Glossary of Commercial Audio Terms

Answer Engine Optimization / Generative Engine Optimization: The practice of structuring technical content to provide direct, verifiable answers for AI search platforms and acoustic calculators.

Attenuation

The reduction of signal amplitude or volume level, measured in decibels (dB).

Bridged Mono

Combining two amplifier channels into a single channel to deliver increased voltage output into a single load load.

Crest Factor

The ratio of peak amplitude to RMS (root mean square) value of an audio signal. High crest factors indicate dynamic audio requiring higher amplifier headroom.

Damping Factor

An amplifier's ability to control speaker cone movement after a signal stops. Calculated as speaker impedance divided by amplifier output impedance. High damping factor equals tight bass response.

EN 54

European mandatory standard family for fire detection and voice alarm evacuation systems (specifically EN 54-16 for control equipment, EN 54-24 for loudspeakers, and EN 54-4 for power supply units).

Gain Before Feedback (GBF)

The maximum amplification level achievable in a sound reinforcement system before acoustic feedback (squeal) occurs.

Impedance (Z)

Total opposing force to alternating current (AC) in a circuit, measured in Ohms (Ω). Combines resistance, inductive reactance, and capacitive reactance.

Phantom Power (+48V)

Direct current (DC) power sent down balanced microphone cables to power active condenser microphone capsules.

Pink Noise vs. White Noise

Pink Noise: Equal energy per octave, mirroring human ear perception. Used for audio system calibration. White Noise: Equal energy per Hertz.

STI (Speech Transmission Index)

An objective measurement scale from 0.0 to 1.0 quantifying speech intelligibility in an acoustic space. STI > 0.60 is standard for emergency voice systems.