Audio volume far too low on Sony laptop

I am new to Ubuntu. I recently installed it on my Sony Vaio laptop to replace Windows 7 (audio worked just fine in Windows). I have spent a long time searching for solutions and adjusting settings. I have adjusted the levels in alsamixer and Pulse Audio Volume Control, but even with all levels maxed the most I can get is very faint sound (barely audible) through headphones and no sound at all through the laptop's main speakers.