An amp cabinet can add depth and volume to the tone of your musical instrument, but it is important to choose the best type of cabinet for your application. Before you take any steps toward choosing an amp cabinet, you need to take the initial step of determining what type of amplifier you want. Amps come in many different sizes, measured in watts, and each one has a different purpose and sound.
For smaller applications, such as playing at home or in small spaces, a combo amp may be the best solution. The combo amp meshes the amplifier head--or power unit--directly to the amp cabinet. Usually the amp cabinet contains one or two twelve inch (30 cm) speakers, and can produce sound of clear quality for smaller settings. Beyond the combo amp, it becomes necessary to purchase an amp head and an amp cabinet separately.
Amp heads come in a variety of wattage specifications, ranging from 50 watts on less powerful models to over 200 watts on very loud and powerful models. If you are considering the less powerful wattage for smaller gigs and medium-sized rooms, consider an amp cabinet that contains two 12-inch (30 cm) speakers, known as a 2x12 cabinet. These are generally rare for guitar use, but they are not impossible to find and may suit your needs perfectly.
Beyond the 2x12 cabinet, you will venture into the world of the full cabinet. This type of amp cabinet will contain four speakers, either 12-inches(30 cm) or 10 inches(25 cm). An amp cabinet of this size will work well for larger gigs, and you will generally want to use it in combination with a 100 watt amp or higher. This set-up, known as a half-stack, will produce very loud sound and will add depth and character to your sound. Unlike a smaller amp cabinet--like a 1x12 or a 2x12--a full cabinet will produce a fuller, louder wall of sound to be amplified over large areas, whereas smaller amp cabinets will produce less sound with less overall depth and clarity for large spaces.
For extremely large performance spaces, a full stack may be the best choice. A full stack combines the amp head with two 4x12 cabinets stacked on top of each other. At this level, you will want to wear ear protection, as the sound produced by a full stack can damage your ears. A full stack is a good choice for large concerts, though you can use them in smaller spaces, too; just prepare yourself for an overwhelming amount of sound.