A
- A/B testing
- Comparing two products by switching between them, ideally level-matched and blind.
- AAC
- Advanced Audio Coding — a lossy format used by Apple Music and as a Bluetooth codec.
- Active speaker
- A speaker with built-in amplification (also called powered).
- ANC
- Active Noise Cancelling: microphones and inverted sound reduce outside noise.
- Anti-skate
- A turntable setting that counters the force pulling the tonearm toward the centre.
- aptX
- A family of Bluetooth codecs (aptX, HD, Adaptive, Lossless) from Qualcomm.
- ARC / eARC
- HDMI Audio Return Channel — sends TV audio to a soundbar or receiver. eARC supports lossless and Atmos formats.
- Attenuation
- Reduction of signal level.
- AV receiver (AVR)
- A multichannel amplifier with surround decoding and video switching.
B
- Balanced connection
- A three-conductor connection (XLR or TRS) that rejects interference — standard in studios and long cable runs.
- Balanced armature (BA)
- A small, precise driver type used in many IEMs.
- Bass reflex
- A speaker enclosure with a port to extend bass.
- Bi-amping / bi-wiring
- Using separate amplifiers (bi-amping) or separate cables (bi-wiring) for a speaker’s bass and treble sections.
- Bit depth
- The precision of each digital sample (16-bit, 24-bit).
- Bitrate
- Amount of data per second in a digital audio stream, in kbps.
- Bookshelf speaker
- A compact speaker designed for stands or shelves.
C
- Cartridge
- The part of a turntable that holds the stylus and converts groove motion into an electrical signal.
- Centre channel
- The home-theater speaker above or below the screen that carries most dialogue.
- Clipping
- Harsh distortion when an amplifier or digital signal exceeds its maximum level.
- Closed-back
- Headphones with sealed cups that isolate and leak little sound.
- Codec
- A method for encoding and decoding audio, e.g. MP3, FLAC, LDAC.
- Condenser microphone
- A sensitive microphone type needing phantom power, popular for vocals.
- Crossover
- A circuit or setting that splits frequencies between drivers or between speakers and a subwoofer.
D
- DAC
- Digital-to-Analogue Converter — turns digital audio into an analogue signal.
- DAP
- Digital Audio Player — a dedicated portable music player.
- DAW
- Digital Audio Workstation — software for recording, editing and mixing.
- Direct drive
- A turntable whose motor turns the platter directly.
- Dolby Atmos
- An object-based surround format that adds height channels.
- Driver
- The part of a speaker or headphone that moves to create sound.
- DSP
- Digital Signal Processing — EQ, room correction, crossovers and effects done digitally.
- DTS:X
- An object-based surround format similar in concept to Dolby Atmos.
- Dynamic microphone
- A robust mic type, less sensitive to room noise; great for live and podcast use.
- Dynamic range
- The difference between the quietest and loudest sounds.
E
- Electrostatic
- A driver using a charged thin film between electrodes; very detailed, needs special amps.
- EQ (equaliser)
- A tool to boost or cut frequency ranges.
F
- FLAC
- Free Lossless Audio Codec — compressed files that are bit-identical to the original.
- Floorstanding speaker
- A tall, full-range speaker that stands on the floor.
- Frequency response
- How evenly a device reproduces different frequencies.
G
- Gain
- Amplification of a signal; on interfaces, the input level control.
- Ground loop
- A wiring issue causing hum, often fixed by grounding or isolating connections.
H
- Headroom
- Spare capacity before clipping — in amplifiers or digital levels.
- Hi-res audio
- Digital audio above CD resolution, typically 24-bit/48 kHz or higher.
- Hi-Z input
- A high-impedance input on an interface for guitar or bass.
I
- IEM
- In-Ear Monitor — earphones that seal in the ear canal.
- Imaging
- How precisely instruments are placed between and around the speakers.
- Impedance
- Electrical resistance to AC signals, in ohms (Ω).
- Integrated amplifier
- Preamp and power amp combined in one box.
L
- Latency
- Delay between input and output, important for Bluetooth, gaming and recording.
- LDAC
- A high-bitrate Bluetooth codec developed by Sony.
- LE Audio / LC3
- The newer Bluetooth audio standard and its efficient codec.
- LFE
- Low-Frequency Effects — the “.1” bass channel in surround soundtracks.
- Line level
- The standard signal level between sources and amplifiers.
- Lossless / lossy
- Lossless keeps all original data; lossy discards some to save space.
M
- MC / MM
- Moving Coil and Moving Magnet — the two main types of phono cartridge.
- MIDI
- A protocol for sending musical note and control data between instruments and computers.
- Monitor (studio)
- A speaker designed for accurate, neutral playback in production.
N
- Near-field
- Listening close to speakers (e.g. at a desk) so the room has less influence.
- Nominal impedance
- A simplified impedance rating, e.g. 8 Ω.
O
- Open-back
- Headphones with vented cups for a spacious sound; they leak and don’t isolate.
- Optical (TOSLINK)
- A digital audio connection using light through a fibre cable.
P
- Passive speaker
- A speaker without built-in amplification.
- Phantom power (+48V)
- Power sent through a mic cable to run condenser microphones.
- Phase
- The timing relationship between waveforms; wrong phase can cancel bass.
- Phono stage
- A preamp that boosts and equalises a turntable signal.
- Planar magnetic
- A headphone driver using a thin film between magnets.
- Preamplifier
- The stage that selects inputs and controls volume before the power amplifier.
R
- RIAA equalisation
- The standard curve applied when cutting records and reversed by the phono stage.
- RMS power
- Continuous power an amplifier can sustain — the meaningful power figure.
- Room correction
- DSP that measures and compensates for room acoustics.
S
- Sample rate
- How many digital samples are taken per second (e.g. 44.1 kHz).
- SBC
- The basic mandatory Bluetooth audio codec.
- Sensitivity
- How loud a speaker or headphone plays for a given input.
- SNR
- Signal-to-Noise Ratio — how far the signal sits above background noise.
- Soundstage
- The perceived width, depth and space of a recording.
- Stylus
- The diamond tip that tracks a record’s groove.
- Subwoofer
- A speaker dedicated to the lowest frequencies.
T
- THD
- Total Harmonic Distortion — added harmonics, as a percentage.
- Toe-in
- Angling speakers toward the listener.
- Tonearm
- The arm that holds a turntable cartridge.
- Tracking force
- The downward force of the stylus on the record, in grams.
- Transport
- A device that reads a disc or stream and outputs digital audio to a DAC.
- TWS
- True Wireless Stereo — earbuds with no cable between them.
- Tweeter
- The driver that handles high frequencies.
U
- Up-firing speaker
- A speaker angled upward to bounce Atmos height effects off the ceiling.
- USB audio
- Sending digital audio over USB to a DAC or interface.
V
- VU meter
- A needle meter showing average signal level, common on vintage amps and tape decks.
- Vinyl
- PVC records played on a turntable — LPs (33⅓ rpm) and singles (45 rpm).
W
- Woofer
- The driver that handles low frequencies.
- WAV / AIFF
- Uncompressed audio file formats.