Comment 1 for bug 114372

This speaker symptom cannot possibly be an Ubuntu/Linux issue. According to http://www.harmankardon.com/faq/showfaq.aspx?Region=USA&Country=US&Language=ENG&lstProduct=SOUNDSTICKSII , these speakers use a normal analog output.

What you really should be asking is whether your _sound card_ is configured properly. Are the levels increased properly? Please read http://www.linux-sound.info/alsa/index.php?task=support and tell me the URL of the paste generated by the script linked from that page.