q3_abhi is rite...
BASS - Low frequency sound; typically frequencies below 185Hz.
WATT - the normal electricity term.....The scientific unit of electrical power; a rate of doing work at the rate of one joule per second. Commonly used to define the rate of electricity consumption of an electric appliance.
here u can know more about stuff like RMS in speakers n all - *en.wikipedia.org/wiki/Audio_power