Now Iblew the tweeter in the other R50?

madmax · February 2005

Tour has finally lost it.

La la la la la la la la la la la land....

madmax

F1nut · February 2005

Originally posted by madmax
Tour has finally lost it.

La la la la la la la la la la la land....

Yeah, what he said!

Tour2ma · February 2005

Originally posted by madmax
Tour has finally lost it.

La la la la la la la la la la la land....

madmax

No wonder I started agreeing with you...

MacLeod · February 2005

I feel so alone!

You're talkin' subs, and saying speakers and meaning subs

Im saying speakers and meaning ANY speaker. I just keep using subs cause how many 1500 watt tweets you seen around? LOL A tweeter capable of handling 200 watts wont be hurt by an amp clipping at 100 watts.

Been saying all along... Clipping kills tweeters ...Far more prevelant than overpowering them.

When an amp clips, it puts out about double its power rating. This is what kills the speaker. If the clipped signal is under the speakers power handling, the speaker wont be hurt.

my friend who kept frying tweeters was clipping his receiver now that i think of it. it would some times shut itself down. just recently he added a 2 ch. amp and he hasn't had that clipping problem anymore.

Right because he doesnt have to turn it up as much to get to the volume level he wants. But, rest assured, if that amp puts out more power than the speakers can handle, it will fry those tweeters jsut as quickly as the crappy amp did because when the crappy amp clipped, it doubled the power and pushed the tweeters beyond their limits.

Far more tweeters are toasted due to not enough power, than by too much---due to people pushing their under-powered amp too far, causing clipping.

Go install a set of 150 watt Polk MM6 components in your car and power them with the cheapest, crappy 10 watt per channel head unit you can find. Turn it all the way up to max and youll never fry those speakers. Why? Cause even in clipping, that head unit wont put out any more than 25 watts or so which is about 125 below the limits of the MM6.

Now, if this has changed for some reason in the last 40 years, I'd like to read about it...

Well, here is some good reading by Richard Clark, one of the most renowned engineering gurus in car audio.

Cody, Joel! You guys get your asses in here!

F1nut · February 2005

Originally posted by MacLeod
I'm saying speakers and meaning ANY speaker. I just keep using subs cause how many 1500 watt tweets you seen around? LOL A tweeter capable of handling 200 watts wont be hurt by an amp clipping at 100 watts.

I've killed a few tweeters and have known others that have too. It was always done with underpowered amps. I've never cooked one with high quality, high powered amps, never. What happens to a tweeter when it's underpowered vs overpowered is very different. When underpowered and clipping (distortion) occurs the voice coil cooks, when feed too much power a tweeter will basically explode, sometimes in flames.

When an amp clips, it puts out about double its power rating. This is what kills the speaker. If the clipped signal is under the speakers power handling, the speaker wont be hurt.

Clipping is distortion and distortion is what damages a speaker.

Tour2ma · February 2005

High frequency...

There is another consequence of operating an amplifier into clipping: high frequency harmonics will be generated. Any time a signal is clipped, the waveform's spectrum (frequency components) will be altered. The result is that more high frequency energy is generated (as compared to what was present in the signal to begin with). The crossover in the speaker system will direct the higher frequency energy to the midrange and tweeter speakers, and these (especially tweeters) will be more susceptible to burnout.

The risk of damage to the speakers depends on the characteristic of the music (does it have lots of high frequency energy to begin with?), to what degree of clipping is occurring and how conservatively the speakers are rated. It is not uncommon to blow tweeters when operating an amp into clipping.

With average music material (and typical crossover frequencies for a 3-way speaker), about 70 percent of the amplifier's output energy is directed to the woofer, maybe 20-25 percent to the midrange, and 5 or 10 percent to the tweeter. If clipping occurs, the power to all speaker components increases, however the ratios given above change (such that the midrange and tweeter end up trying to deal with more than their share of the power). As should be fairly obvious, this can lead to premature failure of the midrange and/or tweeter.

From a pretty fair write-up... http://www.rocketroberts.com/techart/powerart_a.htm

The author does discuss the increase in amp power at clipping, but it is RMS power that rises owed to the amplifier compressing the music signal through.... taadaa... clipping...

Tour2ma · February 2005

Oh, and I read the pdf partly by Mr. Clark, partly by David Narvone (another guru?)... Clark says "subs" about three time in the first two paragraphs, but I hung in there...

Narvone does mention "extra 3 dB of energy... 1 dB is higher frequency" (quote approximated due to inability to cut and paste from pdf's), but blows it off by implying it is not meaningful to come movement... Gonna guess he's referring to a sub here...

And there's plenty of square wave talk... Can't fathom the belief that it is less stressful on any driver than a good old sine wave...

Anyway... I think we can all agree on two things:
- clipping is not good.
- heat damages voice coils...

Any increase in current to a voice coil increases the amount of heat it will have to dissapate.
Power, high freqency material and distortion all increase current flow...

What we disagree on is what is the most significant source if undesired current...

And don't think I failed to notice how you ignored the Mach 1 analysis I did...

Now go sit in your car...

steveinaz · February 2005

The article you posted is addressing subs---again. Subs can take enormous amounts "raw" power and survive. Tweeters cannot. In fact you'd be amazed how much power a table radio speaker can take before failure, even though most of those are rated in "tenths of a watt."

The issue here is tweeters and amplifier clipping. True, amps do produce wattage far beyond their rated output beyond the on-set of clipping---the kind of power you light light bulbs with; but it's the overload of ultrasonics that fry the tweeter--ultrasonics induced by clipping.

PolkThug · February 2005

Yeah, but will Brett Selinsky blow a third tweeter?:p

madmax · February 2005

Originally posted by MacLeod

When an amp clips, it puts out about double its power rating. This is what kills the speaker.

I really don't know where you got this rule of thumb but it is wrong. When the amplifier clips it produces a square wave output which can be many times the specified power. Another thing to keep in mind is that speaker manufacturers have a lot of data to consider before putting a power limit spec on a speaker. How they do it can be varied.

madmax

PolkThug · February 2005

Richard Clark kicks butt, he put a lot of people/manufacturers in their place with the amp challenge.

steveinaz · February 2005

OK, do this:

Take a 35 watt receiver (any brand) connect it to a tweeter. Gradually turn up the receiver until the tweeter dies. Using an SPL meter measure how loud the tweeter played.

Take a 200 watt power amp, do the same. I'll bet you my next months paycheck that the tweeter will play far louder before giving out on the higher wattage amp.

It isn't clean power that kills tweeters, it's clipped signals. Though you can blow a tweeter with brute force watts, no doubt--but clipping will blow it long before brute force power comes into play.

Tour2ma · February 2005

steve,
Even I'd have to take that bet with no x-over in play...

Especially since I no longer get a monthly paycheck...

Tide · February 2005

Originally posted by PolkThug
Yeah, but will Brett Selinsky blow a third tweeter?:p

Does Vegas have a line on this yet? Who wants to guess the over/under on number of days until the next blown tweeter?

Tour2ma · February 2005

Over/ Under??? We can e-mail PTI and get their take...

TheReaper · February 2005

Originally posted by steveinaz
OK, do this:

Take a 35 watt receiver (any brand) connect it to a tweeter. Gradually turn up the receiver until the tweeter dies. Using an SPL meter measure how loud the tweeter played.

Take a 200 watt power amp, do the same. I'll bet you my next months paycheck that the tweeter will play far louder before giving out on the higher wattage amp.

The psychoacoustic theory of how clipping blows tweeters:

What happens is, once you start clipping, the amplifier can no longer amplify the loud part of the sound (the part that is being clipped). The amplifier can only amplify the softer part of the sound (the part that is not being clipped). In order to perceive the sound as being louder, the amplification of the softer part of the sound is greater, then amplifying both the loud part and soft part together (as would happen with a more powerful amp that is not clipping). The net result is, you are adding more and more power (continous power), to get less and less of a perceived volume increase, once an amp is clipping.

MacLeod · February 2005

Clipping is distortion and distortion is what damages a speaker.

Clipping is distortion but distortion in and of itself doesnt hurt a speaker. If you have a 100 watt signal distorted all to hell playing into a 200 watt tweeter, itll never blow.

And there's plenty of square wave talk... Can't fathom the belief that it is less stressful on any driver than a good old sine wave...

The shape of the wave isnt the problem. If it is within the tolerance of the speaker it wont bother it. I.E. A 100 watt distorted, clipped signal into a 200 watt tweeter. Nothing happens other than it sounds like ****.

The article you posted is addressing subs---again.

No, its addressing speakers. Subs are speakers and work just like tweeters and midranges.

but it's the overload of ultrasonics that fry the tweeter--ultrasonics induced by clipping.

No, its the overload of power. Ill go back to my MM6 analogy. I can hook up my Alpine 15x4 head unit to my 150 watt MM6, turn the volume all the way to max and play it like that for years and never hurt those speakers.

I really don't know where you got this rule of thumb but it is wrong. When the amplifier clips it produces a square wave output which can be many times the specified power.

Umm...isnt that what I said?

Take a 35 watt receiver (any brand) connect it to a tweeter. Gradually turn up the receiver until the tweeter dies. Using an SPL meter measure how loud the tweeter played. Take a 200 watt power amp, do the same. I'll bet you my next months paycheck that the tweeter will play far louder before giving out on the higher wattage amp.

It isn't clean power that kills tweeters, it's clipped signals. Though you can blow a tweeter with brute force watts, no doubt--but clipping will blow it long before brute force power comes into play.

Ill take a 35 watt receiver and play it thru a 200 watt speaker (tweeter, mid, sub whatever) and itll never blow. But assume I hook it to a tweeter that dies at 50 watts. I turn up the 35 watt receiver until it clips. When it clips the power jumps to about 80 watts thus frying the 50 watt tweeter. Now take the 200 watt receiver and turn it up. Once it goes beyond 50 watts the tweeter dies. The reason it sounded louder was that a distorted signal isnt as loud as a clean signal but the speaker doesnt know the difference. All it knows is its getting 50 watts and once it goes beyond that 50 it dies, regardless if its clean or distorted.

The reason the "underpowering kills" theory got started is that most people dont power 500 watt speakers with 50 watt amps. If they did tho, it would never blow those speakers. Most people consider underpowering to be more like powering a 100 watt speaker with a 60 watt amp. This would kill the speaker cause youre more likely to clip the amp at which point the power jumps to about 130 watts and squish! It wasnt the clipping or the distortion. It was the 130 watts which was caused by the clipping.

Is anyone keeping score? I think Im losing.

Tour2ma · February 2005

It's not a matter of winning or losing... it's a matter of convincing... and in case you have not caught on, you are not convincing me/ us...

I can hook up my Alpine 15x4 head unit to my 150 watt MM6, turn the volume all the way to max and play it like that for years and never hurt those speakers.

You say "can". Have you actually done this? Not for years, but how 'bout an hour?

Part of the issue is your solution to clipping, i.e., grossly underpowering speakers, is practical only in the car audio world. Why? Because car cabin volumes (as in cu ft, not dB) are many times smaller than the smallest of man cave, home listening rooms. In cars, tiny amps can drive speakers to unbearably high SPL's. In homes you need more power.

So if the level of power you have leads to clipping, and you are unwilling to reduce listening levels, the only solution is to increase amplifier power.

MacLeod · February 2005

It's not a matter of winning or losing... it's a matter of convincing... and in case you have not caught on, you are not convincing me/ us

In case you didnt catch on, it was a joke.

You say "can". Have you actually done this? Not for years, but how 'bout an hour?

Ive done it several times over the last several years and for extended periods. I used to drive around with a pair of MTX Road Thunder boxs (2 subs, 2 mids, 2 tweets) powered by a Sony 25x2 "power booster" :rolleyes:. I would drive around for hours with it cranked to the max. It was loud (screechy) as hell. Sounded like **** too. It was clipped and distorted as hell but those boxes never so much as whimpered. Why? Cause they could handle well over 200 watts and even tho that Sony was putting out one hell of a clipped and distorted signal, it never got anywhere near the limits of those speakers.

Part of the issue is your solution to clipping, i.e., grossly underpowering speakers

Oh come on! Do you really think Im advocating powering 150 watt speakers with 15 watts? Give me a little credit. I would never do that nor would I recommend doing that. Im just using it as an illustration of my point.

The only thing that kills a speaker is getting hit with too much power and either building up more heat than it can dissipate or being forced to move beyond the limits of its suspension. It doesnt matter if that signal is clean, distorted or clipped. If it is below the limits of the speaker, the speaker will be fine. If it is beyond the limits, then the speaker dies.

How 'bout we go out on common ground here:

A - A clipped signal is much more likely to kill a speaker than a clean one.

B - You should always power your speakers properly.

C - Too much power kills speakers.

:cool:

F1nut · February 2005

There's one big problem with a lot of this post. People are not talking about the same thing. The problem is with tweeters, not entire speakers, not subs, just tweeters!

As such, it is a well known fact in the audio world that you will cook a tweeter easier and faster when cranking up the volume with a low powered amp rather than a high powered amp because the low powered amp clips easier and sooner. That is a indisputable fact.

Tour2ma · February 2005

Jesse,
Still agree that grossly overpowered amp capability is the safest ground... at least where no small children, or (worse yet) teenagers or (worse yet) guys from NJ named Tony are around...

All,
I'm done arguing. Not because I am tired of it, or defeated, or because I can't convince anyone I'm right... OK, maybe a little due to this last point..

... but mostly because I'm going for a deeper understanding. (Yup, Jesse, the Engineer is coming out...

)

I did a bunch of searching and reading today. Some of the sites I found have some pretty good science behind them; some had none at all. And while no one site provided a definitive treatment of the subject, cummulatively I think I came away with a better, more holistic take on the topic, but no firm conclusions yet. Now I am just trying to understand....

Mac,
Truce for now... but let's hold off on the common ground and just agree to holster our guns for now... Mmmm-kay?

Yup, I knew you were joking about the losing. But the "convincing" comment I made was meant. We're all just going round and round now, restating what we'd already covered. It's why I asked if you'd performed the clipping test (me, testing your convictions... you passed

) and went off in search of "the truth"... but alas no Holy Grail of Clipping web-sites to be found...

Also trying to raise new discussion points is why I raised the question around your "low power" solution and followed it (in case you did not notice) with observations on the car audio world vs. the home audio world... just some new material, not meant to demean, but to stimulate and clarify.

Couple questions on your car test...
You said your speakers were 200 watt rated. This is an overall rating I'm sure, so do you know what your tweeters' rating was? Are they more in the 10 to 20 watt range?
For the Sony 25x2... was 25 watts the max or continuous rating?

More later...

EDIT: Almost forgot... we could just forget the whole thing and go with the POLK FAQ explanation...
http://www.polkaudio.com/home/faqad/q.php?article=whybreak

MacLeod · February 2005

As such, it is a well known fact in the audio world that you will cook a tweeter easier and faster when cranking up the volume with a low powered amp rather than a high powered amp because the low powered amp clips easier and sooner. That is a indisputable fact.

I agree totally with this bro. With underpowering a speaker (say 50 watt amp to a 100 watt speaker) you will need to turn it up more to get the sound youre after. With the smaller amp youre more likely to turn it to the point of clipping at which point the amp makes around 120 watts thus killing the 100 watt speaker.

I think we're all in agreement about 99%. Where I differ is that I claim its the overpowering coming from the clipping , regardless of distortion, that is destroying the speaker and you guys claim its the square wave or distortion, regardless of the power, that is the culprit.

Couple questions on your car test...You said your speakers were 200 watt rated. This is an overall rating I'm sure, so do you know what your tweeters' rating was? Are they more in the 10 to 20 watt range?
For the Sony 25x2... was 25 watts the max or continuous rating?

LOL! I wouldnt exactly call that a test partner. More like me thinking Im the man cause my **** was loud. Didnt matter that it sounded like ****! The Sony "power booster :rolleyes: " was 25x2 RMS. Youre right that the rating for the MTX's was 200 RMS per box (1 sub, 1 mid and 1 tweet) and so I would agree with you that the tweet was about 10-20 watts. My point was tho that even tho they were getting a horribly clipped and distorted signal, it was well below their power handling and so didnt hurt it. There again my point being that distortion doesnt hurt speakers if its below their power handling.

All in all, I think we have argued this to death and as such should put it to rest. I dont want to start any bad blood. Ive always enjoyed a good intellectual exchange such as this and since none of my cowardly car audio homies see fit to come to my aid I think its time we move on to other things!

F1nut · February 2005

Speaking for at least Tour (I can speak for him since he played MJ on my big rig....ugh!!!) and I, no bad blood at all.

Carry on.

Tour2ma · February 2005

There you go Mac... see how forgiving Jesse can be... Hee-hee

No bad blood here either... but my blood is up and my thirst for knowledge must be quenched... :cool:

"I'll be back..." - Tour2ma-nator

MacLeod · February 2005

Bring it on!

Now Iblew the tweeter in the other R50?

Comments