The Basics: MP3 Speakers

MP3 speaker systems evolved from units that were once known as "multimedia speakers." These speakers started out as add-ons for computers and were meant to improve upon the standard small internal computer speakers that were only capable of delivering basic squeaks, squawks and dings. Since then, "multimedia speakers" has evolved into a product category with dozens of entries.

Today, we use multi-speaker systems for gaming, watching movies on the computer, and listening to audio files and Webcasts. There are speakers that are designed for use with laptops, portable DVD players and, of course, MP3 players.

The vast popularity of portable music players has spurred tremendous growth in the market of MP3 speakers. Each season brings new models, ranging from budget-friendly to break-the-bank prices. There are ultra-compact models, single-speaker systems that rival the rich sound that is often produced by larger multi-component systems, compact utilitarian models, and others that are distinguished by their unusual and eclectic designs.

MP3 speakers are generally small, self-contained systems. They include their own amplifiers and controls and therefore 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 in addition to 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 one set of speakers. Keep in mind that their small stature doesn't necessarily mean lightweight performance, as many of these compact systems can produce amazing -- and unexpectedly -- loud sound.

Multimedia speakers commonly use one of two basic configurations: full-range and satellite. Full-range systems employ one or more speakers in an enclosure to produce a full range of audio, 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 produced.

Satellite speaker systems split up the audio frequencies. They combine the bass frequencies from each channel and send them 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 often 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 that you will likely 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 elsewhere to provide the location clues. Together, the subwoofer and satellites provide the full range of audio reproduction.

Multimedia speaker systems include an amplifier that changes the low-level output of your computer, MP3 player or other device into the high-power wattage necessary to drive the speakers. This amplifier is rated for the number of watts that are produced per channel, as well as the amount of noise and distortion that it contributes to the sound you hear. Generally speaking, the higher the wattage, the louder the speakers will 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 one or the other contributes to a lower potential volume.

How to Shop

Portable multimedia speaker systems are designed to supply 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, which allows you to widen the soundstage for a better stereo image.

Compact MP3 speaker docks often pack a lot into a single housing: A tweeter for higher sounds, a woofer for bass tone and, sometimes, a subwoofer that reproduces even lower frequencies.

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 that is included, if any; look for cases that can store the speakers as well as any necessary cords or accessories. Be aware that it's common for battery-operated speakers to produce a hiss when in use; this can be less noticeable when used outside, but consider the placement and type of use that you intend for your speakers.

Stationary multimedia speaker systems come in a wide variety of configurations, including multichannel systems that are designed for gaming or home theater surround sound. There are two primary ways that multichannel speakers connect to a computer system: via analog line-level outputs on a computer and 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 multichannel information that 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. These numbers tell you how many discrete channels of audio (the first number) and how many channels of combined low-frequency subwoofer information (the second number) the speakers in question can reproduce. 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, which are placed between the fronts and rears.