Sudden muffled sound on imac
My computer is an iMac (Retina 5K, 27-inch, Late 2015) and I've got a problem of sudden muffled sound from the built in speakers.
Sound through headphones is fine. I did a clean install of OS X to an external USB drive to see if the issue was software related, but it's exactly the same when running out of the box software with nothing else installed.
To describe the sound, I would liken it to having no mid and high range frequencies.
Given that the sound via headphones is ok, I would think the actual audio chip is ok, and the speakers themselves have failed. Th only other suggestion would be the disconnect that occurs when unplugging the headphone socket, although I would think this is probably ok as I can't see why I would be getting low frequencies, but not mids and highs.
Anyone got any suggestions?
iMac, macOS Mojave (10.14), iMac (Retina 5K, 27-inch, Late 2015