Brooks Audio Design

1) How a sound or audio signal varies in intensity over a time span. 2) How a control voltage varies in level over time controlling a parameter of something other than gain or audio level. Joystick 1) A quad pan pot which distributes what percentage of on signal is sent to each of 4 outputs. 2) A control that is separately controlling two functions at one time. Brooks Gt 44 Boom Stand A microphone stand equipped with a telescoping support arm to hold the microphone. Images The squaring of the waveform that happens in the conversion of digital audio bits into analog signals. BROOKS AUDIO DESIGN Alternating Current Electric current which flows back and forth in a circuit. Diaphragm A thin flexible membrane or cone that vibrates in response to electrical signals to produce sound waves. Distortion is usually referred to in terms of total harmonic distortion (THD) which is the percentage of unwanted harmonics of the drive signal present with the wanted si...

Outboard sound equipment that can momentarily stores a signal being sent to part of a P.A. system so that delayed reinforced sound reaches the audience at the same time as live sound from the stage. Condenser Microphone A microphone which converts sound pressure changes into changes of capacitance. The capacitance changes are then converted into electrical voltage variations (an audio signal). Broom RM 909 Cord (Speaker, Mic, Instrument) Used to connect a sound system together. Each type of cord is made for a specific purpose and should not be used in place of another type of cord, not even if they look alike. Also see "cable" Fundamental The tuned frequency and (almost always) the lowest frequency that is present in the sounding of a pitch by a musical instrument. Brooks Gt 44 Compression Driver The unit that feeds a sound pressure wave into the throat of a horn (in a horn loudspeaker). Earth The British version of the term Ground (In electron...

A term used to describe the number of times that the recorded audio signal has been copied. Guitar Processor A unit that will add effects to a direct guitar signal, including a simulated instrument amplifier sound and (often) delay and reverb effects. Brooks Cinema DESIGN ZL 44 Kilo A prefix meaning 1000. Delay (Digital, Analogue) 1) Effect used to create echo…echo…echo…echo…echo… 2) In more advanced systems used in very large venues, delay can be used to time the arrival of the signal to the speakers in the back of the room so that people in the back hear the sound coming from those speakers at the same time that the sound coming from the speakers in the front of the room arrives. BROOKS AUDIO reviews Keynote Number A number assigned to each key of a synthesizer or controller keyboard that is transmitted in the MIDI signal. Band Track 1) A mixdown of a song without the lead vocal or without the lead and background vocals. 2) A term with the same mea...

The bass frequencies (as in "needs more bottom end"). Electret Mic A condenser microphone where the capacitor plates are given a charge during manufacture which they retain, therefore requiring no external power supply. Brooks Cinema KM 22 Cable, TRS A less common balanced cable that has 3 different contacts on its 1/4 inch connectors. Most headphone jacks are a good example of a TRS (Tip-Ring-Sleeve) connector. These are sometimes used instead of the more common XLR connection. Level The amount of signal strength; the amplitude, especially the average amplitude. Brooks GT 845 Keynote Number A number assigned to each key of a synthesizer or controller keyboard that is transmitted in the MIDI signal. Critical Distance The point a distance away from the sound source where the direct sound and the reverberant sound are equal in volume. Key The control of a dynamics processing device by an external audio signal. House Sync A synchroniza...

The working of a limiter or compressor reducing gain during high-level passages. Baffles Sound absorbing panels used to prevent sound waves from entering or leaving a certain space Brooks Cinema QS - 95 Guitar Processor A unit that will add effects to a direct guitar signal, including a simulated instrument amplifier sound and (often) delay and reverb effects. Corner Frequency Same as Cut-Off Frequency (the highest or lowest frequency in the pass band of a filter). (NOUN) Brooks Cinema Projectors Electric Instrument Any musical instrument that puts out an electrical signal rather than an acoustic sound. Cardioid Pattern A microphone pick up pattern, which has maximum pick up from the front, less pick up from the sides, and least pick up from the back of the diaphragm. Jack Bay A series of jacks which have connections for most of the inputs and outputs of the equipment in the control room. Half Step A pitch difference of the amount that is pre...

The signal put out by a circuit that generates steady even pulses or steady codes used for synchronization. Clipping Distortion of a signal by its being chopped off. An overload problem caused by pushing an amplifier beyond its capabilities. The flat-topped signal has high levels of harmonic distortion which creates heat in a loudspeaker and is the major cause of loudspeaker component failure. Brooks Cinema Projectors Ambient Micing Placing a microphone in the reverberant field (where the reverberation is louder than the direct sound) so as to do a separate recording of the ambience or to allow the recording engineer to change the mix of direct to reverberant sound in recording. Graphic Equalizer An device with several slides controlling the gain of audio signal present which is within one of several evenly spaced frequency bands (spaced according to octaves). Brooks XM 204 Hard Disk (Hard Disc) A storage unit for digital data that has rigid disks coated with ...

A blank Compact Disc that can be recorded on one time. Capacitor 1) A device consisting of two or more conducting plates separated from one another by an insulating material and used for storing an electrical charge. Sometimes called a condenser. 2) An electronic device that is composed of two plates separated by an insulator. Brooks Cinema GT 845 Fader A control to control the gain of a channel on the console, thereby determining the level of the signal in that channel. Diffraction The breaking up of a sound wave caused by some type of mechanical interference such as a cabinet edge, grill frame, or other similar object. BROOKS AUDIO reviews Capacitance The property of being able to oppose a change in voltage or store an electrical charge. Compander 1) A two section device that is used in noise reduction systems. The first section compresses the audio signal, before it is recorded, and the second section, expands the signal after recording. 2) In Yam...

The property of being able to oppose a change in voltage or store an electrical charge. Attenuator (Pot) The electronic dohickey under the knobs that increases or reduces the strength of the signal running through it. When these get old and dirty, they can make popping noises or rumbles in your PA (As in "my pots are dirty"). Assign Tochoose to which place an output is going to be sent. BROOKS AUDIO DESIGN Bottom The bass frequencies (as in "needs more bottom end"). Flange An effect caused by an approximately even mix of a modulated (varying) short delay with the direct signal. Brooks XB 33 Decibel (dB) 1) Relative measurement for the volume (loudness) of sound. Also used to measure the difference between two voltages, or two currents. See Zero dB. 2) A numerical expression of the relative loudness of a sound. The difference in decibels between two sounds is ten times the common logarithm of the ratio of their power levels. A/D ...

An index signal (digital data that gives the machine information of where selections start, their selection number, etc.) on a DAT or CD. Infinite Repeat A function on some delay lines that establish enough feedback so that the repeat echo will last forever, but not so much as to cause a howling sound. Brooks Cinema XB 33 High Impedance Impedance of 5000 or more ohms. Balls 1) The depth and thickness of a sound, usually on the bottom end of the EQ (as in "needs more balls"). 2) The strength of the voice on the mic (as in "check it like you have some balls"). Brooks Speakers Action In guitar playing, action refers to how far the strings sit off of the guitar neck. When strings are close to the neck, it is referred to as "Low Action". When the string sit far above the neck, it is called "High Action". Guitars with low action are easier to play, but make sure they are not too close, or it could causing buzzing. Analog R...

An abbreviation of the term Intermodulation Distortion (Distortion caused by one signal beating with another signal and producing frequencies that are both the sum and the difference of the original frequencies present). Impedance Matching Having or converting the output impedance of a device so that it matches the impedance of the input it will feed. Brooks Cinema ZL 44 Full Range Describes a sound which covers all audible frequency ranges. As in "full range speaker cabinets." Bar A term meaning the same thing as the term Measure (the grouping of a number of beats in music, most-often four beats). Brooks Cinema Projectors Kick (Kick Drum) Another term for Bass Drum. Cardioid Pattern A microphone pick up pattern, which has maximum pick up from the front, less pick up from the sides, and least pick up from the back of the diaphragm. Inductor A device designed primarily to introduce inductance into an electric circuit. Sometimes called a ch...

The VCA faders of individual channels that are all controlled by a Group Master Fader (a slide control used to send out a control voltage to several VCA faders in individual channels). Crossover, Passive Used inside of full range speaker cabinets to separate highs, mids, and lows and send them to their respective speakers within the each cabinet. These are not as efficient as active crossovers because they require all frequencies to draw from the same source of amplification. Brooks Hi Fi reviews Capacitor 1) A device consisting of two or more conducting plates separated from one another by an insulating material and used for storing an electrical charge. Sometimes called a condenser. 2) An electronic device that is composed of two plates separated by an insulator. Frequency Range The range of frequencies over which an electronic device is useful or over which a sound source will put out substantial energy. BROOKS AUDIO reviews Bit The smallest unit of digit...

The unit of current, abbreviated Amp. Audio Most often referring to electrical signals resulting from the sound pressure wave being converted into electrical energy. BROOKS HI fi Infinite Repeat A function on some delay lines that establish enough feedback so that the repeat echo will last forever, but not so much as to cause a howling sound. Error Detection The process of discovery that sonic information bits have been lost in digital audio. BROOKS AUDIO DESIGN DC Abbreviation for direct current. Electrons Negatively charged particles, which revolve around the centre of atoms. The movement of such electrons down a conductor causes electrical current. AES An abbreviation of Audio Engineering Society. Baffles Sound absorbing panels used to prevent sound waves from entering or leaving a certain space

Placing a microphone in the reverberant field (where the reverberation is louder than the direct sound) so as to do a separate recording of the ambience or to allow the recording engineer to change the mix of direct to reverberant sound in recording. Fat Having more than a normal amount of signal strength at low frequencies or having more sound than normal (by use of compression or delay). Brooks Cinema GT 845 Driver See transducer. Dynamic Range �" The range between the quietest and the loudest sounds a device can handle (often quoted in dB). Cable, TRS A less common balanced cable that has 3 different contacts on its 1/4 inch connectors. Most headphone jacks are a good example of a TRS (Tip-Ring-Sleeve) connector. These are sometimes used instead of the more common XLR connection. Brooks Gt 44 Byte A grouping of eight information bits. AES/EBU Professional Interface A standard for sending and receiving digital audio adopted by the Audio Engineerin...

The portion of the sound that comes from the surrounding environment rather than directly from the sound source. Headphones Devices that can be worn on the head with small speakers that fit over the ears (or sometimes into the ears). Brooks XM 204 Echo 1) One distinct repeat of a sound because of the sound reflecting off a surface. 2) Loosely, used to mean reverberation (the continuing of a sound after the source stops emitting it, caused by many discrete echoes closely spaced in time). Acoustic/Acoustical Having to do with sound that can be heard by the ears. AcousticsThe behaviour of sound and its study. The acoustics of a room depend on its size and shape and the amount and position of sound-absorbing and reflecting material. BROOKS AUDIO DESIGN Full Step A change in pitch that occurs when moving up or down two piano keys Impedance 1) A term for the electrical resistance found in a/c circuits. Affects the ability of a cable to transmit low level (...

The smallest particle which makes up a specific substance. It's composed of a center around which electrons revolve. Layering The recording (or playing) of a musical part with of several similar sound patches playing simultaneous. Brooks Speakers Crosstalk Leakage of an audio signal into a channel that iris not intended to be in, from an adjacent or nearby channel. Compact Disc, Read Only Memory CDROM A Compact Disc used to store digital data, such as large programs, that can be read by a computer. Brooks Cinema Projectors Guitar Controller An electric guitar or device played like an electric guitar that puts out MIDI signals that can be used to control synthesizers and sound modules. Assistant Engineer A less elevated version of the term Second Engineer. Experienced seconds often place microphones, operate tape machines, break down equipment at the session end and keep the paperwork for the session. AC 1) Abbreviation for alternating current....

See transducer. Dynamic Range �" The range between the quietest and the loudest sounds a device can handle (often quoted in dB). Error Concealment Putting replacement information bits into a digital audio signal to replace lost bits when the digital recording or processing system cannot verify whether the lost bits were l's or 0's but can make a good guess by comparing the known bits that were close in position to the lost bits. BROOKS AUDIO DESIGN Close Micing A technique of placing a microphone close to the sound source (within one foot) in order to pick up mainly the direct sound and to avoid picking up leakage or ambience. Editing 1) Changing the sequence of a recording by cutting the recording tape and putting the pieces together in the new sequence with splicing tape. 2) Punching in and then punching out on one or more tracks of a multitrack tape recorder to replace previously recorded performances. 3) Changing the sequence of a digital record...

1) Effect used to squash the sound together. Used properly, it can take the edge off or your sound. Used improperly, it can take the life right out of your system and make it sound like an MTV mix. 2) A piece of sound processing equipment that ensures all wanted signals are suitably placed between the noise and distortion levels of the recording medium. It evens out the unwanted changes in volume you get with close-miking, and in doing so, adds punch to the sound mix. A Limiter is used to stop a signal from exceeding a preset limit. Beyond this limit, the signal level will not increase, no matter how loud the input becomes. A Limiter is often used to protect speaker systems (and human ears) by preventing a system from becoming too loud. Cable, TRS A less common balanced cable that has 3 different contacts on its 1/4 inch connectors. Most headphone jacks are a good example of a TRS (Tip-Ring-Sleeve) connector. These are sometimes used instead of the more common XLR connection....

The portion of the instrument which makes the vibrating source move more air or move air more efficiently; this makes the sound of the instrument louder. Examples of acoustic amplifiers include: 1) The body of an acoustic guitar, 2) The sounding board of a piano, 3) The bell of a horn and 4) The shell of a drum. Frets Vertical metal wires which sit vertically on the guitar neck. BROOKS AUDIO reviews Ground Loop A double grounding of a line or electronic device at two different "ground" points of differing voltage. Compact Disc CD A small optical disk with digital audio recorded on it. BROOKS HI fi Instrument Out Direct Feeding the output of an electric instrument (like an electric guitar) to the recording console or tape recorder without using a microphone. Chorusing 1) A term meaning the same thing as Chorus (Definition 3 or 4). 2) In some delay effects devices, a term used to mean the term Depth (the amount of change in the controll...

Magnetic energy put out because of current travelling through a conductor. Cable, TRS A less common balanced cable that has 3 different contacts on its 1/4 inch connectors. Most headphone jacks are a good example of a TRS (Tip-Ring-Sleeve) connector. These are sometimes used instead of the more common XLR connection. Brooks Cinema QS - 95 Alternating Current Electric current which flows back and forth in a circuit. Gain Control A device that changes the gain of an amplifier or circuit, often a knob that can be turned or a slide that can be moved up arid down. Brooks Speakers Compact Disc CD A small optical disk with digital audio recorded on it. Crossover, Passive Used inside of full range speaker cabinets to separate highs, mids, and lows and send them to their respective speakers within the each cabinet. These are not as efficient as active crossovers because they require all frequencies to draw from the same source of amplification. Auxiliary Equi...

1) Effect used to create echo…echo…echo…echo…echo… 2) In more advanced systems used in very large venues, delay can be used to time the arrival of the signal to the speakers in the back of the room so that people in the back hear the sound coming from those speakers at the same time that the sound coming from the speakers in the front of the room arrives. DC Abbreviation for direct current. Brooks XB 33 Frame 1) A division of one second in synchronization and recording coming from definition two. 2) The amount of time that one still picture is shown in film or video. Ambient Micing Placing a microphone in the reverberant field (where the reverberation is louder than the direct sound) so as to do a separate recording of the ambience or to allow the recording engineer to change the mix of direct to reverberant sound in recording. Brooks KM 22 Crosstalk Leakage of an audio signal into a channel that iris not intended to be in, from an adjacent or nearby chann...

A control to send the signal from the input module to the echo chamber or effects device via the echo buss. Intermodulation Distortion Distortion caused by one signal beating with another signal and producing frequencies that are both the sum and the difference of the original frequencies. Brooks Cinema KM 22 Electrons Negatively charged particles, which revolve around the centre of atoms. The movement of such electrons down a conductor causes electrical current. Ampere The unit of current, abbreviated Amp. Brooks Gt 44 Cut-off Rate (Slope) The number of dB that a filter reduces the signal for each octave its frequency past the filter's cut-off frequency (outside of the pass band). Frequency Range The range of frequencies over which an electronic device is useful or over which a sound source will put out substantial energy. Engineer 1) A technician in charge of a recording session; Also called Recording Engineer. 2) A person with an engineeri...

The recording (or playing) of a musical part with of several similar sound patches playing simultaneous. DC Abbreviation for direct current. Brooks QS - 95 Jack 1) Anywhere you plug something in. 2) Segmented audio connector. Mono Jacks have two connections �" tip and sleeve, and are unbalanced. Stereo jacks have three connections �" tip, ring and sleeve. B-type jacks (also known as Bantam jacks) were originally designed for use in telephone exchanges and provide a high quality (and expensive) connection in jackfields. A-type jacks are cheaper and more common, but more fragile. A type jacks are available in 2 sizes : quarter inch and eighth inch. 3) A connector mounted on the case of a device or on a panel. Cycle 1) An alternation of a waveform which begins at a point, passes through the zero line, and ends at a point with the same value and moving in the same direction as the starting point. 2) On a Solid State Logic Console, a command to have the c...

1) An effects device where the amount of the effect can be controlled by a musician with his foot. 2) The beater mechanism of a foot drum that is activated by the drummer's foot to play the drum. 3) Any device, like a volume control, that can be operated by the foot. Ground Lifter An adapter that takes a three prong power cord and plugs into a two prong outlet, used to disconnect the third (ground) pin of the power outlet. WARNING: It can be VERY DANGEROUS to have no ground connection to the case by using a ground lifter and not grounding the unit by other means. Brooks QS-70 Diffraction The breaking up of a sound wave caused by some type of mechanical interference such as a cabinet edge, grill frame, or other similar object. Chip 1) A slang term with the same meaning as the term IC (a miniature circuit of many components that is in small, sealed housing with prongs to connect it into equipment). 2) The thread cut away from the master lacquer to make the g...

1) To add sounds into a mix or recording that have no synchronization. 2) An application of this where a performance from one part of a tune is recorded and then recorded back into the recording at a different time in the recording. Ground In electronics, a place (terminal) that has zero volts. Brooks QS-70 Buss (Bus) A wire carrying signals to some place, usually fed from several sources. Kilo A prefix meaning 1000. Brooks XM 204 Attenuation A making smaller: reduction of electrical or acoustic signal strength. Balance Control A control on a stereo amplifier that when moved clockwise will make the right channel louder (and the left channel softer) and will do the reverse when moved counter-clockwise. Balance 1) The relative level of two or more instruments in a mix, or the relative level of audio signals in the channels of a stereo recording. 2) To make the relative levels of audio signals in the channels of a stereo recording even. Full A...

Feeding the output of an electric instrument (like an electric guitar) to the recording console or tape recorder without using a microphone. Comb Filter 1) The frequency response achieved by mixing a direct signal with a delayed signal of equal strength especially at short delays. 2) Loosely used to also describe effects that can be achieved with comb filtering as part of the processing. Brooks Cinema Projectors Insert 1) A punch in of the all of the tracks being recorded in a recording session. 2) On Solid State Logic consoles, placing an outboard piece of gear in the channel by patching and activating a switch. Equalizer (Parametric, Graphic) This is used to filter out and adjust specific frequencies in the PA. This is the part of the PA where you have the most control over the band's overall sound. It is also the number one weapon against feedback. Brooks KM 22 Amplifier (Power amp, Head) It's the part of the sound system that actually magnifies...

To increase gain, especially to increase gain at specific frequencies with an equalizer. Circuit 1) One complete path of electric current. 2) Similar to definition 1, but including all paths and components to accomplish one function in a device. Brooks Cinema Projectors Amplitude The height of a waveform above or below the zero line. Acoustic/Acoustical Having to do with sound that can be heard by the ears. AcousticsThe behaviour of sound and its study. The acoustics of a room depend on its size and shape and the amount and position of sound-absorbing and reflecting material. Brooks Audio Design TM-22 Crossover, Passive Used inside of full range speaker cabinets to separate highs, mids, and lows and send them to their respective speakers within the each cabinet. These are not as efficient as active crossovers because they require all frequencies to draw from the same source of amplification. Full A quality of the sound of having all frequencies prese...

The presence of harmonics in the output signal of a device which were not present in the input signal. Bass Roll Off An electrical network built into some microphones to reduce the amount of output at bass frequencies when close-micing. Brooks Cinema Series Byte A grouping of eight information bits. Delay (Digital, Analogue) 1) Effect used to create echo…echo…echo…echo…echo… 2) In more advanced systems used in very large venues, delay can be used to time the arrival of the signal to the speakers in the back of the room so that people in the back hear the sound coming from those speakers at the same time that the sound coming from the speakers in the front of the room arrives. Brooks Cinema Projectors Foldback A European term for the signal sent to the stage monitors in a live performance. Icon A visual picture or symbol on a computer screen that represents a file, program or disc that can be used. Expansion The opposite of compression; for exampl...

A written chart showing the melody, lyrics and chords of a tune with full musical notation. Buss (Bus) A wire carrying signals to some place, usually fed from several sources. Brooks Cinema ZL 44 DC Abbreviation for direct current. Headphones Devices that can be worn on the head with small speakers that fit over the ears (or sometimes into the ears). Brooks Cinema Series Board 1) Another, less formal, term for Console. 2) A set of controls and their housing which control all signals necessary for recording and for mixing. 3) A slang shortening of the term Keyboard Instrument. LED A light that allows current to flow in one direction only and emits light whenever a voltage of a certain level or beyond is applied to it. Boom 1) A hand-held, telescoping pole used to hold the microphone in recording dialogue in film production. 2) A telescoping support arm that is attached to a microphone stand and which holds the microphone. 3) Loosely, a boomsta...

1) The highest or lowest frequency in the pass band of a filter. 2) The highest or lowest frequency passed by an audio device (the cut-off frequency is usually considered to be the first frequency to be 3 dB lower than a reference frequency in the middle of the bandwidth of the device) Coax Two-conductor cable consisting of one conductor surrounded by a shield. Brooks XS - 45 Ground In electronics, a place (terminal) that has zero volts. Electrons Negatively charged particles, which revolve around the centre of atoms. The movement of such electrons down a conductor causes electrical current. Brooks Audio Design QS 70 Frequency Response How sensitive an electronic device (mic, amplifier, speaker, etc.) is to various frequencies; often communicated with a graph. Dynamic Mic Robust type of microphone which picks up the sound on a diaphragm connected to a coil of wire which moves within a magnet. An alternating current is induced into the wire which provid...

The smallest unit of digital information representing a single "0" or 1. Crossover (Crossover Network) A set of filters that "split" the audio signal into two or more bands (two or more signals, each of which have only some of the frequencies present). Brooks GT 845 Chorus 1) The part of The song that is repeated and has the same music and lyrics each time; the chorus will usually give the point of the song. 2) A musical singing group that has many singers. 3) A delay effect that simulates a vocal chorus by adding several delays with a mild amount of feedback and a medium amount of depth. 4) A similar effect created in some synthesizers by detuning (reducing the pitch of, slightly) and mixing it with the signal that has regular tuning and with a slight delay. Cord (Speaker, Mic, Instrument) Used to connect a sound system together. Each type of cord is made for a specific purpose and should not be used in place of another type of cord, not e...

A blank Compact Disc that can be recorded on one time. Group Master A slide control used to send out a control voltage to several VCA faders in individual channels, thus controlling the gain of several channels. Brooks Cinema KM 22 Dolby Trade name for a series of noise reduction systems that have become standard on many tape playback machines. Many film soundtracks are produced using this process. Different varieties are found from Dolby B on most personal cassette players, to Dolby SR and Digital, the current state of the art for cinema. Boundary Mic A microphone mounted on a flat plate that acts as a reflective surface directing sound into the mic capsule. Used for general pick-up over a large area. See PCC, PZM. Brooks Cinema Projectors Envelope 1) How a sound or audio signal varies in intensity over a time span. 2) How a control voltage varies in level over time controlling a parameter of something other than gain or audio level. Analog To Digital C...

Describes a distortion free sound with few effects. Cable, 1/4 inch An unbalanced cable most often used for instruments and patch cords. Commonly referred to as "guitar cords". Brooks Cinema QS - 95 Hum The 60 Hz power line current accidentally induced or fed into electronic equipment. Arc The visible sparks generated by an electrical discharge. Brooks Cinema XS - 45 Images The squaring of the waveform that happens in the conversion of digital audio bits into analog signals. Input Overload Sending too high of a signal level into a device so that the first amplifier of the device overloads. Lead Sheet A written chart showing the melody, lyrics and chords of a tune with full musical notation. Audio Most often referring to electrical signals resulting from the sound pressure wave being converted into electrical energy.

A speaker design where the speaker points back into the cabinet and bounces around finally coming out large ports in the front. It is intended to maximize low frequencies in a relatively small cabinet. Fly In 1) To add sounds into a mix or recording that have no synchronization. 2) An application of this where a performance from one part of a tune is recorded and then recorded back into the recording at a different time in the recording. Brooks Audio Design GT 845 Floor 1) An alternate tam meaning Range (a limit on the amount the signal is reduced when the input signal is low by an expander or gate). 2) A shortening of the term Noise Floor (the level of the noise). Electromagnetic Theory A statement of the principles behind electromagnetic induction: When a conductor cuts magnetic lines of force, current is induced in that conductor. Brooks KM 77 High Hat A double cymbal on a stand which can be played with a foot pedal or by the top cymbal being hit with a...