Get it re-coned, you blew it up. This isn't a warranty issue, either. This is a case of abuse. Did you vent the iso box? Greenbacks are not very highly rated powerwise, what amp did you smoke it with?
Heads up to those of you out there who want to build an iso cab to handle a cranked tube amp...use a higher-rated speaker (watts-wise) than the amp can generate...a LOT more. A cranked tube amp will punish even the very best of speakers due to the harmonic density of the signal.
Next time, try using an Eminence Legend, something that take the heat...

Get it re-coned, you blew it up. This isn't a warranty issue, either. This is a case of abuse. Did you vent the iso box? Greenbacks are not very highly rated powerwise, what amp did you smoke it with?
Heads up to those of you out there who want to build an iso cab to handle a cranked tube amp...use a higher-rated speaker (watts-wise) than the amp can generate...a LOT more. A cranked tube amp will punish even the very best of speakers due to the harmonic density of the signal.
Next time, try using an Eminence Legend, something that take the heat...

I sort of agree with this. At least in my experience, the only reason I have seen a guitar speaker blow is when the lows are turned up too high. Now, I suppose if one put an EMG equipped guitar into a clean boost into a cranked 300+ tube watt head with the volume up all the way, then yeah, I suppose the speaker could blow even with lows below 3. But still, I have found it nigh impossible to blow guitar speakers if I keep my lows below 4 or even 5. Then there was the crappy 10 watt solid state amp that someone bought at a garage sale and had me play my edrum kit through for practice... Now that is a good way to blow guitar speakers. :roll:

It is virtually impossible to blow up a speaker in free air no matter what the wattage. This situation says that the use of the isolation box or chamber is probably the culprit. These reduce the amount of cone excursion available to the speaker and because of this the speaker has to slough off the energy asked of it by the signal and it does this with heat rather than regular movement. Heat kills voice coils.

For these boxes I would recommend, as did Moon, a fairly large wattage speaker and one that is very tightly suspended. Also one that has heat fins or a radiator on its magnet.

One has to wonder why Celestions are so popular in isolation cabinets... But certainly, a high wattage speaker would be a whole lot less likely to blow.

I am curious what is the amp output rated in watts and ohms? And what were the speaker's ratings? Is the isolation cabinet closed back or open?

There are many places on the net with iso cabinet info. Some very detailed findings and reviews. All I could find except the Randall iso cabinet seem to offer them with 75watt rated speakers, some Celestions and some others. Some come with a 6" speaker. ALL of the high-end ones talk about the power handling and do not recommend using a high-power tube amp with a low-wattage speaker. There are discussions about this on several BB sites and most will touch on the relative merits as well as the drawbacks of using this type of box.

As I said. Its all about the loading of the speaker in an environment that doesnt allow for complete cone excursion and the resulting heat produced by this situation. This isnt conjecture it is simply physics of sound.