So my amp started making that fizzy, flabby, torn speaker noise. While investigating the sound got really low in volume and distorted all of a sudden and then the smell of something clearly burning filled the air. I shut it off and got a look at the back and the paper of the speaker had a clear rip down the top and around the place where it is attached to the magnet or whatever it had come off too some how. Looked jagged. Clearly I need a new speaker, but is that all it could be? Amp itself ok? Amp is a Mesa Mark IV.
Most amp power is lost to heat.

Most speakers fail due to overheating of voice coils, sometimes actually bursting into flame briefly. Your amp may be just fine; but you'll want to make sure that you have a speaker capable of handling the power of your amp.
That's crazy.

Stock speaker in a Mark IV should not do that. That amp should be able to handle anything you throw at it. The only thing I can think of is that you had a power tube go South or probably even red-plated and it caused a huge mismatch in power. Even then, I still feel like that would be unlikely to happen to the speaker.

Hot room shouldn't affect things too much.

But hey Faux, it is still good to see you again. If you don't get any better responses here I would either try contracting Mesa Boogie, post on the Boogie boards (http://mesaboogieampforum77319.yuku.com/) , or post this problem in the GGnA Who To Listen To Thread.
sounds like you need a tech.

if i were in your position i would isolate the speaker as being the cause by using it with another amp. then i'd see if the amplifier is working fine by testing it with other speaker cabs.

it sounds like you have visually confirmed the speaker is toast with the ripped surround, this is unusual because a guitar speaker's voice coil doesn't usually extend beyond the coil gap and this would make it hard for the suspension of the speaker to dramatically rip. you would also need to be cranking the amp at a pretty high volume to blow the suspension of the 90 watt rated speaker. the suspension ripping/breaking would also not explain the smell you describe, if anything the voice coil should have burnt out to explain that smell (something like a burned resistor in the amp could have caused that smell too).

it is hard to isolate the problem off of what you describe. if you see the speaker structurally damaged then you cannot deny there is a speaker problem, but i am unsure as to the extent of the damage to the speaker or if there is or is not some problem with the amp.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
Last edited by gumbilicious at Jul 23, 2014,
argh ok. It seemed like a process if that makes sense. Like I identified the flabby sound, played a bit to check it out, amp cut out, went back up then down, then smell in like 3 minutes. Amp was at maybe 6 when it happened. Thank you all for the help i'll post on the mesa forums and I guess I'll have to take it to a tech. =(
The first thing I would do is what gumbi just suggested. I'd disable the internal speaker and just run a speaker extension cabinet off the amp and watch the tubes very closely while you play. A burnt plastic smell unfortunately may indicate something fried on the circuit board itself.