"Are the speakers meant to run with the subwoofer?"
No, the HK subwoofer needs SoundSticks for proper operation.
Although HK designed the subwoofer, SoundSticks, and the "ball type" Apple Pro Speakers, those "balls" are digital audio devices that work only with proprietary digital audio cards that Apple integrated in select Macs circa 2001-2004--some late model G4 PowerMacs and the first few "flat panel" G4 iMacs. Apple then dumped the tech to move to optical digital instead.
Look at the plug on the Apple Pro Speakers. That 2.5mm ring-sleeved plug won't fit any equipment that you own. And that plug would be only one hurdle. (No, you can't just chop it off and use a standard 3.5mm plug instead. There's a proprietary chip in the cable, too. And the speakers themselves need a digital rather than an analog signal. Etc.) Some people nonetheless like the HK look and have documented what you need to do to convert these old HK devices for modern equipment. Some reading for you:
http://www.racketboy.com/forum/viewtopic.php?f=28&t=42272