Bass Amp Basics
Bass Amp Setups
Bass amps consist of several different components. And, bass amp rigs, as they are called, can be purchased in several different configurations. In this bass gear article, I will explain to you the main components of bass amps and the ways you need to combine them. In other articles I will go into more detail about each bass amp component.
The Main Components of Bass Amps
The two main parts of a bass amp are the head and the cabinet.
The bass amp head, or head, is the part housing all the main electronic components of the bass amplifier. The head is the part of the amp into which you plug your bass guitar.
The bass speaker cabinet, or just cabinet, is the box enclosure housing the speaker or speakers. The output of the bass amp head is sent to the speaker cabinet.
The head and cabinet can be bought separately. Other times the head and cabinet are combined into one unit called a combo amp.
Bass Amp Heads
The head of a bass amp can be divided into the preamp and the power amp. Many times these come together in one unit; other times they come as separate units which you must link together. Let me break down these two parts of the bass head...
When you plug your bass into the bass amp input the first place your bass signal goes is to the preamp. The preamp shapes and manipulates the bass signal it receives in various ways. It might make it sound brighter or muddier, or it might make it sound boomier or brittle. The preamp can make subtle or drastic changes to the sonic characteristics of the input signal.
Preamps are commonly designed with a particular instrument in mind. A guitar preamp is designed to make the tonal properties of guitars sound good. A bass preamp is designed specifically for bass. Always be sure to get a bass preamp unless you know for sure you want something else.
Bass Power Amps
Once the input signal has been shaped and colored by the preamp, the bass signal is sent to the power amp. The power amp takes the signal from the preamp and essentially makes it more powerful. The power is needed to physically move, or drive, the speaker in the cabinet. So, the amplified signal is then sent to the speaker in the cabinet.
A bass cabinet is a box containing one or more speakers. Most bass cabinets are simply constructed. Cabinets are usually wooden boxes covered with carpet. The speaker is screwed inside and covered with a protective grill.
Cabinets come in many different sizes. The size is usually described as the number of speakers and the size of the speakers in inches. A 1 x 15 cabinet means it contains one 15” speaker. A 4 x 10 cabinet contains four 10” speakers.
Cabinets are rated in terms of how much power they can handle coming from the bass head. You can damage the cabinet if you send too much power to it.
More bass cabinet info is in the bass cabinet guide.
A stack is a head and cabinet stacked together. A full stack consists of two cabinets with a head on top. A half stack is just one cabinet with a head on top.
What Bass Amp Setup Should I Get?
Any bass amp setup you buy will need to have a preamp, a power amp (these two are often combined in a head), and a speaker cabinet. The easiest thing for beginners to buy is a bass combo amp. That way you can be confident all the parts are there, they are matched to one another, and they are hooked up properly. All you have to do is plug in your bass and turn it on.
Most combo amps are not very powerful and are better suited for practice, rehearsal, and smaller gigs. Being able to hear yourself over a drummer will be a main concern. Drums can be loud.
Another downside is bigger combo amps can be heavy and bulky. There’s nothing quite like carrying an amp that weighs as much as you do up a flight of stairs at 4:00 AM! And, don't forget to make sure your amp will fit into your car.
Buying the bass head and cabinet separately has advantages, but can be more complicated. Firstly, you will usually get more power (that is, more volume) from having a separate head and cabinet.
Having separate components allows you to upgrade one piece at a time or slowly add on more pieces. Going modular may make buying new gear easier on you financially.
You also have more options with how you match the sound of the head to the sound of the speaker. This can be a long, expensive process of trial and error. You might like that, or the many possible configurations there are might overwhelm you. And, hooking up a head and cabinet can be tricky.
Regardless of what you get, it’s a good idea to understand the ins and outs of bass amps.