Introduction

Head Units

Cassette Receivers
CD Receivers
CD Changers

Speakers

Amps/Crossovers

Terms

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Chadwick Johnson

The following terms are here for your information. These words are linked from other pages on this site for ease of use. This is an alphabetical listing. Use your back button to return to the top of the page.

A

Active Crossover A single or group of electronic parts responsible for dividing or blocking a frequency range or ranges. Once the frequencies are divided or blocked they are routed to the correct amplifier(s). Active crossovers operate before the power amplifier(s) in a system. Alternating Current (AC) Current produced when electrons move first in one direction and then in the opposite direction. The musical signals reproduced by an audio system are of an AC nature. Ampere 1. The electrical charge movement which is the basic unit of measurement for current flow in an electrical circuit. 2. The amount of current that flows when a pressure of 1 volt is applied across a resistance of 1 ohm. Amplifier 1. A device that increases the magnitude of an applied signal. 2. A device that receives an input signal and delivers a larger output signal.

B

Balanced Line Inputs Using the BLT (Balanced Line Transmitter) provides the last word in achievable rejection of noise induced in the cable between the source and the signal processor. The differential input circuitry used in the balanced input system rejects whatever signals are common to both of the shielded, twisted-pair conductors. Balanced line is universal in concert installations where the stage and mixing consoles are hundreds of feet apart. Long signal cables and electrically noisy environments make signal integrity and noise rejection an extremely difficult challenge. Bandpass Filter A frequency sensitive AC circuit that allows incoming frequencies within a certain band to pass through but attenuates frequencies that are below or above this band. Bass The low frequency range, generally considered to be below 100 hz. Bass Reflex Enclosure A speaker enclosure that has a vent or tube that allows the rear wave of the driver to combine with the front wave. Also called a vented or ported enclosure.

C

Capacitance The property of a device to oppose changes in voltage due to energy stored in its electrostatic field. Capacitor A device whose impedance increases with decreasing frequency. Also known as a "cap"; commonly used in passive crossovers as a high pass device. Can also be used to store energy. Crossover See Active Crossover & Passive Crossover Conductor A material that allows electrical current to flow through it easily. Conventional Current Flow Current flow that is assumed to be in a direction from high charge concentration (+) to low charge concentration (-).

D

Decibel (dB) A dB is a unit of measurement for ratios of sound level, power, voltage, and other quantities. For example, a stereo system that can reach a level of 130 dB is 130dB louder than the threshold of hearing (0dB). 130dB is 10,000,000 times louder than the quietest sound the typical human ear can perceive!! DIAMOND - formerly known as DIABLO DIAMOND (Dynamically Invariant AMplification Optimized Nodal Drive) A circuit that drives large arrays of MOSFET output transistors (Power Series amps). DIAMOND provides 20 dB of current headroom for superb sound quality and incredible dynamic range. Direct Current 1.The flow of electrons in one direction from negative to positive. 2. The type of electrical power that is produced by batteries and power supplies; used mostly for portable and specialized power applications. See electron current flow and conventional current flow. Distortion Any change in the waveform or harmonic content of an original signal as it passes through a device. The result is nonlinearity within the device. DSM (Discrete Surface Mount) DSM is an industry leading manufacturing process utilizing high speed robotics, 0% tolerance resistors and large board traces resulting in greater efficiency, less noise and higher output. DSM technology allows engineering to be more creative with circuit design making Trans•nova, Trans•ana and TOPAZ a reality. Dynamic Range The difference, in decibels, between the loudest and the quietest portions of a musical performance. Also the difference between the maximum signal level and the noise floor of electronic equipment.

E

Effective Voltage A value of an AC sine wave voltage that has the same effect as an equal value of DC voltage. Also known as RMS or Root Mean Square. Efficiency Generally speaking, efficiency is the ratio of total energy output to total energy input, expressed as a percentage. Loudspeaker efficiency is usually very low, in the 1% to 3% range, meaning 97% to 99% of the energy is dissipated as heat! A typical car audio amplifier has an efficiency of 50%. Some amplifiers efficiency ranges from 50% to about 70%, which means less current drawn from your electrical system for a given amount of power than other. Electron Current Flow Current flow that is assumed to be in the direction of electron movement from a negative (-) potential to a positive (+) potential.

F

Free Air Resonance (FS) The frequency at which a loudspeaker vibrates most easily. Free air resonance is not the only factor in determining how low a speaker will play. Frequency Warp The Frequency Warp controls shift the center frequency of each band higher or lower in frequency (up to 1/2 octave). This enables the equalizer to pin-point "dips" and "peaks" in the response curve. The frequency warp is useful when using an RTA (Real Time Analyzer) to find and correct problems located between the equalizer's center frequencies. Fuse An electrical overcurrent device that opens a circuit when it melts due to excess current flow through it.

G

G-Class The G-Class circuit is a high efficiency topology that works like a supercharger for your amplifier. When the primary power supply runs out of headroom, a secondary supply turns on to provide supplemental power. Ground The term given to a connection with an electrical potential of zero. Used as the return path for current flow. The amount of current that flows in the "positive" side of a circuit must also flow in the "ground" side as well. Ground Loop A term given when two or more devices have grounds that are not exactly at the same electrical potential. When this happens there will be current that flows between the ground points due to this difference. This current appears as signal on the audio cables which can be amplified by the system, sometimes causing audible whine.

H

Hertz (HZ) The unit of measurement of frequency. 1 hertz equals 1 cycle per second. A speaker producing a 50 HZ tone is moving back and forth 50 times per second! High-Level Inputs The High-Level Inputs convert the speaker line outputs (high level) to preamp line inputs (low level). This allows the amplifier to be compatible with a variety of source units as well as to integrate into factory systems without the need for external adapters. High-Q Filters Hi-Q filters are utilized for adjusting narrow frequency bands in an equalizer. Filter "Q" or Quality Factor is a measure of the "narrowness" of the filter response. Using Low-Q (narrow) filters in a equalizer allows adjustments made on one control to strongly affect neighboring frequencies during boost or cut. Hi-Q filters avoid problems like adjacent band overlap which minimize the time needed to adjust out frequency response errors. High Pass Filter A filter used to pass frequencies higher than a predetermined point. Frequencies lower than the F3, or crossover point, are attenuated at a rate determined by the design of the filter. Hologram Laser Some CD players feature high reliability and accuracy with the use of a Hologram laser. The hologram laser uses a sophisticated one-piece assembly versus conventional discrete lasers that use several mechanical parts. In addition, the multi-damping system for the CD mechanism acts like rubber shock absorbers to prevent skipping under rough conditions.

I

Impedance The combined effect of a speaker's resistance, inductance, and capacitance that opposes the current fed to it. It is measured in ohms and varies with the frequency of the signal. INDIGO INDIGO (INDexed Ideal Gain Operation) Some power supplies operate at different indexed regulation gains or power levels as needed. This special INDIGO design power supply lets the amplifier optimize its performance by making better use of the power that is in the car. INDIGO tightly regulates the front end (low level) components and, at the same time, allows the output components to swing with battery voltage. This allows the amplifiers to deliver more power than amplifiers that are completely operating with tightly regulated power supplies only. The result is more clean sound through the front end and very tight bass. Input Switches The Input Switches allow 4-channel amplifiers to be driven with either 2 or 4 pairs of inputs. 5-channel amplifiers can be driven with either 2, 4, or 6 inputs. The number of inputs used depends on the number of outputs the source unit has to offer. Inductance The property of an electric circuit that opposes a change in current flow. Inductor A device whose impedance increases with increasing frequency. Also known as a coil; commonly used in passive crossovers as a low pass filter device. Infinite Baffle An enclosure that is larger than the VAS of the driver, or, any baffle board where there is no path for the energy from the rear of the woofer to meet the energy from the front of the woofer. Insulator A material that offers a high resistance to electrical current flow. IR Remote A transmitter that controls a distantly located device via infrared rays. Infrared rays are invisible because their operating frequency is lower than those of visible red light. ITS ITS (Increased Thermal Stability) is a power supply design which utilizes a transformer with extended secondary or output leads. These leads are carried directly to the switching MOSFETs rather than through the circuit board. This minimizes resistance in the power supply and increases cooling.

J

K

Kilohertz (kHz) 1000 cycles per second. A speaker producing a 10kHz tone is moving back and forth 10,000 times per second!

L

Loudspeaker An electromechanical device capable of reproducing sound. A signal from an amplification device is fed to the voice coil of the loudspeaker which produces a magnetic field. This coil is mounted inside a fixed magnetic field from a permanent magnet. These two magnetic fields interact with one another, which causes the loudspeaker cone to vibrate. This vibrates the air, which our ears perceive as sound. Low Pass Filter A filter used to pass frequencies lower than a predetermined point. Frequencies higher than the F-3, or crossover point, are attenuated at a rate determined by the design of the filter.

M

Midrange A range of frequencies in the middle of the audio spectrum. Also the term for a loudspeaker capable of reproducing those frequencies. MEHSA MEHSA (Maximum Efficiency Heat Sink Application) is a proprietary process that yields up to 5 times better heat transfer than traditional FET mounting techniques using the exact same components. A multi-layer insulated metal substrate operating with minimal thermal resistance spreads heat both downward & outward to quickly dissipate heat from each device across the heat sink. This process combined with our DSM technology and MOSFET devices allow us to squeeze more watts per cubic inch from every output device as well as provide consistent thermal stability. Milliampere A unit of measurement of electric current equal to 1/1000th of an ampere. MIR The MIR (Multipath Interference Rejection) circuit improves audio performance under difficult reception conditions. The tuner slowly tapers from stereo to monoaural when excessive static is produced due to poor radio reception in fringe areas. This feature is virtually undetectable by the listener due to its smooth transition from monaural back to stereo. The MIR circuit improves audio quality by reducing multipath effects in both weak and strong signal conditions. MOSFET (Metal Oxide Semiconductor Field Effect Transistor) Some amps uses MOSFET devices in both the power supply and output stages of amplifiers. MOSFET devices offer important advantages over the 30 year old technology of bi-polar design. These advantages include: thermal stability, switching speed, ultra low output impedance and wider bandwidth linearity. MOSFETs operate very similary to vacuum tubes in that they are more linear than bi-polar transistors. However, MOSFETs can deliver the midrange clarity without the limitations of trasient response and high frequency phase shifting normally associated with tube operation.

N

NOMAD (NOn Multiplying Advanced Decision) An intelligent protection circuit that uses an analog computer to make real time decisions regarding temperature, voltage, current and impedance. Result: An amplifier with "intelligent" protection that will protect itself but will not limit the "punch" in your amp!

O

Octave A doubling or halving of frequency. For instance, 50 Hz to 100 Hz is one octave, as is 20 kHz to 10 kHz. Ohm (W) The unit of measurement of electrical resistance. Ohm's Law The law that explains the relationship of voltage, current, and resistance in electrical circuits. For example: V = I x R; I = V / R; R = V / I Open Circuit A circuit that has a broken path so that no electrical current can flow through it.

P

Parallel Circuit 1. A circuit in which the components are connected across each other. 2. A circuit whose component leads bridge common conductors like a ladder. Pass-Thru The Pass-Thru output provides a convenient source for daisy-chaining an additional amplifier without the need for extra RCA cables or "Y" adapters. The Pass-Thru signal is derived by summing the Front And Rear Left inputs to create a LEFT OUTPUT, and summing the Front and Rear Right inputs to create a RIGHT OUTPUT. Passive Crossover A single or group of electronic parts responsible for dividing or blocking a frequency range or ranges. Once the frequencies are divided or blocked they are routed to the correct speakers. Passive crossovers operate after the power amplifier in a system. Phase Warp The Phase Warp is a variable control used to adjust the phase of the output signal relative to the phase of the input signal. The phase warp is most noticeable when the system is playing a sine wave (test tone). When used with the proper test equipment, this feature can increase the relative SPL in a system. Port 1. A vent or open tunnel which allows the passage of air in and out of a loudspeaker enclosure. 2. A specified opening or tunnel used to "tune" a vented enclosure. Potentiometer A variable-resistance component used as a control device in an electrical circuit. Power The rate at which work is accomplished. The product of voltage and current. Progressive Dual Laminated Flat Spider A progressive dual laminated flat spider is employed to provide a stronger suspension for the woofer. A secondary spider is fused to the primary spider near the critical voice coil bonding point. The combinaiton of these two spiders, in addition to the progressive rolls, provides the ultimate in linear control for higher excursion capability.

Q

R

Resistance The opposition to the flow of electrical current in a circuit or material. Its unit of measurement is the ohm (W). Root Mean Square (RMS) See Effective Voltage

S

Semiconductor A material that has electrical resistance somewhere between a conductor and an insulator. Series Circuit A circuit whose components are connected in a string, i.e., end to end like a chain. Series-Parallel Circuit The interconnection of components in series and in parallel to obtain greater power dissipation than with a single component. Traditionally in speakers, each component is of the same value (i.e., all 4 ohm or 8 ohm). Short Circuit A circuit that forms a direct path across a voltage source so that a very high and possibly unsafe electrical current flows. Speaker See Loudspeaker

T

TOPAZ (Tracking Operation Pre-Amplifier Zone) This circuit eliminates ground loops by referencing signal ground from the first component in the chain. 80% of noise problems are created by ground loops. Now, with TOPAZ we have eliminated 80% of your headaches. TRANS•ana (TRANSconductance Active Nodal Amplifier) A circuit that simplifies the input path allowing the signal to travel through the amplifier at a low voltage. TRANS•ana achieves current and voltage gain in a single stage, putting less circuitry between the listener and the music. TRANS•nova (TRANSconductance Nodal Voltage Amplifier) A proprietary circuit that simplifies the signal path of the amplifier, allowing the signal to travel through the amplifier at a low voltage. The result: Greater reliability, cleaner performance and exceptional musicality with the speed, durability and power of MOSFETs. Treble The highest frequencies in the audible spectrum. Tweeter Usually a small loudspeaker suited to reproduce high frequencies.

U

V

Voice Coil See loudspeaker. Volt The unit of measurement of electrical potential. Voltage Electrical force, or pressure, that causes current to flow in a circuit. Voltage Drop The electrical potential (voltage) that exists across two points of an electrical circuit.

W

Watt The unit of measurement of electrical or acoustical power. The amount of power converted when 1 ampere of current flows under a pressure of 1 volt. Woofer Usually a large loudspeaker suited to reproduce low frequencies.

X

Y

Z