Why is there smoke coming from my cab?

[Enron Hubbard]

So I'm playing my rig tonight and a few songs into rehearsal I start to smell a sort of "new car smell" over by where my amp is. At first I thought it was my amp but it didn't seem very hot when I touched it.

By about the 5th song in I started noticing smoke coming from my cab.

The amp was a GK 1001 RB II (700 watts at 4 ohms) and it was set just a bit past 12 o'clock on the master volume.

The cab was an SWR Big Bertha 2x15 (700 watt, 4 ohm cab).

What gives?

 

[Joe Gress]

Check your wires and cables first.

Or is your cab covered with rat fur? Do you have your amp directly on top of the cab, or in a rack? The amp could be hot enough to start burning that stuff.

 

[Enron Hubbard]

Check your wires and cables first.

Or is your cab covered with rat fur? Do you have your amp directly on top of the cab, or in a rack? The amp could be hot enough to start burning that stuff.

I'm using Monster Studio Pro 1000 speaker cable...by "rat fur" I assume you mean carpet covering, yes? The amp is in a rack on top of the cab.

I plan to open it up this weekend to see if there's anything weird going on inside (I just bought it last Saturday).

But what would cause a speaker cab to smoke like that? I've never had that happen to a cab before.

 

[Joe Gress]

I'm using Monster Studio Pro 1000 speaker cable...by "rat fur" I assume you mean carpet covering, yes? The amp is in a rack on top of the cab.

I plan to open it up this weekend to see if there's anything weird going on inside (I just bought it last Saturday).

But what would cause a speaker cab to smoke like that? I've never had that happen to a cab before.

Yup, rat fur is carpet covering.

But I dunno what would cause it to smoke. My guesses were the typical uneducated/uninformed guesses.

Could the driver get hot enough to start smoking maybe? Or perhaps something is rubbing on something else inside and causing enough friction to burn?

 

[svtscruggs]

check your speakers...i have had the voice coil on a cab "lockup" before and the whole thing caught fire...i dumped a beer on it...ha!

 

[Enron Hubbard]

check your speakers...i have had the voice coil on a cab "lockup" before and the whole thing caught fire...i dumped a beer on it...ha!

Hmmmm. What causes a voice coil to lockup?

 

[jmattbassplaya]

I had an amp smoke from pushing it too hard. It was pretty rock n roll.

 

[Implosion]

Have you turned your tweeter all the way down or almost totally off? If you turn your tweeter totally off there's a chance that your crossover might fry. When turned down the resistors start to heat-up and depending on the design, components and the type of signal you are sending to the cab, the heat might be too much for the system to dissipate. So if you turn your tweeter totally down be sure to check from time to time (at least in first few rehearsals) if your crossover plate starts to heat up (you can feel the heat with your hand).

 

[alexclaber]

Your amp has enough power to toast your woofer voice coils, particularly if you push the lows too hard. Or if you have your tweeter turned down but are cranking the highs you could have burnt out the L-pad.

Alex

 

[Enron Hubbard]

Thanks, guys...the tweeter is up around 10 o'clock I believe and seems to be working fine.

I turned the amp down a bit and finished rehearsal without any incident, but I was afraid to turn it up much after that.

I didn't hear any distortion from the speaker and it seemed to work fine...just not quite as loud as I would like (the master volume was at about 1 or 2 o'clock before...I dialed it back to just a hair below 12 o'clock) Is it possible that I won't need to replace my speaker(s) or am I just screwed?

 

[vinxbass]

I was pushing an Elector Voice speaker cab once too hard and it caught fire from the speaker. Your speaker is most likely fried.

 

[Pilgrim]

The amp was a GK 1001 RB II (700 watts at 4 ohms) and it was set just a bit past 12 o'clock on the master volume.

The cab was an SWR Big Bertha 2x15 (700 watt, 4 ohm cab).

What are they now? Did they expire with the release of magic smoke?

You know the magic smoke theory, right?

 

[Dan Knowlton]

check your speakers...i have had the voice coil on a cab "lockup" before and the whole thing caught fire...i dumped a beer on it...ha!

What a waste! NOT the cab....

Dan K.

 

[michael_atw]

Someone accidentally threw it in your fireplace?

 

[B-string]

Maybe those SWR (Fender?) watts were not an RMS rating (like the G-K). IF it didn't say 700 watts RMS then the the G-K might have twice the rated output that the cab can handle.

 

[Let It Fall]

built in effects?

 

[anderbass]

Unscrew your L-pad on the back. I'm thinking you'll see/smell the cross overs burnt.
The L-pad on my old Goliath-2 burst into flames during a gig. I bypassed around mine and went on to use the cab (w/o a tweaker) for years.

 

[Enron Hubbard]

Thanks for your help guys.

So I went back last night to take off the grill, check the speakers, etc.

I pushed on the speakers to see if I could hear any skritching or lack of movement and they seemed fine.

I did notice one of the wires had come loose from one of the speakers. I don't know if this was from me removing the speaker (I don't think it was considering the position of the loose wire) or if it was disconnected when I was playing through the cab the other night.

If only one speaker was firing then it would have been 350 watts at 8 ohms instead of 700 at 4 ohms and the amp puts out 450 watts at 8 ohms...so that would have been too much power for it.

Anyway, I reconnected the cable, put the speakers back in the cab, put the grill back on and let 'er rip. I put the volume where I had it when it was smoking the night before (which is louder than I'd normally run it) and it seemed a little louder and no smoke or issues.

I backed the volume off to about where I'd normally set it and played aggressively for about 20 minutes without a hiccup.

So it seems like everything is good to go. I'll probably replace the speakers in a few months before we start playing out of town just to be on the safe side.

 

[Enron Hubbard]

Unscrew your L-pad on the back. I'm thinking you'll see/smell the cross overs burnt.
The L-pad on my old Goliath-2 burst into flames during a gig. I bypassed around mine and went on to use the cab (w/o a tweaker) for years.

I'll check it out. The tweeter seemed to be working fine though, but I didn't sweep through it so I'm not 100% sure.

I couldn't see it through the padding so I'll remove the plate and give it a look. Thanks.