Amp and speakers blown

My wife turned on our system the other day and after a few minutes everything went quiet. The Unison Research Unico was dark. After I replaced the fuse (which was blown) at the power cord receptacle in the amp, it blew again.

I took it out of the system to get ready for the repair guy and put the basement vintage reciever into my system. I then noticed that the woofer on the right channel speaker was not working (Totem Model 1 original biwire). Note that I was running the speakers biwired from separate terminals on the amp.

Does anyone know whether this driver is easily replaced. Should both L and R be replaced for better matching? Should Totem do it? Is it worth upgrading to the Signatures while they are at Totem if I send them there? Any other thoughts or suggestions?

Surely you would want to replace both woofers; as you would want them to match.--((A new one and and an old one are not a match.))--My condolences.