I have a fairly new ipad and have just purchased Apple ipad Xtreme Black Stereo speakers. I have not used headphones or any other speakers with the ipad up until today. When I attach the speakers the sound is quieter than without the speakers. I have tried the speakers with my laptop and they work brilliantly - amplifying the sound and giving a sound level in excess of the sound from the laptop speakers. I have tried another set of old PC speakers and found the same - they amplify the sound from the laptop, but in the ipad they reduce the level of sound!
I have checked that the Settings in "ipod" has not been limited, and I have checked that the jack is fully pushed in.