Stackable 4 mm banana plugs connected to a loudspeaker

A banana connector (commonly banana plug for the male, banana jack for the female) is a single-wire (one conductor) electrical connector, widely used in science laboratories for temporarily joining wires to equipment. It consists of a cylindrical metal pin about 25 mm (one inch) long, with a diameter of 4 mm, which can be inserted into a matching 4 mm socket to make an electrical contact. While it is also called a 4mm connector (likewise 4mm plug or 4mm jack, as above), there are also other sizes used for other applications. The pin has one or more lengthwise springs that bulge outwards slightly. These press against the sides of the socket, improving the electrical contact and preventing the pin from falling out. The curved profile of these springs is probably the origin of the name "banana plug". The other end of the plug has a hole that accepts a length of flexible insulated equipment wire, which is either screwed or soldered into place. An insulating plastic cover is usually fitted over this end. Image File history File linksMetadata Banana_plugs_speaker. ... Image File history File linksMetadata Banana_plugs_speaker. ... A wire is a single, usually cylindrical, elongated strand of drawn metal. ... Electrical conduction is the current (movement of charged particles) through a material in response to an electric field. ... An electrical connector is a device for joining electrical circuits together. ... The scope of this article is limited to the empirical sciences. ... This article is in need of attention. ... This page discusses common devices known as tools, for other meanings see Tool (disambiguation) Modern hammer A tool is, among other things, a device that provides a mechanical or mental advantage in accomplishing a task. ... Mid-19th century tool for converting between different standards of the inch An inch is an Imperial and U.S. customary unit of length. ... For the geometric term, see diameter. ... It has been suggested that Coil spring be merged into this article or section. ... Screws come in a variety of shapes and sizes for different purposes. ... A solder is a fusible metal alloy (often of tin and lead, although lead-based solders were outlawed in many parts of the world in the 1980s), with a melting point or melting range below 450 °C (840 °F) and is melted to join metallic surfaces, especially in the fields... // Definition An Insulator is a material or object which resists the flow of electric charge. ... Plastic covers a range of synthetic or semisynthetic polymerization products. ...

The wide end of a 4 mm plug often has a 4 mm hole drilled in it, either transversely or axially, to accept the pin of another 4 mm plug. This type is called a stackable 4 mm plug.

4 mm plugs are frequently used to terminate patch cords for electronics laboratory equipment. They are also sometimes used as the plugs on the cables connecting the amplifier to the loudspeakers in a hi-fi sound system. It is a cord designed to connect between 2 computers as a bridge. ... For the British rock band of the same name, see Amplifier (band) An amplifier can be considered to be any device that uses a small amount of energy to control a source of a larger amount of energy, although the term today usually refers to an electronic amplifier. ... Closeup of a loudspeaker driver Wall-mounted loudspeaker. ... High Fidelity is also the title of a book by Nick Hornby and a film directed by Stephen Frears, based upon Hornbys book. ... Sound system has multiple meanings: A sound reinforcement system is a system for amplifying, reproducing, and sometimes recording audio. ...

Where electrical safety is an issue, due to the presence of higher voltages and/or currents, various kinds of protected plugs and sockets are available. These have sliding covers on plugs and/or other devices to protect the user from accidental contact with live conductors, but are still largely compatible with the original design.