I currently own an Ashton 40 watt bass amp. On the back of it is a jack with 'External Speaker' and '4-8ohms' below it. My question is: Does this mean I can attach an extra cabinet to it? I've read that it is possible to attain more loudness doing this but would it be worth doing? I assume if I bought a cab I could always buy a head later on. (Unfortunatly I didn't get manual with the amp) This leads me to another question: When looking through catalogues, the descriptions for the heads always say 'xxxwatts at 4ohms' or something similar. Does this mean you have to match the watts of the head and cab or do you only worry about matching the ohms? Thanks.