Weird Ultrabase X6 Sound Problem

[danage]

Here is a strange problem with my Ultrabase X6:

When I got the Ultrabase, there was no sound from the built in speakers because I plugged in external speakers in the back - normal behavior I figured: The internal speaker turns off when external speakers are connected.

Today, suddenly, the Ultrabase starts playing WHILE external speakers are connected. Is this normal behavior? How can I turn the Ultrabase sound off?

Is my Ultrabase defective (Contact switch in headphone jack)?

I am using Linux.

Thanks!

[732]

I was gonna say you might have a bad plug for the external speakers but then I saw you're using Linux. I'm pretty sure it's your audio options, try alsamixer etc. Linux will let you choose whether to turn ultrabase speakers off or use them together.