What is going on with my computer speakers?

Right-click the little speaker icon, and go to Volume Mixer. Sometimes, different programs have different settings, and they occasionally get “bumped” and cause oddness like that.

@jerv Here’s what I’ve got to work with.. What is “line in” in that image? Could that be the problem?

Possibly. Line In is usually a microphone, but I have used it for other things.

Uncheck the Mute box and see if the sound comes back. It may be soft since the volume slider is set low, but I suspect that that is the issue. let me know how it works for you.

Dang it. That didn’t work. :/

Sounds like internal speaker problems. Some of the higher pitched frequencies are probably all whacked out. Have you tried simply resetting?

If it’s garbled/muffled try, one-by-one, pulling whatever speaker plugs you have out of the chassis and work them back in. Plug them out and in a couple times to scrape through any oxides/films. [ I know that’s always my suggestion, reseat the connector! Rust never sleeps… ]
Also if they are powered speakers check the power connection into the speakers. Some powered speakers will just not make a sound if there’s something bad with the power and some will make a muted/awful sound.