need help w/ amp combo/head/cab

[matula6661]

Hey, I've been playing bass for about a year now, and I've always just gotten combo amps. Never knew much else about cabs and heads. I have an acoustic B100 combo amp. I'm looking to upgrade to a real set up. On a budget, so I can't buy it all at once, figured I'd buy one at a time. So should I get the head first or cab? I'd like to know if it's possible to hook up my combo amp to a head or cab, for a bigger sound. Whichever one I can hook up for a louder sound, that's the one I'll get first, then eventually sell my B100.
Another thing, can I get some help on which amp head and cab I should buy?? I want to make sure I can hook up a cab or head to the combo amp. I also want to have a good set up going on for the future.
If it helps, I'm jamming with my band in a garage, drums, 1 guitar, vocals, the whole deal. Eventually plan on doing gigs. Thanks a ton.
sorry if it's in the wrong thread

 

[G00D+~VIBES]

Buy used. Craigslist for the cab. Classifieds Here for a head.

Unless you're more specific about what you're trying to achieve, that's about the best I can do.

 

[matula6661]

Buy used. Craigslist for the cab. Classifieds Here for a head.

Unless you're more specific about what you're trying to achieve, that's about the best I can do.

But will I be able to hook up the cab to my combo amp?

 

[Johnny Crab]

You may or may not gain anything by hooking an external speaker up because the amp output puts it in series with the internal speaker so you go from 100 watts into 1x15 to about 50 watts pushing more than one speaker(external speaker must be 4 ohms also so the amp "sees" 8 ohm and will put out about 1/2 of what it did). Pic is from page 11 in the B100 manual.

If you can TRY using another cabinet before buying it and the added cabinet is more efficient than the 15, you might gain some decibels output.