You could try contacting Energy or their distributor and ask them what you should do. They might provide you with an RMA number and have you return the speakers for repair, or give you advice on how to fix them yourself.

You might be able to unscrew the drivers to gain access to the interior of the speaker and fix this yourself. If you attempt to go the DIY route, you should ask Energy if they use any damping compound when mounting the drivers in the cabinets (find out what kind if they do.) Some manufacturers apply a bead of caulking compound around the outer ring before mounting the driver to the cabinet. You should also find out if the damping material that has come loose is stuck to the inside of the cabinet with an adhesive (find out what kind if they do), or just loosely packed. When closing things back up, be mindful not to over tighten the mounting screws and ruining the wood or MDF.

But, contacting the manufacturer is probably the first and best thing to do. If something goes wrong, better that they should be the ones and have to fix it, rather than you messing up and being stuck with damaged speakers and no one to blame but yourself and some dopey guy on the Internet who said you might be able to fix it yourself.

You probably could fix it yourself. From one dopey guy. It's a speaker cabinet, not something like a complex LP/Cd demagnetizer. Ya reach in through a driver ya romve and fix it, just like when they made the thing

That would be quite a coincidence that three days ago, both speakers let loose with their internal damping, and both have the same look through the port.

Have you looked there in the past and it didn't look like that?

I'm also a little dubious that both tweeters would be obstructed in the exact same way and at the exact same time to yield the exact same lose of sound quality.

Before mucking with the speakers, I'd suggest listening to them with a different source feeding them and see if the problem travels with the speakers.

I wonder, really, if there is a problem upstream that you may be assigning to the speakers, but could more likely be a problem in your signal path.

So, try a switch of source first.

After re reading it, how does the material block the tweeter, if you are looking through a baffle port? ain't the tweeter on the front baffle board, aimed out? Maybe you smoked both tweeters, with a clipping amp?