Stereo Wiring Blues - **HELP NEEDED PLEASE**

[ashx2]

I picked up a Pioneer KP-A100 cassette stereo. It has the wires handwritten on the top of the unit. They go like this:

Blue= Void
Grey= Right Spkr
Green= Left Spkr
Red= 12v power sourch
Blk= common ground

When wiring this unit up, shouldn't there be additional ground wires for the speakers? Or does the positive side of the spkr wire connect up to the wire coming out of the back of the stereo and the ground side of the spkrs get wired to common ground.

It's been a long time since I played w/stereo equipment........and I'm beginning to remember why.

Anybody have a clue as to how this should be wired?

Thanks,
Greg