Well - my speakers caught fire.

[Hopkins]

This is the only time I have seen an example of a speaker hitting its thermal limit before farting out because of excursion (I assume that is what happened).

You are seriously under-powering your cabs. The likely culprit is a clipped signal (to the point of DC) overheating the coils.

Just, no

 

[B-string]

This is the only time I have seen an example of a speaker hitting its thermal limit before farting out because of excursion (I assume that is what happened).



Just, no

I would say we are looking at worn suspension, if the voice coil was in the gap the heat would sink to the motor (magnet) assembly.

 

[Jason Tubbs]

Just, no

Care to explain your disagreement?

 

[BurningSkies]

Care to explain your disagreement?

Underpowering and the nonsense about square waves is completely mythological.

 

[B-string]

Care to explain your disagreement?

Yes we haven't had to do this in almost a week. Maybe we will have to a few more times this week as well.

 

[Hopkins]

I would say we are looking at worn suspension, if the voice coil was in the gap the heat would sink to the motor (magnet) assembly.

I will take your word as gospel, you know alot more about the subject matter than I do.

 

[Jason Tubbs]

Yes, I know a clipped signal isn't DC. I have seen plenty of drivers burned because someone thought a brickwall limiter = speaker protection.

 

[B-string]

If one cares to not read the whole paper here is one important point to take away from the JBL paper:

C. For musical instrument application, where
distorted (overdriven) output may be a musical
requirement, the system should be powered with an
amplifier capable of delivering only one-half of the IEC
rating for the system.

 

[killjeats]

I would say we are looking at worn suspension, if the voice coil was in the gap the heat would sink to the motor (magnet) assembly.

That would explain why the speaker had a rattle to it in practice. They are the original speakers from the 80same and the guy who owned it before me was your typical cover band dad. I'm sure I'm pushing it much more than he ever did.

 

[Gravedigger Dav]

Before I plugged that head into any cab I would have it checked out. I have only seen anything close to this before. Had a power section blow and it put B+ across the voice coils. Since you were still getting sound, I doubt it is that much voltage, but it is suspicious that they got that hot and caused a fire. The second head may have done nothing, but by the time you plugged it in, the speakers were already gone. It was like you were driving a car that ran out of oil in the engine so you started it back up and tried to drive it home.
The speakers are toast (intentional pun), maybe all of them. The head is suspect. Before you do more damage, take it to a tech.
And, I am among those who think a pedal doing that is not at all reasonable. If a pedal were malfunctioning, it might damage any other pedal downstream from it and/or the preamp section of the amp. For the amp to blow the speakes it will always be the power section that does it. How the power section got messed up is another puzzle.

One other thought. It may be that one speaker died and now the impedance has gone all wrong in the cab and causes the problem.

IMHO, you will save money, time, and grief if you just take it to a tech.

 

[Slough Feg Bass]

that is pretty punk rock, you get bonus points for that one, w/ pics even!

 

[KevInDaBassment]

Care to explain your disagreement?

 

[wcriley]

I once saw the dust caps on JBLs in a Fender Twin turn cherry red just before going up in flames. Quite a show that night!

 

[BurningSkies]

If one cares to not read the whole paper here is one important point to take away from the JBL paper:

C. For musical instrument application, where
distorted (overdriven) output may be a musical
requirement, the system should be powered with an
amplifier capable of delivering only one-half of the IEC
rating for the system.

That's pretty much what I'm suggesting about him using pedals that layer distortion. I believe that by massaging your signal you're compressing and while your peak may not be excessive your 'average' output is higher and more consistent for it. That would create more heat and not give the coil as much time to cool.

 

[B-string]

That's pretty much what I'm suggesting about him using pedals that layer distortion. I believe that by massaging your signal you're compressing and while your peak may not be excessive your 'average' output is higher and more consistent for it. That would create more heat and not give the coil as much time to cool.

Yes, but only two of six speakers failed. That would indicate those two speakers started out the gig in a severely weakened condition.

 

[Pilgrim]

You are seriously under-powering your cabs. The likely culprit is a clipped signal (to the point of DC) overheating the coils.

There. Is. NO. Such. Thing.

Discussed many, many, many times.

 

[BurningSkies]

Yes, but only two of six speakers failed. That would indicate those two speakers started out the gig in a severely weakened condition.

Just because the sick antelope are the first to fall doesn't mean that the lions are less to blame.

 

[BurningSkies]

Just because the sick antelope are the first to fall doesn't mean that the lions are less to blame.

^^^metaphorical tech advice for the philosophic amp owner.

 

[B-string]

Just because the sick antelope are the first to fall doesn't mean that the lions are less to blame.

Sure, but I'm off of the theory and back to the specific failure .

 

[AltGrendel]

That's pretty much what I'm suggesting about him using pedals that layer distortion. I believe that by massaging your signal you're compressing and while your peak may not be excessive your 'average' output is higher and more consistent for it. That would create more heat and not give the coil as much time to cool.

After thinking about your comment, I actually understand what you mean. Took me about 5 minutes, but I did catch up. Learn something new every day.

Thanks.