I have sound from my Dell now, but the volume is next to nill. There are many jacks on the back for speakers, but I don’t seem to be able to find one that gives me adequate volume. My jack plug, is in the green one,what others can I use. I have two larger speakers with their own jack, the speakers I’m using now, have two small speakers with one jack. System sounds are okay, but not the add on speaker’s volume.