HP P6080-63001 - Maxtor DiamondMax Plus 40 GB Hard Drive Getting Started page 52

Audio and speakers (continued)
Symptom
Volume is very low or
unsatisfactory.
48 Getting Started (features vary by model)
Possible solution
Make sure you connected the speakers to the Audio Out (lime
green) connector on the back of the computer. (Additional
audio connectors are used for multiple-channel speakers.)
Detached non-powered speakers (speakers without a separate
power source, such as batteries or a power cord) do not
produce satisfactory sound. Replace the non-powered speakers
with powered speakers.