Glossary – B
Background Noise – Refers to either 1) The ambient noise in a room unrelated to the instrument(s) or vocal(s) being recorded; or 2) The system noise unrelated to the recorded signal. (All electronics emit a level of noise.)
Baffles – Sound absorbing panels that are used to prevent sound waves from entering or leaving a space.
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 even out the relative levels of audio signals in the channels of stereo recording.
Balanced Cable – A cable consisting of three wires (two signal wires and a ground wire) and two connectors. The two signal wires carry the same signal in opposite polarities, providing protection against interference and noise in a balanced system. Examples of balanced cables include tip-ring-sleeve (TRS) stereo cables and XLR cables.
Balanced Mixer – A circuit or device that generates the sum and difference frequencies of two input signals.
Band – 1) A range of frequencies, often identified by the center frequency of the range. 2) A group of musicians playing together.
Band Pass Filter – A device, circuit or plug-in that allows a narrow band of frequencies to pass through the circuit, rejecting or attenuating frequencies that are either higher or lower than the specified range.
Band Stop Filter – A device, circuit or plug-in that attenuates a narrow band of frequencies in the signal, allowing frequencies outside the band to pass. The exact opposite of a band pass filter.
Band Track – (Sometimes abbreviated “Track“) A mixdown of a song minus the lead vocal and/or background vocals. In other words, a mixed track containing only the instrumental parts of the song.
Bandwidth – In signal processing, bandwidth refers to the usable frequency range of a communication channel, measured by the difference between the device’s highest and lowest usable frequencies.
Bank – 1) A collection of sound patches, sequencer data and/or operating parameters of a synthesizer’s generators and modifiers in memory. 2) A group of sound modules as a unit.
Bar – In music notation, bar is another term for measure—a specified period of time containing a certain number of beats, and marked by bar lines on each side of the written measure.
Barrier Miking – A microphone placement technique in which a microphone is placed close to a reflective surface. When done correctly, barrier miking ensures that both the direct and reflected sounds reach the microphone simultaneously, preventing phase cancellation between the two.
Basic Session – The first audio recording session for recording the basic tracks that serve as the song’s foundation (for example, the drums and bass).
Bass Reflex – A type of loudspeaker cabinet design in which a port (opening) in the speaker cabinet enhances bass frequencies. The principle is that the sound pressure generated by the back of the speaker cone inside the cabinet is routed out the port at the front of the cabinet, mixed with the sound coming from the front of the woofer. Changing the port size and position will greatly change the character of the low frequencies.
Bass – The lower range of audio frequencies up to approximately 250 Hz. A reference value.
Beaming – A phenomenon found in loudspeakers in which higher frequencies are projected straight out of the loudspeaker, rather than dispersing along with the lower frequencies. When you stand on-axis in front of the speaker, it sounds as though it is only reproducing the high frequencies, rather than the mids or lows. This phenomenon is alleviated by routing the high frequncies through horns in the loudspeaker.
Beat – 1) The steady, even pulse in music. 2) The action of two sounds or audio signals of slightly different frequency interfering with one another and causing periodic increases and decreases in volume, heard to the ear as “beats.”
Beat Mapping – The process of adjusting the tempo variations in a recorded piece of music to fit the set tempo of the project. In a DAW, this is done using time stretching tools and cuts to synchronize the transients to the appropriate tempo markers. This technique is often used, for example, to reconcile a drum or bass performance that was recorded without a click track.
Beatmatching – A technique predominantly used by DJs to synchronize the tempos of two recorded tracks, generally through the use of time stretching and pitch shifting tools, to create a seamless transition from one song into another.
Beats Per Minute (B.P.M.) – The number of steady even pulses in music occurring in one minute, defining the tempo of the song.
Bi-amplification – A technique in which high and low frequencies in a speaker or speaker system are driven by two separate amplifiers.
Bi-Directional Pattern – A microphone pickup pattern which is most sensitive to picking up sounds directly in front and back of the mic, effectively rejecting sounds coming from the sides. Also called a “figure-8 pattern.”
Binary – A numbering system in which all numeric values are described by occurrences of the symbols “0” and “1.” Most digital data is expressed in binary.
Bit – The smallest unit of digital information representing a single “0” or “1.”
Bitrate (or Bit Depth) – In digital recording, the number of computer bits used to describe each sample. The greater the bitrate, the greater the dynamic range of the sampled sound. The quality and resolution of an audio sample are described as a combination of sample rate and bitrate. (See also “Sample Rate.”)
Blending – The mixing of multiple sounds or channels together to form one sound, or mixing the left and right signals together.
Boom – A telescoping support arm attached to a microphone stand holding the microphone.
Boom Stand – A microphone stand equipped with a telescoping support arm to hold the microphone.
Boost – To increase gain at specific frequencies with an equalizer.
Bouncing – (also called “Ping-Ponging” or “Ponging“) The technique of combining and mixing multiple tracks onto one or two tracks (mono or stereo). This can be done in real-time or analog by playing the tracks through the console and recording them onto separate tracks, or digitally through a digital audio workstation. Bouncing was once used frequently by engineers to free up additional tracks for recording, but in digital workstations where tracks are virtually unlimited, this practice is basically obsolete. Today, engineers typically bounce tracks for the purpose of creating a preliminary or final mix of a song.
Boundary Microphone – An omnidirectional microphone designed to be placed flush against a flat surface (or boundary), effectively creating a “half-Omni” pickup pattern while eliminating the danger of phase issues from reflected sounds. A popular type of boundary microphone is Crown Audio’s trademark Pressure Zone Microphone (PZM).
BPM – An abbreviation of Beats Per Minute, the number of steady even pulses in music occurring in one minute which defines the tempo.
Breathing – See “Pumping and Breathing.”
Brickwall Filter – A certain type of low-pass filter exhibiting a steep cutoff slope which resembles a “brick wall.” While these filters are often found in A/D converters to prevent aliasing, their steep cutoff can introduce unwanted side-effects to the audio signal, such as phase shift.
Bridging – A technique of feeding a single input to both channels of an amplifier, then summing them into one, thereby effectively doubling the amplifier power supplied to the signal.
Bucking – A type of phase cancellation in which two identical signals or frequencies, having the same amplitude but opposite polarity, cancel one another out. Most commonly used in the context of musical instrument frequencies. EXAMPLE: a “Humbucker” guitar pickup is designed to remove or “buck” hum frequencies from the signal using this principle.
Bulk Dump – Short for System Exclusive Bulk Dump, a method of transmitting data such as the internal parameters between MIDI devices.
Bus – An audio pathway by which one or more signals, usually from different sources, are routed to a designated place. Because busses are highly connected to signal flow, they serve a broad range of purposes in audio applications. 2) A shorthand term for the signals themselves that are routed through the bus (see also “Subgroup”).
Byte – Information (data) bits in a grouping of eight. One byte = eight bits.