What?
You need to explain your situation a bit better. Actually, a lot better.
If you're talking about a mid/high speaker, it should not be directly connected to the sub in any way.
Sorry about the confusion. So is it possible to use a portable speaker as a replacement to a stereo sound system? Thus being, is it possible to hook up an amplifier and subwoofer to said speaker? The speaker I have is a Big Jawbone Jambox.