Low sound volume Playback through Headphones

This through my speakers , i plug my headphones through the audio jack on the "SoundForce Vivo 2.1" by Trust company

Things i have tried:-

Updating drivers (there is none for my speakers)
updated system (onboard) sound card drivers.
all my lines in/out are at max volume
all my system volumes and system tray volumes are at maximum

the sound plays back just very low, i have to turn my speakers up full on the volume dial for any form of playback.

any solutions or suggestions? :S

EDIT: Also i have tried plugging my headphones into the rear audio jack and removing my speakers (frustrating at the least) but low playback through that entrance as well.

EDIT 2: I have an Acer Aspire M1640 running Windows 7 Premium

Your onboard sound, I assume is Realtek.
Realtek
You can give the sound an overall boost be enabling the Loudness Equalization.

Also make sure it's set to DVD quality