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Well - my speakers caught fire.
- Thread starter killjeats
- Start date
Well, who *doesn't* like a good "amp on fire" story? Old old-timers all have the tale of the magic smoke to tell, I suspect.
alexclaber
Commercial User
This thread is like an amazing mix of some correct suppositions and many wrong ones - like a flat earth society visit to CERN... 
It doesn't matter if a speaker is rated for 1000W, it's certainly possible to blow it with a 100W amp. That might sound crazy but there are two big reasons behind this:
1. The power handling rating of a speaker is actually a voltage rating with bandwidth limited pink or white noise, converted to a power rating by squaring the voltage and dividing it by the nominal impedance. The true power that's flowing is much less than the nominal power and in the real world the true power to nominal power ratio varies significantly depending on the signal going in. And the ability of the speaker to dissipate heat varies with the signal which is going in. So once you figure all those variables in you can see that in some conditions the speaker will fail with much less power than its claimed power handling rating.
2. The power output rating of an amp is again an approximation based upon tests done by the manufacturer. The actual maximum power output available will vary significantly depending on the amp design, how it was tested, the signal applied and the load (speakers) that it's driving. So once you figure in all those variables you can see that in some conditions the amp will put out much more power than its claimed power output rating.
Put both those reasons together and you can see that when you get a perfect storm, a low power amp can destroy a high power speaker.
It doesn't matter if a speaker is rated for 1000W, it's certainly possible to blow it with a 100W amp. That might sound crazy but there are two big reasons behind this:
1. The power handling rating of a speaker is actually a voltage rating with bandwidth limited pink or white noise, converted to a power rating by squaring the voltage and dividing it by the nominal impedance. The true power that's flowing is much less than the nominal power and in the real world the true power to nominal power ratio varies significantly depending on the signal going in. And the ability of the speaker to dissipate heat varies with the signal which is going in. So once you figure all those variables in you can see that in some conditions the speaker will fail with much less power than its claimed power handling rating.
2. The power output rating of an amp is again an approximation based upon tests done by the manufacturer. The actual maximum power output available will vary significantly depending on the amp design, how it was tested, the signal applied and the load (speakers) that it's driving. So once you figure in all those variables you can see that in some conditions the amp will put out much more power than its claimed power output rating.
Put both those reasons together and you can see that when you get a perfect storm, a low power amp can destroy a high power speaker.
I say it is better to send the flat earth society people to the ISS. There could theoretically be hadron collisions and pentaquarks on a flat earth, but a trip up to the space station settles that one pretty quickly.
Now deniers of the ancient astronaut theory is another issue, the vatican has been doing everything possible to keep that suppressed for quite some time.
Now deniers of the ancient astronaut theory is another issue, the vatican has been doing everything possible to keep that suppressed for quite some time.
This thread is like an amazing mix of some correct suppositions and many wrong ones - like a flat earth society visit to CERN...
A fairly typical TB thread then?
This thread is like an amazing mix of some correct suppositions and many wrong ones - like a flat earth society visit to CERN...
It doesn't matter if a speaker is rated for 1000W, it's certainly possible to blow it with a 100W amp. That might sound crazy but there are two big reasons behind this:
1. The power handling rating of a speaker is actually a voltage rating with bandwidth limited pink or white noise, converted to a power rating by squaring the voltage and dividing it by the nominal impedance. The true power that's flowing is much less than the nominal power and in the real world the true power to nominal power ratio varies significantly depending on the signal going in. And the ability of the speaker to dissipate heat varies with the signal which is going in. So once you figure all those variables in you can see that in some conditions the speaker will fail with much less power than its claimed power handling rating.
2. The power output rating of an amp is again an approximation based upon tests done by the manufacturer. The actual maximum power output available will vary significantly depending on the amp design, how it was tested, the signal applied and the load (speakers) that it's driving. So once you figure in all those variables you can see that in some conditions the amp will put out much more power than its claimed power output rating.
Put both those reasons together and you can see that when you get a perfect storm, a low power amp can destroy a high power speaker.
Right on----- especially since a change (shorted turns) in the nominal impedance will cause more current to flow. The voltage drop across the failure point is where the heat shows up----- just one scenario.
Paper cones have a paper base but the material is a complex formulation. They aren't simple paper. I wonder if there is something in the cones or excessive dope on the cones that somehow acted as an accelerant.
Seems to me one of the speakers failed changing the impedance of the rig (went below the 4ohms) and the amp blew the speaker...
This is nuts. If you follow the OPs posts, he said the cones were going anyway. He already said the amp was fine. GIven the evidence on hand, it seems the cones were ready to crap out anyway. Old, dried out, sounding like they were starting to rip..... You run an amp into a cab like that at higher volumes, its gonna blow out. In this case, it went up in flames. All this talk about pedals and underpowering will never end, y'all can go back and forth for days. Literally. In the end, none of that matters here in the OPs situation IMO. I get where you guys are talking about compression and clipping, but again, I dont think that was the main problem at all. Someone earlier said it, its like he was trying to run his engine without enough oil.
Everything else is a pissing contest or he said she said.
Everything else is a pissing contest or he said she said.
Funny you should say that. It really happened to me in about 1972. I had bought an old Super Showman as a backup to my V4B and decided one night to take it in instead of the Ampeg which I left in the trailer.
Midway into the first we were playing Smoke on the Water and I smelled smoke. I turned around to see smoke coming from the amp. I turned it off and we took a break so I could swap amps.
Turned out the fabric wrap on a wire was touching the chassis and the vibrations were rubbing wire against the chassis. It sparked and set the fabric wrap on fire. Luckily, I had turned it off in time so no damage was done. But the irony of the song we were playing at the time made it a "special moment."
I said that and IMO you are correct.
