You can amplify your bass in two basic ways, with either a separate speaker and amp, or with a combo amp.

• With a separate speaker and amp. The amp and speaker come as two separate units and are connected via a speaker cable. The advantage of buying separate units is that you can get an amplifier from a company known for making good-quality amps and a speaker from that specializes in speakers. Additionally, the separate amp and speaker are more powerful, and they allow you to mix and match different amps and speakers.
• With a combo amp. A combo amp houses both the speaker and the amplifier in one unit, eliminating your need for a separate speaker. The combo amp is more portable than a separate amp and speaker.

You may want to start with a combo amp that has between 50 and 100 watts of power; it'll run you anywhere from $300 to $1200. That's enough for practicing at home, rehearsing in the garage (get the car out first), and playing at the local pub. (Hint: Madison Square Garden is not a local pub, even if you live in New York City.) If you start playing bigger venues — at parties and weddings — go for a performance amp and speaker with at least 300 watts. Yes, they're pricey (from $500 to $2500 and beyond), but they're well worth it. You want to feel the rumble, don't you?