L - Length of wire immersed in magnetic field, in meters.
Laser Diode - A semiconductor device which emits a laser beam.
Last Door Arming - A feature found on some security systems that enables the system to suspend itself from arming until the last door of the vehicle has been secured.
LCD - Refer to Liquid Crystal Display
Lces - The electrical inductive equivalent of Cms, in henries.
Le - This is the voice coil inductance measured in millihenries (mH). The industry standard is to measure inductance at 1,000 Hz. As frequencies get higher there will be a rise in impedance above Re. This is because the voice coil is acting as an inductor. Consequently, the impedance of a speaker is not a fixed resistance, but can be represented as a curve that changes as the input frequency changes. Maximum impedance (Zmax) occurs at Fs.
Lead Acid Battery - A lead acid battery is a secondary cell, meaning that it is rechargeable. It is very common in cars and trucks. It contains plates of lead and lead(IV) oxide in a sulfuric acid solution. The lead(IV) oxide oxidizes the lead plate, making an electrical current.
LED - Refer to Light Emitting Diode
Length - Typically in reference to a measurement of the longest part of a 3 dimensional object, used most commonly in custom subwoofer enclosures.
Levc - Driver voice coil inductance.
Lexan - A brand of acrylic plastic. Commonly used in optically clear and translucent colors for custom installation applications.
Light Emitting Diode (LED) - A form of diode that sheds light when connected in a forward biased condition. LED lighting is used in the many applications for status indicator purposes as well was an alternative to incandescent lighting.
Line Level - The standard preamplifier output level of a signal from an audio source other than a turntable. Usually between 100mV and 1V, but may be as high as 5V or more from some preamplifiers.
Linearity - In an audio device, the ability to accommodate the flow of the original source signal without distorting or altering it in any way. A component is linear if it accurately reproduces the source signal regardless of the signal's frequency.
Linearity Error - The deviation in response from an expected or theoretical straight line value for instruments and transducers (speakers).
Line-out Converter (LOC) - A device that converts high level stereo signal into low level (RCA) stereo signal in order to integrate and aftermarket amplifier.
Liquid Crystal Display (LCD) - A type of digital display made of a material that changes reflectance or transmittance when an electrical field is applied to it.
Load - The electrical demand of a process, expressed in current (amps), power (watts), or resistance (ohms).
Lobing - This refers to the radiation pattern of a combination of two or more loudspeaker drivers at a certain frequency(ies) that effects of lobing are of greatest concern, since this determines how well the speaker preserves the tonality of the original recorded content.
Local / Distance Switch - Changes the sensitivity of the tuner. When switched to local (LO), the stronger local stations are received with a higher image rejection. When switched to distance (DX), the weaker, distant stations are received but with less image rejection.
Long Term Evolution (LTE) - An air interface standard of high speed wireless data transmission used 4G wireless data communications. LTE is based on the GSM/EDGE and UTM/HPSA network technologies, although LTE is incompatible with 2G and 3G air interface networks so it must be operated in a separate wireless spectrum.
Lossless Music - Relating to data compression without loss of imformation. FLAC, Apple Lossless (ALAC) and WMA Lossless are examples of lossless compression music formats. For example, they compress a music CD to less than it’s original size, but the resulting file is nowhere near as small as MP3 and AAC.
Loudness - This control allows you to boost the lower frequencies in your music for full, rich sound at lower volumes.
Loudness Control - Intended to boost low frequencies at lower volume levels and should not be used at high volume listening levels.
Loudspeaker - An electro acoustic transducer which converts electrical audio signals at its input to audible waves at it's output. May also refer to a given driver of a multiple speaker system and not to the whole speaker system as might a speaker.
Loudspeaker Compliance - The acoustical and mechanical equivalent of capacitance. Determines how easily a speaker cone/ voice coil assembly will move when an electrical signal is applied to it.
Low Frequency - Refers to radio frequencies within the 30-3000 kHz band. In audio it is usually refers to frequencies in the 20-150 Hz band.
Low Frequency Driver - A loudspeaker specifically designed to reproduce long, low-frequency wave lengths. The driver typically has a large cone, magnet structure, and voice coil. Woofer.
Low Midrange - The range of audio frequencies between 250 Hz and 500 Hz that contains low order harmonics of most instruments and is generally viewed as the bass presence range. When as signal of 300Hz is boosted it adds clarity to the bass and lower-stringed instruments. Too mush boost around 500 Hz can cause a sound of muffle.
Low Pass Filter (LPF) - A network of elements used to attenuate all frequencies above a predetermined frequency. Frequencies below the cutoff point pass without any effect.
Lows - Term which refers to a set of speaker components used to reproduce frequencies below 500 Hz as in a set of woofers. May also refer to the low frequency drivers of a set of separates. Not treble.
Low Voltage Differential Signaling (LVDS) - A type of digital video interface format used in some automotive applications in which a digital video signal is transferred from one or more devices to a screen in the dash over twisted pairs of copper cables. Commonly used for navigation or rear view cameras in modern OE automotive applications.
L-Pad - An L-pad is a passive device which lets you control the output level of the speakers without changing the impedance seen by the amplifier. A constant impedance is not really necessary for the amplifier but if you are using passive crossovers, a constant impedance is necessary to prevent the crossovers frequency from changing.
LPF - Refer to Low Pass Filter
LTE - Refer to Long Term Evolution
LVDS - Refer to Low Voltage Differential Signaling