Odd. This is what I see when I go to larsonsound.com.
Perhaps someeone else will have an idea of what you can do. You could try clearning your DNS cache.
That's pretty much what I get, though mine has a few headers at the top. I did notice that the certificate had today's date on it, though. Perhaps it was renewed shortly after the OP tried to get on the site. It would be quite a coincidence, but anything's possible.