At the gig last night my amp pooched during the second set. I finished the night through the PA. At the end of the night i checked it again and it was still dead. This morning it works, seemingly fine. 4 ohm EA Whizzy 12m cab driven through a speakon cable by a Thunderfunk TFB420. Is there a protection circuit in the speaker?(bi-metal strip) I was running everything half open, with 40hz and below rolled off on the parametric. Anybody know what's going on?