So here's a new one for me... I had a moment alone in the house while my wife was away and decided to really turn up my amp. I run a Quilter Mini 101R (the one with the traditional tone stack, not the TriQ) into an open back 1x12 Eminence Cannabis Rex. The amp is 50w, the speaker is rated for 50w at 8ohm, I have it all hooked up correctly (8ohm out on the amp, etc). Cranked the volume to about 1 o'clock on the master (just past the 10w part of the knob) and had the gain at noon (clean but full). Kicked on a couple of my drive pedals, etc. These Quilter Mini's are stinkin' loud, and at slightly above "10w" it's already WAY too loud, even for a band practice or a small show, but no one was home and it was fun. All of the sudden, I detect a faint burning smell. I ignore it for a little while and continue playing another 5 minutes or so. Then it occurs to me that I've never heard this head wide open, so I crank it all the way to the 50 watt setting just to see what that's like, try it clean, with the onboard gain, with some drive and fuzz pedals, etc. SUPER CRAZY LOUD. I'm feeling every note in my body kind of loud. I detect a slightly more present but still not particularly severe burning smell. I cut the volume and sniff around the amp and detect that it is slightly sweet in nature, and it is definitely coming from the speaker cab. I stop what I'm doing, google it, don't come up with anything significant (just a lot of conflicting opinions from forum goers on audio pages, etc.). After about 5 minutes I feel around on the inside of the speaker through the open back and nothing is hot or even warm, nothing feels damaged etc. After a little bit I plug in again at a more reasonable but still too loud for most people volume and everything sounds as it did before I ever cranked the amp. My ears are ringing a little bit from cranking it all the way up but any difference I'm hearing is clearly my now abused ears, not the speaker or amp. In short, my amp and gear still sound essentially the same for me as they ever did. So... what happened? What caused the burning smell?