Speaker wire
A speaker cable ( colloquially speaker cable ) is a usually two-wire electric cable, the speaker terminals of an audio amplifier connects to a speaker. It transmits the low frequency audio signal with the electric power for driving the speakers.
Material
The veins of speaker cables consist usually of insulated copper wire. As a conductor material are also aluminum (see copper-clad aluminum ) or various precious metals and alloys. Aluminium is less suitable because it is more prone to cable breaks and has an approximately 50 % increase in electrical resistance value. Precious metals are also used in high-quality lines, with a benefit with respect to the sonic result is not proven.
In lines with a round profile, the wires are twisted together, as a rule, so that the radiation fields is reduced.
If the two insulated wires additionally surrounded by an outer insulation, one speaks of a speaker cable.
Voltage and current
Depending on the transmitted power may rest on a loudspeaker line dangerously high AC voltage. In the event technology services are entirely transferred to 2000 watts to an 8 -ohm speakers, which corresponds to a voltage of 125 volts. The touch uninsulated cable ends and terminals can cause an electrical accident.
With the usual in the hi-fi technology, significantly lower benefits, however, the touch of speaker cables is safe usually.
Cable cross-section
For the domestic hi-fi or home theater system pairs come from copper wire widths between 0.75 mm ² for short and up to 4 mm ² for longer cable runs (up to about 20 m ) are used. Although higher cross sections offer an even lower resistance, which, however, no longer sound effect perceptible.
In the professional event technology represent cross- sections of 2.5 mm ² the minimum necessary, depending on the required cable cross-sections are used here up to 10 mm ².
End financial statements
Speaker wires are in the home often connected directly without completion by pressure or screw terminals on the amplifier and speakers. The open strand can thereby be protected with wire-end ferrules and cable lugs. Spring pin ( sl " banana plug " ) and DIN connector ( sl " semicolon plug " ) are also often used, whereby the former are often combined with screw terminals.
In professional fields, XLR, jack and Speakon connectors are used as cable termination.
Speaker cable with banana plugs
XLR connector speaker cable
The Speakon system is the default port in the professional PA equipment
DC -way socket
If several speakers operated, they must be attached in the same direction, since otherwise part to cancellation of the sound signal and impaired localization of phantom sound sources ( see also Out of phase stereo).
For the same pin connector poles of the amplifier outputs and speaker connections are known as " Plus" and marked "minus", although AC power is transmitted. Plus and minus are here defined so that when the positive terminal is positive with respect to the negative terminal, the speaker cone moves outward, thus creating a sound pressure maximum. The positive terminal is usually red and the negative pole in black.
The wires are on the speaker line either colored differently, or one of the wires is marked with a label or a riffle of insulation and is usually used as a positive vein.
Audio amplifiers and AV receivers that have an automatic calibration system that detect accidental interchanging of the lines and ask for correction.
Special line types
From numerous cable manufacturers constructions are advertised with special properties such as
- Very large conductor cross-section
- Particularly pure copper ( OFC called - Oxygen Free Copper)
- Exotic materials for conductors, insulation and contacts
- Special cable geometries
- The so-called " burn-in"
- Treatment of the material on the basis of pseudo-scientific ideas
Such cables are visually valent and can mechanically offer advantages (eg in flexibility ). However, as regards the quality of audio playback, as scientific studies have shown that they are not a "normal" technically flawless bifilar copper with adequate distance cross sections superior. The advertised benefits are based purely subjective or pseudo-scientific or based on the inappropriate transfer of findings from the high- frequency technique to the ( low-frequency ) audio signal. There is no verifiable experimental evidence nor sound theoretical derivations.