Capsule speakers are small, portable speakers that can connect to any portable audio device, such as an MPEG Audio Layer-3 (MP3) player, mobile phone, or portable gaming console. Likewise, connecting to a laptop or notebook computer typically will improve both movie and audio experiences. These speakers are designed to be compact enough to be carried almost anywhere, thereby enabling amplified audio access to portable music and video without the use of headphones.
There are many varieties and designs of capsule speakers in the portable speaker market. Some brands feature two speakers with left and right channel sound, while others come as a single speaker. True capsule speaker systems have a mushroom-shaped design. At only several inches or centimeters tall and weighing about 7 ounces (about 200 grams) each, capsule speakers typically are easy to maneuver and place wherever they are needed and are easy to stow when they are not.
Also known as pop-up speakers, many are designed to be expandable, creating a few inches or centimeters of space between the base and the speaker head. Expanding the speaker allows more air to pass in and out of the speaker, which helps create a clear sound and vacuum bass effect. For models that come with left and right speakers, the bottom base of each speaker is usually magnetic, allowing the left and right speaker to connect, thereby forming an egg-shaped speaker. This makes the speakers easy to transport and store.
Capsule speakers are fully wired and connect together with a standard 3.5 mm headphone output jack. This allows the speaker to connect to any device with a headphone input. With older versions of capsule speakers, audio cables can generally get messy and tangled; however, newer models allow the audio cable to be stored under the base of each speaker when not in use. Some brands have a "Buddy Jack" feature that allows one set of speakers to connect to another, thereby forming a chain of capsule speaker audio.
Audio output is also available via a universal serial bus (USB) cable, which also charges the speakers when attached to a computer or a USB-charging adapter. A light-emitting diode (LED) will show if the speakers are charging or if they are fully charged and ready for use. Once fully charged, built-in batteries usually last for eight to 12 hours of use, depending on the speaker brand and volume setting being used. Volume controls on most speaker models are fully integrated with the audio device and come with controls directly on the speakers.