Kenwood was the awful sound of the clipping right before losing a tweeter.

I remember later I went into the HiFi store where I bought my speakers and told them of my experience with the Kenwood. I got yelled at by an irate salesman who told me when I bought those speakers to not use that under-powered Kenwood or you will be sorry. Turns out, he was right.

So, I'll always wonder if it was the internal design of the Kenwood?
Would another brand and model of receiver with the same power ratings (30wpc rms) exert the same symptoms?

All I know is my future (more powerful) receivers were very kind to those speakers even at high volume.

May be that particular Kenwood model would clip very badly as soon as it crossed a certain threshold, whereas your newer units would clip in more of a gently progressive way as output increases.

In fact if you look at the S&M and AH's bench test power vs THD graphs, you can see that some AVRs do have a more gentle slope after the knee point, whereas some just went straight up like almost 90 degrees.

Regardless, if as soon as the distortions became audible you turned the volume down you might have not have blown the tweeter, but you waited right? You said you even try to blow that the same tweeter with your Yamaha, sounded like you wanted an excuse to replace the speakers.

Before are just a few examples, not also NAD claimed to have a "soft clip" feature.

https://www.soundandvision.com/content/anthem-mrx-710-av-receiver-test-bench

 

[Out-Of-Phase]

So can we conclude it was the speakers or the receiver? Or perhaps both.

 

[Danzilla31]

So can we conclude it was the speakers or the receiver? Or perhaps both.

I vote both!

 

[mtrycrafts]

...
A clipped periodic waveform can be represented by an infinite series containing the fundamental frequency and the harmonic frequencies. For example, when a 1 kHz sine wave signal clips, you will get in addition to the 1 kHz sine wave, a series of harmonics that may include 2, 3, 4, 5,............................

Hyper Physics shows only odd harmonics:

Am I wrong on this?

 

[highfigh]

Are they saying just the distortion itself, regardless of the Power or Energy going to the drivers, is causing all the damage?
I assume they mean "a lot of distortion" in the form of "clipping" that causes more ENERGY (and high-frequency energy shift) to go to the drivers (especially tweeters).
But it makes sense to me that the excess ENERGY is what causes the damage.
If distortion occurs but the resulting energy is less than the limits of the drivers, how would this damage the drivers?
Wouldn't AVRs have built-in speaker protection circuits that would cause the AVR to go into Protection Mode if clipping occurs?
The Tone Controls point is interesting. I do know some people who love to use Tone Controls and Manual EQ to boost certain frequencies. If they were to boost the Treble frequencies, that could definitely push even more Energy toward the tweeter.

Distortion doesn't need to be in the form of clipped waveforms, IM distortion in high percentage creates sum & difference frequencies that can definitely cause damage to the drivers without much clipping. The energy from the distortion is added to the signal and that's where a speaker can meet its maker.

Using tone controls or any equalization takes knowledge and discipline if A) the results are to be positive and B) will leave the drivers and crossover unmolested.

 

[highfigh]

Honestly? I think it was both if you get down to it probably non accurate specs with the speakers and non accurate specs with the reciever. It's not like I was cranking it to reference or past. You never can tell with manufacturers these days. Best defense against that is my ears and eyes. That's what saved me there. It didn't sound right and it sure as hell didn't look right so what to do? Ya turn it down and never try that s$!#t with that particular gear again.

My biggest peeve is when manufacturers on speakers will say minimum 50 to 300 watts. Really? What exactly does this mean? I'd like a RMS precise measurement please. What can they really handle on a regular basis and still have room for dynamics swings and everything else? But you call them and they kind off dance around the question. It doesn't get better to some extent until you get to higher end audio. Sometimes.

I also hate that +- 3db. Really? Just spit it out fellas. Where can this baby really play too and where does it fall off at. If I like the speaker I'm gonna buy it anyways. I really don't care about the useless extension down to 38hz I can t hear that I'll be driving a sub for anyways. I get that you pretty much can measure where it falls off at by the +- measurement. But only if your learning like from here or from others. A lottof regular consumers just dont know what things like that mean. And that's how they get themselves in trouble

But it must work cause there making sells. Which I guess is why they fudge the numbers. Just the way things go I guess. I'm glad to be learning what I'm learning from here so I can learn to sift through and look for the info I really need.

How would you rate a speaker with your own chosen input signal if it's not musical and then try to explain to the end user that they killed their speakers with the signal from their favorite music?

Speakers are (usually) designed by engineers and for their purposes, the specs seen on data sheets for commercial/industrial models are totally different from what the marketing dorks trowel out for consumers. Why? Because the people who are considering commercial/industrial speakers understand what they're reading and looking at.

If consumers don't understand this stuff, whose fault is it? The info has been out there for decades. The problem- too many people don't understand scientific principles and the high school math that goes with them, often having said "I don't know why I have to learn this, I'll never use it after I graduate". Classic case of Never say "never".

Be mad at the marketing departments, not the engineers who know what's going on and can communicate in terms that mean something.

 

[Danzilla31]

How would you rate a speaker with your own chosen input signal if it's not musical and then try to explain to the end user that they killed their speakers with the signal from their favorite music?

Speakers are (usually) designed by engineers and for their purposes, the specs seen on data sheets for commercial/industrial models are totally different from what the marketing dorks trowel out for consumers. Why? Because the people who are considering commercial/industrial speakers understand what they're reading and looking at.

If consumers don't understand this stuff, whose fault is it? The info has been out there for decades. The problem- too many people don't understand scientific principles and the high school math that goes with them, often having said "I don't know why I have to learn this, I'll never use it after I graduate". Classic case of Never say "never".

Be mad at the marketing departments, not the engineers who know what's going on and can communicate in terms that mean something.

I don't know where this turned into I'm blasting engineers. Never said that I just stated the things about accuracy that I disliked when I first got into this that I had to learn the hard way to work around.

As for the marketing I work in psych nursing. And that's where my naivety and eyes were opened up. Big Pharma was sued an astronomical sum for fudging the numbers and results some they even hid of serious side effects of Zyprexa. It's not just audio that pulls this practice. It's everywhere. It's in human nature to fudge or pitch something to get them the success they want out of it. If they will do it with medicines that can have a permanent impact on your life. They'll Damn well do it with audio

I've learned to accept that about life. But I don't have to like it.

I'm kind off for the ignorant consumer on this one. Because I've been one. Math and science were a struggle on me. But poetry and philosophy I could ace without even trying. Probably why I can talk a 280 lb psychotic to calm down in the quiet room without him getting physical and putting 4 dudes in the hospital and Joe Blow over there can design a speaker that can sing to the angels. Something I never could do

Learning on these sites and doing research can be a pain in the a@$! Because of the sometimes condescending elitist smug attitude of the ones with the knowledge that we are humbling ourselves to learn it from. Don't fudge specs then tell me I should have been paying more attention in school. I was paying attention and so were a lot of other people. But either our minds aren't gifted in that way or you got a soccer mom with 3 kids who really wants to get something that sounds nice but doesn't have the time to be up on audioholics all night long.

Could these companies A either take there honest money and provide them with better information. Or B could some of the people with the knowledge be a little compassionate and dumb it down for the person rather then rubbing it in there face what they should know when they finally do reach out on these sites? So many members on these forums are so awesome and helpful. But you always gotta get the ones that try to think they can talk to you like your 5 years old.

Its that narrow minded attitude that hurts people from wanting to learn more about this awesome hobby in the long run. Who wants to learn when they gotta get there face rubbed in it?

Once again it's just life I gotta accept it but don't expect me to like it. Thats how I feel about it any way

 

[Reckel]

I don't know where this turned into I'm blasting engineers. Never said that I just stated the things about accuracy that I disliked when I first got into this that I had to learn the hard way to work around.

As for the marketing I work in psych nursing. And that's where my naivety and eyes were opened up. Big Pharma was sued an astronomical sum for fudging the numbers and results some they even hid of serious side effects of Zyprexa. It's not just audio that pulls this practice. It's everywhere. It's in human nature to fudge or pitch something to get them the success they want out of it. If they will do it with medicines that can have a permanent impact on your life. They'll Damn well do it with audio

I've learned to accept that about life. But I don't have to like it.

I'm kind off for the ignorant consumer on this one. Because I've been one. Math and science were a struggle on me. But poetry and philosophy I could ace without even trying. Probably why I can talk a 280 lb psychotic to calm down in the quiet room without him getting physical and putting 4 dudes in the hospital and Joe Blow over there can design a speaker that can sing to the angels. Something I never could do

Learning on these sites and doing research can be a pain in the a@$! Because of the sometimes condescending elitist smug attitude of the ones with the knowledge that we are humbling ourselves to learn it from. Don't fudge specs then tell me I should have been paying more attention in school. I was paying attention and so were a lot of other people. But either our minds aren't gifted in that way or you got a soccer mom with 3 kids who really wants to get something that sounds nice but doesn't have the time to be up on audioholics all night long.

Could these companies A either take there honest money and provide them with better information. Or B could some of the people with the knowledge be a little compassionate and dumb it down for the person rather then rubbing it in there face what they should know when they finally do reach out on these sites? So many members on these forums are so awesome and helpful. But you always gotta get the ones that try to think they can talk to you like your 5 years old.

Its that narrow minded attitude that hurts people from wanting to learn more about this awesome hobby in the long run. Who wants to learn when they gotta get there face rubbed in it?

Once again it's just life I gotta accept it but don't expect me to like it. Thats how I feel about it any way

Hey buddy I absolutely agree with you! I’m in a different profession than but trust me when I say that I see things every night that would disgust the majority of people and society has no idea what is really going on out in the world. They want to just believe the media, well I’ve got news for those, the media is full of bs and they don’t report the truth

 

[PENG]

Hyper Physics shows only odd harmonics:
View attachment 26588
Am I wrong on this?

Of course Hyper Physics was right! The only caveat is that what you quoted has to do with clipped wave that are symmetrical. In practice, I would assume in severe case of clipping, the waveform would likely be asymmetrical, at least slightly, so I don't see the need to exclude even order harmonics though their magnitude would be much lower perhaps to the point of being insignificant. I have recently started the process of gradually sorting and sending my university text books and notes to garbage, now I feel like keeping anything that has to do with audio and Fourier.

 

[Danzilla31]

Hey buddy I absolutely agree with you! I’m in a different profession than but trust me when I say that I see things every night that would disgust the majority of people and society has no idea what is really going on out in the world. They want to just believe the media, well I’ve got news for those, the media is full of bs and they don’t report the truth

Yeah I see a lot of tough stuff in my profession as well. Keep doing what your doing brother. Appreciate your commitment in your field. I'll try to keep up the fight from my end. All we can do is what we can do. Thanks for the kind words I've seen you on here before enjoy your posts looking 4ward to continuing to get to know ya with this hobby we got here