Yesterday i bought a really nice 2.1 Speaker-system for my computer. I was a bit confused to begin with, because for some reason, the subwoofer didnt work at all, until i turned up all my sources and suddenly it worked. I had no idea why, but i was like: "Yee. I don't care, it works." Then i plugged in my Headset for a skype-call and after unplugging that one (Speakers are on the Rear-inputs and my Heaset on the Front) the subwoofer didnt work anymore. I unchecked some boxes in the Realtek Onboard audio Manager (i dont use a soundcard [yet]) and for some reason it randomly started working again. Today i wanted to listen to some music and another problem came up. The speakers didn't work at all. I can do what i want, they won't work. I was checking and unchecking boxes again, got it to work for like 5 seconds and after opening any audio-file, the Sub stopped. There is Bass on the Satellites and even that bass is pretty nice, but no comparison to the Sub. I'm out of ideas and no Forum Thread could anyhow fix my Problem. To sum things up real quick: The Satellites take over the Subs work and the Sub is not working at all. I tried all the "Bass Management" box thingies, but nothing. I hope you guys can help me.
I had the same issue with the Logitech z623 subwoofer not working immediately after purchase and setup.
What I discovered was that the issue was having the correct setting in your Realtek Audio HD Manager software. You would think that the right setting is to select a 5.1 speaker configuration and then uncheck the center, side and rear speakers so that only the front left and right and subwoofer remain selected. You would think that. I did. And that was wrong.
Apparently these speakers and many others nowadays can separate the subwoofer frequencies on their own. So leave the Realtek set to a 2.0 front left and right configuration. That way it sends all the sound through the one connection that you use to connect your subwoofer to your computer sound card. The subwoofer supplies power and passes along the correct part of the audio to the speakers which connect back to it, and the subwoofer finally works!