For the last time, PLEASE: clipping does NOT blow speakers/subwoofers

[thch 10+ year member]

Is that MSEE for masters in EE, or materials electrical engineering?

M Sci, Electrical Engineering.

there is also a lot of background material on cases that make clipping more dangerous to speakers or woofers. Speakers can be damaged from clipping due to distortion, which tends to increase power in higher frequencies. this places more stress on the smaller drivers. such drivers may be rated for musical power, and may not be able to handle the additional actual power.

for woofers, some more exotic boxes, like the ABC box (box ported into another box that has a port to the outside world.) can generate exceptionally unfavorable thermal conditions for the woofer, and are known for damaging speakers at levels well within manufacturer's specs.

the latter is not so much an issue of clipping.

I have always been a proponent of using the DMM for informational purposes. making the decision firstly with a subjective "this sounds good" manner and then looking at the "is this safe/can I live with the risk" question with the DMM.

for fun though, any EE student should try to:

1.) explain why literal "RMS" power is useful spec. (its not, but the listed "RMS" power isn't actually the RMS value of power...)

2.) determine the THD% of a fully clipped sine wave.

3.) determine the difference in power between a sine wave and square wave)

4.) show that, for a highpass filter, as frequency decreases the peak voltage output increases for square waves. (the RMS voltage decreases).

each of these can be applied to the topic.

 

[PV Audio 5,000+ posts]

Let's not get all technical.

Many of the previous analogies are correct, like the one about jumping off of a skyscraper - that's not what kills you, the impact does.

For the common audio guy clipping does blow speakers/subwoofers. If you lead him to believe otherwise, much clipping will ensue thus blowing many speakers/subwoofers. Then he will come on here calling us all liars because he blew all of his subs from clipping.

If the amp puts out anywhere near the RMS (not rated, but actual) of the subwoofer, clipping will eventually blow the woofer, simple as that.

No, this is a crock of bullshit. I have never not once EVER owned a car audio system outside of speakers and headunit; no subwoofers have ever been in my car. However, I have owned and tested more drivers and amplifiers and have set up and tested more systems than I can count because of a simple fact: audio is audio, where the components are is irrelevant. You can clip, no, you WILL clip a home audio receiver by playing a movie. Unless you're spending thousands on the best of the best receiver, you will always have some amount of clipping as a receiver's internal amplifier is not sufficient to drive most speakers to the output you want.
This knowledge is completely analogous to a car audio subwoofer. You can't say that the common audio guy's subs blow because of clipping, and the experienced audio guys subs don't. That's logically impossible, and you know it. Perpetuating falsities is not the way to further your argument, and the fact that somehow people are better off by being taught incorrect knowledge is equally ridiculous.

 

[PV Audio 5,000+ posts]

M Sci, Electrical Engineering.

there is also a lot of background material on cases that make clipping more dangerous to speakers or woofers. Speakers can be damaged from clipping due to distortion, which tends to increase power in higher frequencies. this places more stress on the smaller drivers. such drivers may be rated for musical power, and may not be able to handle the additional actual power.

for woofers, some more exotic boxes, like the ABC box (box ported into another box that has a port to the outside world.) can generate exceptionally unfavorable thermal conditions for the woofer, and are known for damaging speakers at levels well within manufacturer's specs.

the latter is not so much an issue of clipping.

I have always been a proponent of using the DMM for informational purposes. making the decision firstly with a subjective "this sounds good" manner and then looking at the "is this safe/can I live with the risk" question with the DMM.

for fun though, any EE student should try to:

1.) explain why literal "RMS" power is useful spec. (its not, but the listed "RMS" power isn't actually the RMS value of power...)

2.) determine the THD% of a fully clipped sine wave.

3.) determine the difference in power between a sine wave and square wave)

4.) show that, for a highpass filter, as frequency decreases the peak voltage output increases for square waves. (the RMS voltage decreases).

each of these can be applied to the topic.

I'm not as advanced as the other EEs here, I'm only 2nd year undergrad //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[PV Audio 5,000+ posts]

PLEASE GO OVER TO THE MECA FORUMS AND EXPLAIN THIS. I argued about this topic for about 6 pages and nobody agreed with me.

I doubt that if they won't listen to one engineering student that they'll listen to two. It is obvious how they're thinking, but the problem is this: if you climb up to the top of a building and stand on the edge, you could jump off and die, have the wind blow you over the edge and die, have a bird hit you in the face and push you off and die, have a meteorite hit you and kill you, etc. Saying that any one of these caused your death is fairly true. However, saying that flying birds and wind causes people to die is what people are saying when they say clipping kills speakers. There are so many ways to get to the end point of blowing a speaker that you simply cannot state that one of those ways will do it. It's a situational occurrence at best, because a low flying bird will rarely knock a person off the side of a building, just as a tube amplifier clipping will rarely blow a speaker.

 

[maldecido33 10+ year member]

M Sci, Electrical Engineering.

there is also a lot of background material on cases that make clipping more dangerous to speakers or woofers. Speakers can be damaged from clipping due to distortion, which tends to increase power in higher frequencies. this places more stress on the smaller drivers. such drivers may be rated for musical power, and may not be able to handle the additional actual power.

for woofers, some more exotic boxes, like the ABC box (box ported into another box that has a port to the outside world.) can generate exceptionally unfavorable thermal conditions for the woofer, and are known for damaging speakers at levels well within manufacturer's specs.

the latter is not so much an issue of clipping.

I have always been a proponent of using the DMM for informational purposes. making the decision firstly with a subjective "this sounds good" manner and then looking at the "is this safe/can I live with the risk" question with the DMM.

for fun though, any EE student should try to:

1.) explain why literal "RMS" power is useful spec. (its not, but the listed "RMS" power isn't actually the RMS value of power...)

2.) determine the THD% of a fully clipped sine wave.

3.) determine the difference in power between a sine wave and square wave)

4.) show that, for a highpass filter, as frequency decreases the peak voltage output increases for square waves. (the RMS voltage decreases).

each of these can be applied to the topic.

I'll do a writeup answering those questions at some point in the next couple of days, but I just wanted to post to LOL at the first quote in your sig.

 

[mil81 10+ year member]

There are only two ways to blow a driver: mechanical failure or thermal failure. The former is due to over excursion of some form from some cause (usually improper enclosure), and the latter is usually from overpowering the speaker. If you feed a Type-R a fully clipped signal from a 300 watt amp, it will not reach thermal failure in the least. It might sound like shit, but it won't cause the speaker to fail. The driver doesn't know what it's being sent, all it does is get fed power and turn that into sound. Whether or not the signal is distorted is irrelevant.

I didn't finish the last bit of this thread, so I hope I'm not being redundant.

As you stated, mechanical failure kills speakers. That means when the speaker gets pushed past it's limit of movement. The clipped section of a sine wave IS a DC signal. What happens when you send a DC signal to a speaker? Does it not push it out to it's maximum limit, and then some? So would this "DC" signal generated by a clipped sound wave not damage the speaker as well?

On top of that, you stated that thermal failure can cause damage to a speaker. What happens when you send straight DC to a coil? It overheats, and the coating melts. Don't you think this would slowly happen with a clipped sine wave as well.

If I am incorrect, please give proof. I am open to different theories.

Murray

 

[Lakota 5,000+ posts]

I didn't finish the last bit of this thread, so I hope I'm not being redundant.
As you stated, mechanical failure kills speakers. That means when the speaker gets pushed past it's limit of movement. The clipped section of a sine wave IS a DC signal. What happens when you send a DC signal to a speaker? Does it not push it out to it's maximum limit, and then some? So would this "DC" signal generated by a clipped sound wave not damage the speaker as well?

On top of that, you stated that thermal failure can cause damage to a speaker. What happens when you send straight DC to a coil? It overheats, and the coating melts. Don't you think this would slowly happen with a clipped sine wave as well.

If I am incorrect, please give proof. I am open to different theories.

Murray

The current is not technically DC when the top of a sinusoidal wave is clipped off, it just has a slope of 0 for that period. The wave is still alternating between positive and negative, thus still being AC. The change is in the waveform itself, not its direction.

When you send DC to a sub the sub will just move into the direction of the applied voltage, i.e. up if wired in phase and down if wired 180 degrees out of phase. The sub will not move both up and down because the current isn't alternating between positive and negative (has no frequency).

Here's some proof from Rockford Fosgate themselves. It is explained in the last paragraph. http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/std_adp.php?p_sid=FQNNCi4j&p_lva=&p_faqid=63&p_created=965346111&p_sp=cF9zcmNoPTEmcF9ncmlkc29ydD0mcF9yb3dfY250PTkmcF9zZWFyY2hfdGV4dD1kaXN0b3J0aW9uJnBfc2VhcmNoX3R5cGU9MyZwX3Byb2RfbHZsMT1_YW55fiZwX3Byb2RfbHZsMj1_YW55fiZwX2NhdF9sdmwxPX5hbnl_JnBfY2F0X2x2bDI9fmFueX4mcF9zb3J0X2J5PWRmbHQmcF9wYWdlPTE*&p_li=

 

[psych0ticnemes1 5,000+ posts]

Nice article. In other words, clipping will cause a coil to heat up faster than a clean signal... right?

 

[audioholic 5,000+ posts]

Additionally, simply sending a speaker DC would not ensure it excurts to its maximum in one direction. It takes a certain amount of energy to push a speaker's suspension, this DC current would need enough amperage in it to produce the power necessary to push the speaker to its mechanical limits.

DC would just mean it would push it in one direction only, not that it would push it to its limits in that direction.

 

[btdickey99 5,000+ posts]

Nice article. In other words, clipping will cause a coil to heat up faster than a clean signal... right?

yes bc it sends more powa in a sense

 

[Lakota 5,000+ posts]

Nice article. In other words, clipping will cause a coil to heat up faster than a clean signal... right?

Once a signal is clipped there is more area under the curve, thus the signal is carrying more energy. More energy = more power = more heat. This doesn't mean that square wave itself is worse for a speaker, but the energy that it carries is what matters.

 

[maldecido33 10+ year member]

Nice article. In other words, clipping will cause a coil to heat up faster than a clean signal... right?

Yes, because it will transfer more power than a clean signal. Power + friction = HEAT. The heat will cause the sub to reach it's thermal limits.

 

[audioholic 5,000+ posts]

When discussing 'more area under the curve' in a waveform, the key is to realize that this displays more power over time.

 

[Lakota 5,000+ posts]

If you'd like a good article that is much more in depth, here is one that Richard Clark wrote. http://www.monstercable.com/mpc/stable/tech/A2420_Some_Facts.pdf

Here's the part that's important to this thread:

"The

total energy represented by both tracks is exactly the same and will produce virtually the same heating

effect in the voice coil of a speaker. The speaker doesn't care if the music is distorted or not. To a

speaker it is all just a combination of sine waves. A speaker cannot tell the difference between noise,

distortion, or music. It doesn't care what kind of music it is or any thing else about it except how much

energy is contained in the signal."

 

[Lakota 5,000+ posts]

I should also mention that if distortion was so bad for speakers then everybody that listens to Soulja Boy would instantly fry their speakers //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif