The Basics: MP3 Speakers

MP3 speaker systems grew out of what used to be called "multimedia speakers." These speakers are a relatively new concept. They started life as add-ons for computers, meant to improve upon the small, internal computer speakers that were only capable of delivering basic squeaks, squawks and dings. Since then, multimedia speakers have evolved to include multispeaker systems for gaming and movie viewing, as well as portable speaker systems for use with laptops and MP3 players.

What all of these systems have in common is that the speakers are completely self-contained. They include their own amplifiers and controls and do not require the separate components found in home audio applications. Multimedia speaker systems generally fall into two main categories: portable and stationary.

Portable speaker systems are usually physically smaller than stationary systems and are often powered by batteries and standard AC power. These systems are primarily used for notebook computers, MP3 players and portable video players. They may also be a good choice if you have multiple computers but only want or are able to buy one set of speakers. Keep in mind that small stature doesn't necessarily mean lightweight performance, as many of these compact systems can produce amazing and unexpectedly loud sound.

Stationary speaker systems are primarily designed for use at a single location. They tend to be larger than portable systems, and they are generally better able to produce higher volumes without noticeable distortion.

Multimedia speakers commonly use two basic configurations: full range and satellite. Full-range systems employ one or more speakers in an enclosure to reproduce the full audio range, and they require larger speakers to make this possible. The advantage of a full-range system is that it only needs two enclosures -- one for each channel being reproduced.

Satellite speaker systems split up the audio frequencies. They combine the bass frequencies from each channel and send them off to a dedicated subwoofer, while mid- and high-frequency audio is sent to the dedicated satellites. This allows satellite speakers to be much smaller than their full-range counterparts, and the larger speakers necessary for bass reproduction can be housed in a specially designed enclosure that is also home to the system's amplifiers and controls.

The low-frequency response of a satellite system's subwoofer tends to be non-directional in nature, which means we humans have a difficult time determining where the low bass sounds are originating. Thus, you can place the subwoofer cabinet in an out-of-the-way location, such as under a table, while the satellites can sit on your desktop to provide the location clues. Together, the subwoofer and satellites provide the full range of audio reproduction.

Multimedia speaker systems include amplifiers to change the low-level output of your computer, MP3 player or other device into the high-power wattage necessary to drive the speakers. The amplifier is rated for the number of watts produced per channel, as well as the amount of noise and distortion it contributes to the sound you hear. Generally speaking, the higher the wattage, the louder the speakers can play. As volume goes up, however, the effects of noise and distortion become more apparent. A good multimedia speaker system strikes a balance between design and playback quality, even if that means lower potential volume.

How to Shop

Portable multimedia speaker systems are designed for two-channel reproduction. They usually contain the two channels in one enclosure, thus making the device very compact and self-contained. A few portables offer the option to detach the speakers, allowing you to widen the soundstage for a better stereo image.

Be sure to consider a portable speaker system's battery life. If it is shorter than you need, you may have to haul around an extra set of batteries, which adds to the weight and expense of the system. Also consider the type of traveling case included, if any. Look for cases that can store the speakers as well as any necessary cords or other accessories.

Stationary multimedia speaker systems come in a wide variety of configurations, including multichannel systems designed for gaming or home theater surround sound. There are two primary ways that multichannel speakers connect to a computer system. The first is via analog line-level outputs on a computer, and the second is with an optical or coaxial digital audio output. A digital connection requires only a single cable to connect the speakers to the computer, but the speakers must be capable of decoding the surround sound information the computer sends out. Keep in mind that not all multimedia speaker systems accept a digital input.

Gaming and home theater multimedia speakers systems are often referred to as 5.1 or 7.1 systems. This nomenclature tells you how many discrete channels of audio (the first number) and how many channels of combined low-frequency subwoofer information are present. A 5.1 multimedia system contains five main channels (front left, center, front right, left rear and right rear) and one subwoofer channel, while a 7.1 system adds two main channels for side speakers, placed between the front and rears.