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I Grossly Underpowered my Speakers . . .

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restorer-john said:
I spent a long time doing autopsies of dead speakers to determine whether they were factory flaw warranty claims or just drunk idiots turning the volume up for too long.
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I'm not doubting you, and I too have determined whether a speaker failed, or was blown. But how do determine HOW it was blown? I would imagine that high-frequency energy and just high power will both result in burnt/boiled voice coils. Energy is energy regardless of frequency. Just asking.
 
Artie said:
I'm not doubting you, and I too have determined whether a speaker failed, or was blown. But how do determine HOW it was blown? I would imagine that high-frequency energy and just high power will both result in burnt/boiled voice coils. Energy is energy regardless of frequency. Just asking.
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Cooked voice coil- long term over powering. (ie too much bourbon)

Vaporised lead in wire to VC but VC otherwise fine- transient event, check amplifier stability.

The voice coil has thermal inertia. It can take peaks and dissipate the heat. The lead-in wire cannot. It goes up like a fuse.

(this is in relation to tweeters only)
 
restorer-john said:
Cooked voice coil- long term over powering. (ie too much bourbon)

Vaporised lead in wire to VC but VC otherwise fine- transient event, check amplifier stability.

The voice coil has thermal inertia. It can take peaks and dissipate the heat. The lead-in wire cannot. It goes up like a fuse.

(this is in relation to tweeters only)
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Cool. Good info. I learned something new.
 
restorer-john said:
Well done? Not at all.

Although this thread has good intentions, it's also full to the brim with mis-information, basic errors and a complete lack of understanding of the methods and modes of driver failure in the face of excessive transient events.

I can destroy the so-called 250W RMS loud-speaker tweeters with a transient event from a 20 watt amplifier, day in, day out. Anyone who thinks otherwise, is living in dreamland.

People tend to forget that an amplifier that clips, doesn't just clip. It often becomes unstable. It becomes an open loop, high powered oscillator. The NFB loop essentially lets go. Yes, a full rail-to-rail oscillator at whatever frequency it settles at- usually ultrasonic. You know, the stuff you can't hear?

And guess what? That amplifier can deliver its FULL RATED POWER into that pissant tweeter at HF. Result? Instantly. Dead. Tweeter.

Not rocket science. Normal music doesn't present significant content at HF frequencies and levels, nor does it generally stimulated oscillations. Instability/oscillation unfortunately does.

I spent a long time doing autopsies of dead speakers to determine whether they were factory flaw warranty claims or just drunk idiots turning the volume up for too long.
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Yeah I also never understand these arguments for underpowered amps pose no threats.

Big reason being, I DID IT.

As a young kid in the 80s my folks were far too tolerant of my love of gear and music. And my dad was my partner in crime. I had a Technics 35 watt silver face receiver and a (super cool to me then) realistic brand eq with the spectral display which I naturally made smile faces on the channel. Because as we all know that's what sounds best lol.

I cant tell you how many times I blew tweeters on various speakers rated for 100-200 watts. At the time, not knowing how terribly I setup the system and was bleeding a turnip with the over burdened underpowered receiver.

My god I couldnt have made a more perfect storm driving 2 pairs of speakers on a 35 watt receiver with a smiley face eq mixed in. I might as well plugged it all into an electric chair and at least made the death quick and painless lol.

But I was kid and I nor my father knew any better so we just kept buying replacement tweeters and or different speakers.

The thing that hurts most looking back on that time was one of my victims. My father being the loving and generous guy he was towards me gave me his infinity monitor jr speakers to help give me that kick ass stereo. They didnt deserve that fate. Again I didnt know any better. I do now.

Now these days I've driven ads speakers rated for 150 watts at 8 ohms with monster power amps rated to do 300 watts at 8 ohms and see the clip lights flicker once and a while. No tweeters blown and nothing but sweet sound.

More than anything I dont know why anyone wants to listen to an amp that's crying uncle when used??? Blowing speakers or not doesnt matter.
 
Blown drivers? Hell ya, even set one on fire in my Toyota once, not a great sight at night at 50mph to see flames in the dash speaker cutout lol.
 
damacman said:
...Now, if that were true, it must be true in all cases.
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I don't know what all the heck you just said, but this part is absolutely incorrect.

Unless there's supposed to be a winky winky, smiley face in there somewhere.

Like this guy >>> ;)

Or maybe this guy >>> :p
 
E-Stat said:
Never blown a driver even when I tried. Currently use a 300 watt/channel Ncore amp with vintage New Advents in the garage system.

Poor Henry would roll over in his grave with that knowledge. ;)
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I'm a bass player. One time I was playing a Crown amp bridged to put out 1200 watts into my single 2x12 avatar cabinet. We were playing outdoors on Mercer Island with nothing but a deck railing behind us. We were playing stranglehold. I had the Chorus on and was playing from end to end non stop. This is where I learned the difference between thermal and mechanical failure in a speaker, and why they have cooling fins on the magnet structure.

Thank God it was the last song in the set. Toward the end, my bass got quieter and, as I expected, it then went dead. One speaker had failed followed close behind by the other. When I got home I cut the spider and cone and pulled out the voice coils. The windings on them were loose like a bunch of thin spaghetti draped over the coils.

That is what we call "thermal" failure. :)
 
Back in the early 80's, I killed several tweeters on my Polk SDA-2s with a 100 w/ch Pioneer SA-1040 integrated amp, which I often drove into clipping to the point it's protection circuitry would shut it off. When I replaced it with the considerably higher powered ADCOM GFA-555, the tweeter destruction ended. Since then, I have always had "high powered" amps and have never blown a tweeter.

High Power saves tweeter's lives! LOL ROCK ON, BITCHES!
 
PPstereo said:
Yeah I also never understand these arguments for underpowered amps pose no threats.


More than anything I dont know why anyone wants to listen to an amp that's crying uncle when used??? Blowing speakers or not doesnt matter.
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You proved the very point that you were arguing against.
What would happen to your current system with 300 watts if you turned it up so loud that it would cry uncle; blown tweeter.
Under powered amp? No, overzealous operator.
Read 6) Bigger Amplifiers - in Rod Elliott link above.

My car is under powered and doesn't go fast enough, therefore I destroyed it.
What?
Yes, I pushed it over a cliff to see if it would go faster.
Always buy a car with 5 times the hp you need and it will save your car from premature failure. :)
 
Cogito said:
Back in the early 80's, I killed several tweeters on my Polk SDA-2s with a 100 w/ch Pioneer SA-1040 integrated amp, which I often drove into clipping to the point it's protection circuitry would shut it off. When I replaced it with the considerably higher powered ADCOM GFA-555, the tweeter destruction ended. Since then, I have always had "high powered" amps and have never blown a tweeter.

High Power saves tweeter's lives! LOL ROCK ON, BITCHES!
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Is it possible that if you bought a 545 you would have had the same result?
 
E-Stat said:
Appears you didn't match drivers to amp very well.
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Exactly. It was never a problem in the past because we were always indoors. Two other details: 1. I was competing against two screaming lead guitars. 2. The goal was to get a second 2x12 and actually have a stereo setup.

This happened about 18 years ago, btw.
 
opnly bafld said:
Is it possible that if you bought a 545 you would have had the same result?
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Most likely, as the 545 was no slouch. However, the SDA-2s were a pretty difficult speaker to drive and they dipped into the 2-3 Ohm region at certain frequencies, not something the little Pioneer was designed for.
 
whoaru99 said:
Because it never has been, nor ever will be, an underpowered amp problem. It is an overzealous operator/operator error problem.
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I understand your point. And of course misuse / mis matched gear is a valid reason for the outcome.

I'd simply say with allot of users way back when to this day are none the wiser of their error. I can only imagine how many speakers have been damaged by 20-60 watt receivers or whatever the amp from this problem. Most of this gear used has no clip lights and their operators dont pick up on the damage.

Still goes on to this day with the budget built powered speakers / monitors. I see for sale ads for such speakers with blown tweeters. So now does the blame lie on the operator or the manufacturer?

Many operators of stereo gear dont understand the ins and outs enough to ensure damage is never done.

Kind of in the vein you give a monkey a gun and someone ends up dead do you blame the monkey or who gave it the gun. Allot of unknowns with these scenarios.

And of course I understand there are other failure modes to speakers. If I drive my ads speakers with my 300 watt amp long enough full tilt the voice coils or xover could go into thermal failure. Never mind my hearing lol.

I'm simply in the camp that in general, I'd rather see more power available vs not enough. But so much of all these generalizations depend on people listening habits, gear, state of mind lol so on. No one size fits all.

I just dont see much point, especially in the realm of general consumer home stereo use, arguing over operator error for driving some amp into clipping. They either change their ways, buy a bigger amp, keep buying replacement parts or learn sign language to communicate with the world a bit down the road ;)

So yes I get your point. Your not wrong. This is just my feelings on the matter.
 
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opnly bafld said:
You proved the very point that you were arguing against.
What would happen to your current system with 300 watts if you turned it up so loud that it would cry uncle; blown tweeter.
Under powered amp? No, overzealous operator.
Read 6) Bigger Amplifiers - in Rod Elliott link above.

My car is under powered and doesn't go fast enough, therefore I destroyed it.
What?
Yes, I pushed it over a cliff to see if it would go faster.
Always buy a car with 5 times the hp you need and it will save your car from premature failure. :)
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I love Rod's site btw.

I tell folks wishing to learn about all things audio to check out his articles section.

Probably the greatest audio college one could ever attend.

His and the handful of others dedication to making that info public and having taken the time to do is such a massive contribution.

His 3 way active powered speakers are such a marvel in design. I'd love to hear them.

Reading his article on the 3 key crossover points and how it stemmed from bell telephone was really interesting.

Again as I wrote above. I do get it. I just think it's kind of silly to split hairs on where the blame lies with such a massive I'll informed user base. And feel if more home users simply had more appropriate power to their amps less damage would have been done collectively. But that's just my hunch.
 
All I know is that "operator error" was in force when I first paired a Sansui 6060 (40watts/ch) with Infinity Quantum Jrs (4ohm) and somehow the volume control would get turned up in an attempt to recreate the levels of a Who concert (I was a teenager in the 70's; louder was better!)

Doubly dumb? Sure, I'll cop to that.

The result:
burnt-tweeter.jpg


Here's the other dumb part - it happened on multiple occassions. The Jrs were rated for 25-200W, so I'm pretty convinced that it was clipping that fried those tweeters.
 
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