Audio Glossary

A–B

24/96

Refers to audio discs created using the 2-channel DVD specification for audio. 24 bit/96,000 Hz sampling rate. Provides a noticeable improvement over the older CD 16 bit 44,100 Hz (16/44) specification.

5.1 Surround Sound

This multichannel format represents five discrete, full bandwidth (20-20kHz) channels—left, right, and center fronts, plus left and right surrounds. The .1 is the limited bandwidth (20-120Hz) subwoofer channel.

7.2.4 Surround Sound

Multi-channel format developed by Dolby for Dolby Atmos content. It consists of seven listener-level surround speakers. The .2 represents two subwoofers, and the .4 represents four overhead, or up-firing (ceiling reflective) speakers creating a 3D sound field.

ARC

Audio Return Channel. An HDMI port that can receive and send audio data. The updated standard, eARC (e=enhanced),  is capable of much higher signal density and quality.

Active Speaker

A speaker or subwoofer with a built-in amplifier.

Amplifier (Amp)

A device which boosts signal level. Many types of amplifiers are used in audio systems. Amplifiers typically increase voltage, current, or both.

Audio Frequency

The acoustic spectrum of human hearing, generally regarded to be between 20 Hz and 20 kHz.

Axis

For speakers, the imaginary line that extends out from the centerline of a speaker, optimally in straight line to the intended listener’s position.

Bandwidth

A specific range of frequencies, measured in Hertz (Hz). Common bandwidths include treble, bass, and midrange.

Bass

The low end of the audio frequency spectrum between 0 Hz to about 300 Hz.

C–D

Center Channel (Speaker)

This speaker produces voices, dialogue, and any other sound effects the director mixes into it. At home, it is ideal to position this element either directly on top of or directly below your television.

Codec

Short for Compression/Decompression. An algorithm used to store data in smaller sizes to facilitate easier transmission of that data. A good Codec preserves most of the original sound quality while impactfully reducing the amount of data required for transmission.

Coherence

A listening term which refers to how well a system’s sound is delivered to the listening position with minimal phase or delay between the various channels of audio.

Crossover

A filter circuit that divides the audio frequency spectrum (20 Hz – 20 kHz). for the purpose of providing the appropriate band of frequencies to individual speakers that specialize in a given bandwidth. Without a crossover, each driver would be receiving the entire frequency range.

DAC

Digital to Audio Converter. Translates a digital bitstream into an analog signal.

DSP (Digital Signal Processing)

Used to alter a digital input signal. Some common examples include: time delay for the rear speakers, equalization for a subwoofer, filtering low frequencies out of satellite speakers and adding effects like a concert hall.

Decibel (dB)

The measurement unit of sound loudness. One dB is considered the smallest change in loudness perceptible by humans. (0 dB = - The threshold of hearing. 130 dB = the threshold of pain.)

Discrete

Refers to distinct, separate channels in an amplifier.

Dispersion

The spreading of sound waves as they leave a speaker. A wide dispersion helps if you're sitting off-axis from the main listening position.

Dolby Atmos

Surround sound technology utilizing overhead speakers as well as the traditional surround speakers. For example, a 5.1 system with four overhead speakers would be called 5.1.4. Atmos allows up to 128 audio tracks plus associated spatial data to be distributed throughout the system.

Dolby Digital

A six-channel surround system consisting of discrete left, center, right and left rear, right rear channels and an LFE (Low Frequency Effects) Channel.

Driver

Technical name for the parts of a speaker which generate sound. For example: bass driver (woofer), treble driver (tweeter). The term is professionally used so that “speaker” can be reserved for talking about the entire driver-crossover-cabinet enclosure.

E–L

EQ (Equalizer)

Electronic device that actively filters certain frequencies, in order to increase or reduce their impact.

Front Speakers

Two speakers placed on a right and left diagonal in front of the listening position, separate from the center channel speaker.

Grain

A listening term. A sonic analog of the grain seen in photos. A sort of “grittiness” added to the sound.

HDMI

High-Definition Multimedia Interface. The standard interface between media devices that carries digital video and audio signals.

Haas Effect

The psychoacoustic effect that allows us to emulate direction using stereo sound. Any sound reproduced with latency below humans’ echo threshold (40 ms) will be interpreted as a single sound, and the delay is perceived as direction.

Height Channel Speaker

A Loudspeaker that is mounted in or near the ceiling pointed downward, or an up-firing speaker that reflects off the ceiling to create a more special experience in sound systems using Dolby Atmos Technology.

Hertz (Hz)

Denotes frequency in Cycles Per Second, (CPS): 20 Hz = 20 CPS.

Imaging

A sound system’s ability to create the illusion of the original sound sources as being localized in space.

Integrated Amplifier

Single unit containing both a preamplifier and a power amplifier. Mostly used in a stereo speaker system but can also be used in a home theater.

Low-Bass

Low frequency bass, above the sub-bass range, is around 80 Hz - 200 Hz. May also refer to large woofers because they specialize in this frequency range.

M–R

MLP

Main Listening Position. The most important seating location in a home theater.

Matrix

A technique of storing more than one audio channel on a single channel. Dolby Surround is an example, where the center and surround channels are electronically extrapolated from the left and right channels of a stereo signal.

Mid-Bass

Mid frequency bass just above the low-bass range, around 200 – 400 Hz.

Midrange

Middle bandwidth of audible signal, typically anywhere between 400 Hz and 2 kHz. Also refers to the speakers that specialize in these frequencies.

Output

The sound level produced by a speaker.

Overload

A condition wherein system input is too high, commonly causing distortion or product failure. Most receivers will go into what's called "protect mode" if the volume output is too high.

Rear Channel Speaker

A Loudspeaker that is located behind the listener in a surround sound system.

Receiver

An audio component that combines a pre-amplifier, amplifier(s) and tuner in one chassis. A home theater receiver will also contain multi-channel surround decoders, such as Dolby Digital and DTS.

S–Z

Satellite Speaker

A small speaker designed to fit more easily into the interior decor of a home. Typically they need to be used with a subwoofer.

Smart TV

This type of TV incorporates an operating system to enable internet access, web browsing, and connectivity with content streaming apps. A Smart TV does not require an external source to do this, like a Roku, FireStick, or AppleTV. Due to the built-in HDMI/ARC capability of most Smart TVs, they can interface directly with SoundSend in order to transmit multi-channel audio to WiSA Certified speakers.

Soundstage

Listening term. Perceived width and depth of sound. Speakers with a good soundstage can localize separate positions for each voice or effect.

Stereo

Derived from the Greek word meaning solid. A two-channel format designed to produce the illusion of a holographic image between the speakers.

Sub-Bass

Sub frequency bass, from 20 Hz to 80 Hz. This bandwidth is produced by a subwoofer.

Subwoofer

A speaker specializing in low frequencies. Although any location will result in bass that appears to come from the satellite speakers, they usually sound best when placed near the front speakers.

Surround Channel Speaker

A loudspeaker that is located beside or slightly behind the listener in a surround system.

Sweet Spot

A listening position that yields the best results, usually equidistant from the front (two or three) loudspeakers. Some systems can compensate for differences in from the main listening position (ML) by delaying speakers close to the MLP and also attenuating their sound slightly, both using well known sound wave transmission theory.

THX

An acronym for Tomlinson Holman Experiment, THX is a set of technical standards and performance criteria developed by Lucasfilm to ensure that moviegoers see and hear a film at optimum performance levels, “as the director intended”. This comprehensive set of standards includes rigorous specifications designed to optimize equipment, room acoustics, background noise levels, and projection and viewing angles.

Timbre

Pronounced TAM-ber. Refers to tone color, or the quality of sound that makes one instrument or voice distinct from another.

Treble (highs)

High audio frequencies, usually reproduced by tweeters. Treble range starts at about 2 kHz and up.

Voice-Matched

Speakers that are “voice-matched” have the same timbre or tonal quality. Voice-matched speakers in a home theater system will result in a convincingly seamless encompassing sound.

Watt

A power measurement for audio receivers and amplifiers. The more watts an A/V receiver produces, the more power the speakers in a system will receive.

WiSA Certified

Product designation for transmitters or speakers, meaning that they contain the firmware necessary to interface with one another seamlessly using proprietary WiSA technology. For example, Platin Monaco speakers, and the Axiim LINK & Soundsend(tm) transmitters are all WiSA Certified.

WiSA Ready

This product designation is for audio sources which are “ready” to interface with WiSA speakers when an appropriate transmitter, like the Axiim LINK, is attached. Currently, LG OLED/Nanocell TVs, as well as Xbox One/S/X and Xbox Series X are WiSA Ready.