Frequencies & Audio Glossary – B


Backline This is the term used to refer collectively to all the musicians (and their equipment) on stage who are supporting the lead artists.
Baffles Sound energy absorbing panels used to obstruct sound waves from entering or leaving a certain space. These are usually barriers that can be moved conveniently around the recording space to achieve acoustic separation where it is required.
Balance 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 as determined by the engineer, producer or artist. To make the relative levels of audio signals in the channels of a stereo recording even with respect to volume.
Balance Control This is a control that can be used to alter the relative volume between the left and right monitors. When the control is move to the left the right channel becomes softer and the left channel becomes louder (and vice versa).
 1) this is where the frequencies across the audio spectrum are fairly even relative to each other. There is relatively even amount of low frequencies compared to mid-range frequencies and high frequencies. 2) Having an even mixture of the various instrument levels in an audio recording. 3) Having a fairly equal volume level in each of the stereo channels. 4) An electronic method of interconnecting electronic devices using three-conductor cables.
Balancing Engineer A person responsible for ensuring that a mix is balanced during a mix down session and who also technically supervises the session.
Ballistics This is the physical property of a VU needles capability of responding to an incoming signal and how precisely it moves with respect to the envelope of an incoming signal.
Balanced input/output A “balanced” connection has three electric wires to carry the signal. One is a ground, and the other two (called conductors) carry signals of equal value but are positive and negative. This is why they are called balanced. Low impedance cables (like XLR leads) and connections are the most common.
*Band Track This is a term given to a recorded musical track where all the lead elements and backing vocals have been removed (muted or not tracked). Another name for the band track is rhythm track and it is useful for artists to have if they need to practice to the track prior to recording a lead vocal or another lead element. It can also be referred to as a karaoke mix.

Bandpass Filter This is a filter that attenuates frequencies both below an above a selected frequency band or window.
Basic Tracks The basic tracks are the essential elements of a track that are usually the first to be recorded in a session. These might include guitars, bass and drums.
Basilar Membrane An anatomical component of the human hearing system (membrane inside the cochlea) that vibrates in response to sound energy.
Bandwidth This is a window of frequencies on any frequency spectrum. It may be referred to as the range of frequencies over which a tape recorder, amplifier or other audio device is useful or even the range of frequencies that will be affected by an equalization setting.
1) This is a collection of sound patches (data as to the sequence and operating parameters of the synthesizer generators and modifiers) saved in memory. 2) An array of sound samples that are saved in a keyboard or sound module.
Bar In musical notation this word means the same thing as the term Measure (the grouping of a number of beats in music).
Barrier Miking An audio engineering method of placing the head of a microphone in close proximity to a reflective surface, in order to preventing phase cancellation.
Basic Session The initial recording session designed to record the Basic Tracks required for the production.
1) The lower range of audio frequencies up to approximately 250 Hz.
2) Short for Bass Guitar.
3) Lower end of the musical scale. In acoustics, the range (below about 200 Hz) in which there are difficulties, principally in the reproduction of sound, due to the large wavelengths involved.
4) The lower frequencies.
5) On the soundboard this should refer to the bass guitar channel, not the bass drum.
6) The lowest frequencies of sound. Bi-Amplification uses an electronic crossover or line-level amplifiers for the high and low frequency loudspeaker drivers.
Bass Boost An increase of sound level in the lower spectrum of audio frequencies.
Bass Reflex Enclosure This is also referred to as a vented enclosure and it has a hole cut into the front portion of the sound baffle.
Baud The transfer rate of a digital signal that is measured in seconds.
BCD Binary-Coded Decimal
Bass Roll Off This is essentially a function where the frequencies in lower part of the audio spectrum can be attenuated below a certain selected frequency. These frequencies can often be attenuated at a selected rate that is measured by a number of decibels per octave. If there is a bass roll of that is built into electrical hardware the option of selecting the frequencies threshold and rate of roll is not always given. On some advanced microphones there will be an option to select the frequency below which bass roll off occurs. This can help deal with proximity effect and reduce the need to equalize a recorded signal.
1) in music this is the steady pulse and the fundamental unit of time that divides the measure. 2) In physics a beat occurs when two frequencies interact and result in periodic and audible rise and fall in volume. This is due to the sonic interference that occurs between these two frequencies.
Beats Per Minute BPM This is the number of beats that occur in one minute at a constant tempo.
BEL This is a unit of measuring sound level intensity. It is expressed as the level of one sound relative to another. The Decibel (more common in audio) is one tenth of a BEL. The Bel is measured logarithmically because of the behavior of the human ear in response to volume shift.
Bi A prefix meaning two.
1) A way of optimizing the efficiency of a speaker system by separately amplifying the High Frequency (HF) and Low Frequency (LF) components of the sound signal. They are sent down two pairs of cables to the speaker. Multi-pin Speaker connectors have been developed to accommodate this function.
2)The process of having of having low-frequency speakers and high-frequency speakers driven by separate amplifiers to maximize the sound quality and efficiency of a system.
Bi-Directional Polar Pattern This is a microphone pick up pattern which has maximum pick up directly in front and directly in back of the diaphragm and least pick up at the sides. It is also widely referred to as a figure of 8 polar patter.
Bi-phase Modulation This is an encoding function in SMPTE time code where a continuous square wave alternates between the frequencies of 1200Hz and 2400Hz.
Bias This is a very high frequency that is applied to a tape machine head and it is designed to help bring about linearity in the transfer characteristics of the magnetic recording tape.
Bias Beats These are beating frequencies that can occur if two different bias frequencies are occurring at the same time. The value of the beating frequency can be calculated as the difference between the two bias frequencies.
Bias Frequency This is the frequency that is used as the bias that is designed to help align a tape machine head. Bias frequencies are usually between 120kHz and 180kHz.
Bias Oscillator This is a fixed frequency oscillator that is built into a tape machine that is designed to feed the bias current.
Bias Trap This is an audio filter that is designed to eliminate the bias frequency from a recording so that is does not over-load the tape head in the machine. It is a necessary component of studio tape machines.
Binary A numbering system based on only two numbers, usually 1 and 0. Larger numbers in the binary system can be created by stringing together one’s and zero’s. Ie. 11100101. To convert the system back to decimal each position is give the base 2 (because it is binary) with the power according to each digits unique position along the string. These values are then added to attain the value in decimal.
Binary Digit This could be either of the two digits that are available in the binary system (1 and 0).
Binary Coded Decimal This is a decimal number that has been encoded into the binary system.
Binaural Any system where the listening done is with two ears. This can be emulated in a record scenario by using two different microphones.
Binaural Recording This is recording where the microphones are designed to emulate the hearing pattern of a human. Two microphones are often placed in a position similar to that of ears on a person.
 The smallest unit of digital information representing a single “0″ or “1”.
Bit Stream This is a sequence of binary digital information that is transferred along a data bus to another location.
1) This is the condition whereby two signals mix together to form one sound or give the sound of one sound source or one performance.
 3) A method of panning during mixing where instruments are not necessarily panned hard left or right but are given a unique location in the audio mix.
Blanketed This is the colloquial term used to describe the sound of audio when the upper frequencies have been dampened. The audio begins to sound like a blanket as been placed over the signal.
Block (DATA) This is a block of digital data that is separated from of data blocks.
Block-Coded Format This is where the data is sent via in blocks through a data buss to another location.
Blumlein Pair This is where two microphones with figure of 8 polar patterns are set up so that the pick up patterns are at right angles. This is a stereo miking technique that was developed by Alan Blumlein.
Blurred This is a colloquial term that is used to describe a stereo image that is not clearly defined and bad transient response. This can come about due to factors such as poor phase.
1) A hand-held pole used to extend the reach of a microphone. It is most often used in location recording or on TV sets where the microphone should not be in the camera frame.
Boomy The colloquial term used to describe an audio signal or mix where there is excessive low to mid low frequencies present.
Bottom This is the colloquial term used to describe any of the frequencies on the audio spectrum that lie below 100Hz.
Bouncing Tracks This is the process whereby two or more previously recorded tracks are recorded on to one track. In the tape machine realm this is literally recording many previously recorded tracks on to one unused track. For example, all the drum tracks might be tracked down to one audio track. In the digital world this is the process whereby all the recorded tracks are bounced out as one audio file. It is referred to as “the bounce”. Clearly it is a very similar concept to where the term derived from in the use of tape machines.
Boxy This is the colloquial term that is used to describe a signal or mix that has resonances which are characteristic of it being inside a box. This usually derives from the signal having too much 250Hz to 500Hz.
Breathing The is a term that is used in reference to the behavior of compressors where the rising and falling of background noise is clearly audible. This is often objectionable. Another term used to describe the same effect is ‘pumping and breathing’.
Breathy This is the audibility of breathing sounds that can be heard on a recording. They could come from a sax or a flute player and often singers.
Bright This is the colloquial term used to describe a signal or a mix where there is a relatively large content of high frequencies compared to mid and low frequencies. This can also be thought of as the harmonics being relatively stronger than the lower fundamentals.
Brittle This the colloquial term that is used for harsh high frequency content that is present in the audio or weak fundamental frequencies.
Broadcast Mode This is a mode that exists on consoles where the signal is fed to the channel and monitor sections separately. Therefore, the audience, who are listening to the monitor path, while the signal is being sent live, will not hear any adjustments in the channel path.
Buffer An intermediate data storage system that allows variation in the flux of data.
Bulk Eraser This is a strong electromagnet that is used to erase magnetic recording tape. It does this by re-orientating the magnetic domains on the tape and thereby resetting the tape to be reused for new material.
Bus (DATA) This is a computer wire that is designed to transfer data.
Bus Selector Switch This is a switch that can be found on consoles that allow for signals to be sent to multiple busses if required.
Boom Stand A microphone stand equipped with a telescoping support arm to hold the microphone.
Boost In audio this means to increase the gain. This might involve increasing the gain of individual frequencies or a bandwidth of frequencies.
Boundary Mic
A microphone mounted on a flat plate that acts as a reflective surface directing sound into the mic capsule. Used to pick up acoustic energy from over a large area. See PCC, PZM.
Bridge The bridge assembly, or just “bridge” on the face of a guitar where the strings meet or are connected to the face.
1) This is a colloquial term for a recording console. 2) A set of controls and their housing which control all signals necessary for recording and for mixing. 3) A colloquial shortening of the term Keyboard Instrument.
Bouncing This is the colloquial term used to define a sound that is alternating in location in the mix. For example, some delay settings can bounce between the left and right channels. This is also called ‘ping-ponging’. Alternatively, this is the name given to a channel or newly created file where many collective elements in a mix have been transferred down to one.
BPM An abbreviation for Beats Per Minute. This is the number of steady pulses in a piece of music occurring in one minute. This defines the tempo.
Bulk Dump This is the abbreviation for System Exclusive Bulk Dump. This is a method of transmitting data, such as the internal parameters of a MIDI device, to another MIDI device.
Buss (Bus) 
A wire carrying signals to some place, usually fed from several sources. On an audio console or in a DAW this is another channel where other channels are being sent. For example, if all the components of a drum kit were recorded on to separate channels they could all be funneled down to another channel so that the overall volume of the drums could be uniformly altered without changing the volume of the individual drum channels. This would then be called the drums bus. Alternatively, if a strings section was recorded and each string part was recorded on to a separated channel the entire string mix could be sent to a bus and that could be used to control the volume of the strings uniformly. This would be called the strings bus.
Byte A grouping of eight bits in the field of computing.